Weather and Seasons Through the Year

You can feel that one day is warmer than another. A thermometer gives you a number to record. That number tells the air's temperature: how warm or cold it is.

Find the right scale

Weather reports in the United States use degrees Fahrenheit, written °F. Say 64°F as "64 degrees Fahrenheit." Some thermometers also show degrees Celsius, marked °C. Scientists and most other countries use that scale. Find the side marked °F for your weather diary.

In a tube thermometer, colored liquid moves up as it gets warmer. It moves down as it gets cooler. A digital thermometer shows a number on a screen.

Read the small marks

Look straight across at the top of the liquid. Looking from high above can make the reading look different.

Try this reading. The large numbers are 60 and 70. Each small mark stands for 2 degrees. The liquid stops two marks above 60.

1. Begin at 60.
2. Count 2 more: 62.
3. Count 2 more: 64.

Write 64°F. Two marks did not mean 2 degrees here. Each mark meant 2, so you counted up 4 degrees.

Measure the air

Choose a shady spot, such as under a porch roof. Sunshine heats the thermometer itself and raises its reading. Keep your thermometer in the same shady spot each day.

After moving it, wait a few minutes for the liquid to stop moving. Hold the top, away from the bulb at the bottom. Warm fingers on the bulb can raise the reading too.

Compare your numbers

A bigger temperature number means warmer air. A smaller number means cooler air. At 9 in the morning, a thermometer reads 50°F. At 2 in the afternoon, it reads 60°F. Count from 50 up to 60: the afternoon is 10 degrees warmer.

32°F is water's freezing point. Puddles can freeze when the air is that cold or colder. Snow usually falls near or below freezing.

Picture 20°F as very cold, 50°F as cool jacket weather, and 90°F as hot. Wind can make a cold day feel colder. The thermometer's number tells the air temperature; you also need to notice the wind.

Rain can leave a small puddle or a very deep one. A rain gauge catches rain so you can measure it. Rain, snow, sleet, and hail are all precipitation: water falling from clouds.

Give rain room to fall

Put the gauge in an open spot, away from trees and buildings. A roof can block rain or drip extra water into it. Branches can do the same. Set the gauge level and firm so it stays upright.

Read the depth of the water in inches. Your eyes should be level with the water's top. Read at the same time each day, write the number, and then empty the gauge. Tomorrow's reading will then show the next day's rain.

Read, record, empty

Here are three example readings:

Monday had the most rain. One inch and half an inch make 1 and a half inches altogether. Tuesday's zero means you checked and found no rain. It is different from a day you missed.

Suppose you forget to empty Monday's inch of rain. Even if Tuesday is dry, the gauge still holds Monday's water. You could write a rainy day by mistake. Emptying after every reading keeps the days separate.

Make a simple gauge

Use a clear container with straight sides and a flat bottom. Tape a ruler outside it. Line up the ruler's 0 mark with the inside bottom. A ruler's end may stick out past zero; line up the mark itself.

A wide straight-sided container catches more water than a narrow one. It also spreads that water over a wider bottom. The rain reaches the same depth in both. That is why you read the height of the water, not how many cups it holds.

Measure snow on the ground

For snow, choose a flat, open place. Push a ruler straight down until it touches the ground. Read where the top of the snow meets the ruler. Skip piles made by shovels or wind.

Snow depth and rain depth are different measurements. A cup of snow melts into much less than a cup of water. Record snow as snow depth, so your diary says what you measured.

You cannot see the air itself. You can feel it on your face and see leaves move. Wind is moving air. You can describe both its direction and its strength.

Name where wind comes from

The four main compass directions are north, east, south, and west. Their letters are N, E, S, and W. Face north: east is on your right, west on your left, and south behind you. A grown-up can help find north with a compass.

A north wind comes from the north and travels south. We name a wind for where it starts, not where it goes.

Read a weather vane

A weather vane turns on a pole. Wind pushes its wide tail away. The arrow points into the wind, toward where it comes from.

Suppose the arrow points to W. Start with that letter: west. The wind comes from the west and blows east. Write "west wind."

Watch a windsock or ribbon

A windsock is a cloth tube. Wind enters the wide opening and stretches the tube out. Its long tail points where the air is going. A ribbon tied to a stick does the same thing.

If a windsock stretches east, the air is traveling east. It came from the west. This is also a west wind, even though the sock's tail points east.

Hold a ribbon in an open place. A wall can block the wind or turn it, giving a different result.

Describe wind strength

Look for clues near you:

• Calm: leaves are still; a windsock hangs down.
• Light breeze: you feel moving air; leaves rustle.
• Windy: small branches move; flags stretch out.
• Very strong wind: big branches sway; walking is hard.

Wind can turn or become stronger during the day. Check at the same time each day for your diary. Record both parts, such as "wind from the south, light breeze."

What was the weather like last Thursday? A weather diary helps you find out. It holds observations made day after day, for weeks or months. Scientists call recorded facts data.

Make space for each observation

Give each day a row. Include the date and time, sky, rain or snow, temperature, and wind. A note about how it felt can help too.

Here is an example entry:

"Tuesday, April 7, 10:00 a.m. Partly cloudy. No rain: 0 inches. 58°F. Wind from the south, light breeze."

The temperature needs °F so readers know the scale. The wind entry needs a direction and a strength. The date helps you find this observation later.

Describe the sky

Cloud cover means how much of the sky clouds hide.

Look for rain separately. Clouds can cover the sky without rain falling. You might write "cloudy, no rain."

Small pictures called weather symbols save writing. Use a sun for sunny weather, a cloud for cloudy weather, and a cloud with drops for rain. A snowflake means snow. Make a key explaining each symbol. Keep using the same picture for the same meaning.

Keep the time and place steady

Record at the same time and place each day. Air often warms between morning and afternoon. A 9 a.m. reading and a 2 p.m. reading mix up two changes: the day and the time.

If you want to compare mornings with afternoons, make two separate columns. Keep the morning time the same each day, and keep the afternoon time the same too.

Record what happened

Write your own observation, even if it matches yesterday. If you miss a day, write "no record" or leave it empty. A guessed temperature cannot tell you what really happened.

Some days change after your observation time. You could write "sunny at 10 a.m.; rain after lunch." That keeps the morning record clear while saving the later change. A zero in the rain column means you checked; an empty space means the observation is missing.

A page of weather records holds many small facts. Counting puts them together. You can find the most common weather and compare warm and cool days.

Count every day once

First decide how days will go into groups. For example, "If rain falls at our check time, count a rainy day." Put each day in just one group. A cloudy, rainy day then goes in the rainy group, not both.

Use tally marks: one mark for one day. The fifth mark crosses the first four. Each bundle is worth 5. Two bundles and two extra marks make 12: count "5, 10, 11, 12."

A class recorded these April totals:

Check that no day was missed or counted twice:

April has 30 days, so this total fits a full month.

Make the graph fair

A picture graph uses pictures to show counts. Use one same-sized picture per day. A bar graph uses bars. In your class graph, each square in a bar can mean one day.

Start all bars at the same line. Make every square the same size. Label the kinds of weather and add a title. Otherwise, a bar could look longer just because its squares are bigger.

The sunny bar has 12 squares. The cloudy bar has 7. Sunny days were most common; cloudy days were fewest. To find how many more, count from 7 up to 12:

There were 5 more sunny days. A taller bar shows more days. It does not show how hot each day was.

Compare temperature readings

Here are one week's noon readings: Monday 52°F, Tuesday 58°F, Wednesday 47°F, Thursday 45°F, Friday 55°F.

Find the biggest number: 58°F, on Tuesday. Find the smallest: 45°F, on Thursday. To find the difference, count up 10 from 45 to 55, then 3 more to 58.

Tuesday was 13 degrees warmer than Thursday. "Warmest" names the biggest reading; "how much warmer" asks for the gap between readings.

Your diary can show more than separate days. Some changes happen again and again. A pattern is a change or event that repeats in a similar way.

Compare morning and afternoon

A class took readings at 9 a.m. and 2 p.m.:

Look across each row. Every afternoon number is larger. These records show a pattern of warmer afternoons. Mornings are usually cooler than afternoons.

"Usually" matters here. A storm or cold wind can cool an afternoon. One cooler afternoon can fit among many warmer ones. Keep recording to see how often the pattern happens.

Look over more than one month

For seasonal patterns, compare different months and years. One class counted 9 sunny days in January and 13 in May. May had 4 more sunny days. January also had snow; May had none in those records.

That tells what happened that year. Compare January and May in other years to find out whether it keeps happening. A week can show a daily pattern, but it cannot show a whole year's seasonal changes.

Two rainy Mondays do not mean Mondays cause rain. The weather does not follow the names of weekdays. Look for a repeated change supported by many observations.

Make and check a prediction

A prediction is a careful guess about what will happen. You use facts you already know. After recording snowy Januaries, you might predict "Next January will have snowy days."

Keep the new records and check your prediction. A prediction can be wrong, even when you used a sensible pattern.

A weather forecast is a prediction made by weather scientists called meteorologists. They collect weather measurements and use satellites, radar, and computers. Tomorrow's forecast is usually more accurate than next week's.

A forecast tells what to expect. Your diary tells what you observed. Put them side by side: "Rain was forecast. We recorded rain at noon." You can then compare the prediction with what happened.

A season is a part of the year with its usual weather and daylight. The four seasons are spring, summer, fall, and winter. Fall is also called autumn.

Follow the repeating order

Say the seasons in order: spring, summer, fall, winter. After winter comes spring again. This repeating round is a cycle. There is no last season that stops the pattern.

Each season lasts about 3 months. Four groups of 3 months make the year's 12 months.

Match the months

US weather scientists group whole months this way:

To find a season using this table, first find the month. July 4 is in July. July belongs to summer. February 14 is in February, so it belongs to winter. Winter crosses the end of one year and the start of the next.

Read calendar start dates

Many calendars mark a different first day for each season:

• Spring starts around March 20.
• Summer starts around June 21.
• Fall starts around September 22.
• Winter starts around December 21.

These dates and the whole-month groups are two ways to mark seasons. Weather scientists count all of March as spring. A calendar still marks most of March as winter. When you use a chart or calendar, check which grouping it shows.

Look for changes around you

A date does not switch the weather all at once. Seasons change slowly, even though weather can change quickly from day to day. A warm winter afternoon is still in winter. A cold spring morning is still in spring.

Look for several clues: weather, daylight, plants and animals, and what people wear or do. A tree's new buds and longer evenings together can tell more than one warm day.

Season months depend on where you live. In Australia and New Zealand, December, January, and February are summer. June, July, and August are winter there.

You might wear a coat on one spring day and a sweater on another. Usual weather means the weather that happens most often over many days and years. One day's weather can be different.

Compare the seasons

Spring often brings showers. Early spring can still bring a snowy day. Many places have summer thunderstorms. In places with cold winters, the first frost often arrives in fall.

Winter does not bring snow everywhere. Minnesota can have snow-covered ground for weeks. Southern Florida usually has warm winter days, and snow is very rare there. Both places still have winter.

Notice which way things change

An April afternoon and an October afternoon could both be 60°F. The number alone does not tell you which season it is. Look at the changes around that day.

Through spring, weeks become warmer and daylight grows longer. Through fall, weeks become cooler and daylight grows shorter. You can see those directions of change in a diary kept over months.

Use many readings

Here are example noon temperatures:

Find the warmest January reading: 33°F. Find the coolest June reading: 75°F. Even the coolest June reading is warmer than the warmest January reading. Every row also shows a warmer June day.

These records are fair to compare because they were all taken at noon. Mixing winter afternoons with summer mornings would also mix times of day.

For a stronger picture, gather more days from each season. Compare the same months in other years too. A single unusually warm winter day could hide the usual difference if it were your only record.

A tree can help you watch the year pass. Its leaves and branches change slowly. Animals and people change what they do as the seasons change too.

Watch one tree

Many maples and birches grow buds and new leaves in spring. Their leaves are full and green in summer. In fall, leaves change color and drop. Winter leaves bare branches.

Evergreen trees, such as pines, stay green through winter. So a green tree in January does not mean it is summer. Look at what kind of tree you are watching.

Flowers often bloom in spring and summer. Fruits and seeds ripen in summer and fall. People pick apples and pumpkins in fall. Many plants rest during winter; some die back to their roots and grow again in spring.

Follow animals' changes

Some birds fly to warmer places in fall and return in spring. This long seasonal trip is migration. Many monarch butterflies travel from the United States and Canada to Mexico in fall.

Other animals stay nearby. A woodchuck may hibernate in winter. Its body slows greatly: heartbeat and breathing become very slow. It uses very little energy. It can wake for short times. Hibernation is different from an ordinary night's sleep.

Some bats hibernate too. Bears spend much of winter resting in dens.

The hare's changing colors help it hide among snow or plants. A squirrel's stored food helps it eat when winter food is harder to find.

Look for spring activity

Spring and early summer bring many ducklings, fawns, bees, and butterflies. Animals that were out of sight in winter have not all died. Some migrated, hibernated, or hid. Many insects spent winter as eggs or tucked into soil or bark.

Notice what people do

People change clothes, games, and work through the year. Cold weather brings coats, boots, and home heating. Warm weather brings lighter clothes and swimming. Farmers often plant in spring and harvest in summer or fall.

Pick one nearby plant to record each month. A small drawing of its buds, leaves, or bare branches gives you another kind of seasonal record.

A whole day lasts 24 hours. Part is daytime, and part is nighttime. Daylight, or day length, runs from sunrise to sunset.

Find the two times

Sunrise is when the Sun first appears at the sky's edge. Sunset is when it disappears in the evening. Ask a grown-up to help find these times for your town. A weather app, website, newspaper, or calendar may list them.

The sky starts getting light before sunrise. It stays a little light after sunset. The morning's soft light is called dawn; the evening's is called dusk. The listed sunrise and sunset times give you clear endpoints for counting daylight.

Never look straight at the Sun, even with sunglasses. It can hurt your eyes. Watch the sky's brightness or use the listed times.

Count through noon

On December 21 in Chicago, sunrise is about 7:15 a.m. Sunset is about 4:20 p.m. For a simple count, use about 7 in the morning to about 4 in the afternoon.

1. Count from 7 in the morning to noon: 5 hours.
2. Count from noon to 4 in the afternoon: 4 hours.
3. Put the parts together.

That is about 9 hours of daylight. We rounded the clock times, so the answer is about 9, not exactly 9.

Compare summer daylight

On June 21, Chicago's sunrise is about 5:15 a.m. Sunset is about 8:30 p.m. Count from about 5 to noon: 7 hours. From noon to about 8 in the evening is 8 more.

That gives about 15 daylight hours. The June daylight lasts much longer than the December daylight.

Compare light and dark

You can also check at one clock time in different months. At 5:30 p.m., it may be dark in December but light in April. Write both observations for the same place. They help show how daylight changes through the year.

A longer daytime does not make the whole day longer. Daytime and nighttime still total 24 hours. As daytime grows, nighttime shrinks.

Have you noticed summer evenings staying light longer? Daylight changes through the year in a repeating pattern. In the United States, summer has the longest days and winter the shortest.

Find the longest and shortest days

The most daylight comes around June 21, the calendar start of summer. The least comes around December 21, the calendar start of winter.

Chicago has about 15 hours of daylight in June and about 9 in December. Find the difference:

That is about 6 extra hours of daylight on the longest day.

Around March 20 and September 22, daytime and nighttime are nearly equal. Chicago has a little over 12 hours of daylight then. "Nearly" means close; it does not mean exactly the same.

Follow the change between them

From December toward June, days grow longer. From June toward December, they grow shorter. The change is small each day. In March, Chicago gains about 3 minutes a day, or about 20 minutes in a week.

Near the longest and shortest days, day length changes very little from one day to the next. You need records spread across weeks to notice much difference.

Long daylight comes with summer warmth. But the longest day is not usually the hottest day. In most of the country, the hottest weeks arrive in July and August. The coldest weeks usually come in January, after the shortest day.

Compare places

Anchorage's daylight changes much more. In Australia and New Zealand, December brings the longest days. June brings the shortest, matching their summer and winter.

Notice a clock change

Most US clocks move an hour forward in March and back in November. Sunrise and sunset then move on the clock together. Moving both times by one hour does not add or remove an hour between them. Daylight keeps changing slowly through the year.

The sky outside tells you what is happening now. A forecast helps you plan for later. Check it with a grown-up before choosing clothes or an outdoor activity.

Read the symbols and temperatures

A sun symbol means sunny weather. A cloud with drops means rain. Check when each symbol applies: morning, afternoon, or night.

The high is the warmest temperature expected that day. The low is the coolest expected overnight, from evening to the next morning. Tonight's low does not tell you this morning's exact temperature.

Try a forecast with afternoon rain and a high of 45°F. Tonight's low is 30°F.

1. Today's warmest temperature is still cool. Choose a warm jacket.
2. Afternoon rain calls for a raincoat or umbrella and boots.
3. Tonight is below freezing. For time outside after dark, add a winter coat, hat, and gloves.
4. Check the actual morning temperature with a grown-up before dressing for school.

Choose layers

Layers are clothes worn over one another, such as a T-shirt, sweater, and coat. Air between them helps hold warmth. Take one off if you get warm; put one on if you get cold.

Here is a simple clothes guide. Adjust it for how warm or cold you feel.

Plan for wet and windy weather

Waterproof clothes keep rain from soaking through. A rain jacket and boots help keep you dry. Wet socks and gloves cool you quickly, so change them when you come inside.

Cold wind can make you feel colder than the thermometer number. Cover your head, ears, and neck, and choose a jacket that blocks wind.

Keep another plan ready

Rain might move a picnic indoors. A storm might mean indoor recess. Bring an extra layer or raincoat if the forecast is unsure.

Weather can change your feelings too. You might feel cozy in rain or tired in heat. Your friend might feel differently. Tell a grown-up how you feel when deciding whether to change clothes or plans.

Sunny, hot, and icy days need different kinds of care. You can notice how your body feels and tell a grown-up when you need help.

Protect your skin in the Sun

The Sun gives off UV rays that can burn skin. Clouds let many of these rays through. A cool or cloudy day can still give you sunburn. Rays are strongest around the middle of the day.

Choose shade, covering clothes, a wide-brimmed hat, and sunglasses. Ask a grown-up to help apply sunscreen with SPF 15 or higher. Put more on about every 2 hours outside and after swimming or heavy sweating.

Stay cool in heat

Drink water often, before you feel very thirsty. Wear light-colored, loose clothes. Rest in shade and play more gently during the hottest hours.

If you feel dizzy, sick, unusually tired, or have a headache, stop playing. Very hot, red skin is another warning sign. Move to a cool place, drink water, and tell a grown-up right away.

Never stay or play in a parked car. The inside can become much hotter than the air outside very quickly.

Keep warm in cold weather

Wear layers and cover your ears, nose, fingers, and toes. A hat, mittens, scarf, warm socks, and waterproof boots help.

Very cold weather can freeze and damage skin. This injury is frostbite. If skin hurts, tingles, feels numb, or looks white or grayish, go inside and tell a grown-up right away. Feeling numb means you cannot feel that part normally.

Walk carefully on ice

Take small, flat steps on icy paths. Hold railings where you can. Stay off frozen ponds, rivers, and lakes. Ice can look strong and still break under you.

Short winter days can mean walking near roads in the dark. Bright or reflective clothes help drivers see you. Reflective material shines back when light hits it. Stay away from working snowplows, and keep snow forts away from the street.

Some weather can hurt people or damage things. This is severe weather. A weather warning tells you danger is coming or already happening. Listen to grown-ups and follow your home or school plan.

When you hear thunder

Thunder means lightning is close enough to hurt you. Go into a sturdy building, such as a house or school. An enclosed car with a hard metal roof and closed windows is another safe shelter. A tree, tent, or open picnic shelter does not keep lightning away.

Stay inside for 30 minutes after the last thunder. A new rumble starts the wait again. If it has been 20 quiet minutes and thunder sounds again, begin a new 30-minute wait.

Indoors, stay away from windows. Wait to take a bath or shower until the storm has passed.

Keep away from floodwater

Do not walk, ride, or play in floodwater. Moving water just 6 inches deep can knock an adult down. Water can also hide holes and sharp objects. Turn back and tell a grown-up when water covers your route.

Watch for storm damage

Strong wind can bring down branches, trees, and power lines. Keep away from them. Never touch a fallen power line or anything touching it. It may still carry electricity. Tell a grown-up right away.

Go to your tornado safe place

A tornado warning means go straight to your safe place with a grown-up. A basement is a good choice. Without one, use a small room with no windows in the middle of the lowest floor. An inside hallway, bathroom, or closet may fit that plan.

Crouch down and cover your head with your arms or a helmet. Stay there and follow the grown-up's directions.

Practice the plan

Learn your safe place at home and at school before a storm. During a drill, practice the route with a grown-up. A drill lets you learn while everyone has time to help.

Help pack an emergency kit with a flashlight, water, and snacks. Knowing where to go and what to do gives you a clear job if a warning comes.