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Build Your Own Weather Station Build Your Own Weather Station

“I believe there is a train under here somewhere!”

Standing tall on North Dakota snow. A March blizzard nearly buried utility poles. 

Caption jokingly read “I believe there is a train under here somewhere!” 

Courtesy Dr. Herbert Kroehl, NGDC

Every year, thousands of lives and millions of dollars are saved by severe 

weather warnings from the National Weather Service. From its earliest 

beginnings (on February 9th, 1870), the primary mission of the National 

Weather Service has been to protect life and property by providing information about dangerous weather conditions. Originally, the National Weather 

Service was called “The Division of Telegrams and Reports for the Benefi t of 

Commerce” and was part of the U.S. Army. Later, its name was shortened to 

the Weather Bureau and it became part of the Department of Agriculture, 

then the Department of Commerce. 

The fi rst “weathermen” were “observing-sergeants” of the Army’s Signal 

Service Corps. Weather forecasting in those early years was based almost 

entirely on the assumption that the weather observed in one location on 

a particular day would move to downwind locations on following days. 

Today, satellites, computers, and a variety of scientifi c instruments are 

added to this basic assumption to make accurate weather predictions 

and provide warnings about dangerous weather. 

Here’s how you can make your own weather observation station!

“I believe there is a train under here somewhere!”

What You Will Do Build six instruments that you can use to make 

scientific measurements of your local weather
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What You Will Need

r Five paper cups - Three ounce size

r Two straight plastic soda straws

r Straight pin

r Paper punch

r Stapler

r Sharp pencil with eraser

r Felt tip marker

r Watch or timer

Warning

Be careful with the straight pin!

How to Do It:

1. Using a paper punch, punch a hole in four 

paper cups about 1/2-inch below the rim of 

the cups.

2. Punch four equally spaced holes in a fi fth 

paper cup about 1/4-inch below the rim, and 

a fi fth hole in the center of the bottom of the 

cup (you will probably need to use the pencil 

to make the hole in the bottom).

3. Push a soda straw through the hole in one 

of the fi rst four cups. Flatten the end of the 

straw and staple it to the side of the cup 

opposite the hole. Repeat this step with the 

other straw and another of the fi rst four 

cups.

4. Slide one of the cup and straw assemblies 

through two opposite holes in the side of the 

fi fth cup. Push another one-hole cup onto 

the straw, and turn this cup so that the open 

ends of the two cups on the straw face in 

opposite directions. Flatten the end of the 

straw, and staple it to the side of the second cup. Measure the distance between the 

centers of the two cups. This is the diameter 

of your anemometer.

Build an Anemometer to Measure Wind Speed

3 oz. paper cup

Straw

Pencil

Straight pin
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5. Repeat Step 4 with the remaining cup and 

straw assembly and the remaining one-hole 

cup. Before stapling the end of the straw to 

the last cup, turn the cups so that the open 

end of each cup faces the closed end of the 

next cup.

6. Adjust the cup and straw assemblies so that 

they are centered inside the fi fth cup. Push 

the straight pin through the two straws 

where they intersect.

7. Push the eraser end of the pencil through the 

hole in the bottom of the fi fth cup, and push 

the straight pin into the eraser as far as it 

will go. Your anemometer is ready to use!

8. To use the anemometer, hold the pencil 

vertically in a wind, and count the number 

of revolutions per minute (use the felt tip 

marker to make a mark on one cup so that 

you can easily see when the cup has travelled through one complete revolution). To 

convert revolutions per minute (rpm) into 

approximate wind speed:

a. Multiply rpm by the diameter (in inches) of 

your anemometer (measured in Step 4) 

b. Multiply the result by 0.003. This is the 

approximate wind speed in miles per hour. 

 This calculation does not give exact wind 

speed, because drag, friction, and other 

forces also aff ect the speed at which your 

anemometer rotates. 

Finished Anemometer

Anemometer 
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Build a Weather Vane to Find Wind Direction

What You Will Need

r Broomstick or long wooden dowel, about one 

inch diameter

r Aluminum baking dish, about six inches x nine 

inches

r Wood stick, about 3/4 inch square and 12 

inches long

r Nail, about one inch long

r Metal washer with a hole slightly larger than 

the nail

r Duct tape

r Small saw or serrated knife

r Scissors strong enough to cut the aluminum 

baking dish

r Ruler or tape measure

r Silicone or other glue that will stick to aluminum

r Leather gloves

r (Optional) Hand drill, and small drill bit 

slightly larger than the nail

Warning

Be careful of the sharp edges on the pieces of cut 

aluminum! Use gloves to protect your hands until 

the edges are taped.

Mark this spot on the upper surface of the 

stick, and drive a nail through the marked 

spot. Be careful: if the nail is too big, the 

stick will probably split. To avoid this, drill a 

hole slightly larger than the nail through the 

marked spot. You may need an adult to help 

with the drilling.

3. Cut the head and tail pieces of the Weather 

Vane from the aluminum baking dish using 

the pattern as a guide. Be Careful—The 

Edges Are Sharp! Use duct tape to cover the 

sharp edges.

How to Do It

1. Use the saw or serrated knife to cut a notch 

about 1/2-inch deep into each end of the 

wood stick. The notches should be parallel 

(see drawing on page 65).

2. Rotate the stick so that the two slots are vertical. Use the ruler or tape measure to find the 

exact center of the wood stick. 

tail

head
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4. Fit the head piece into one of the slots in 

the wood stick and fi t the tail piece into the 

other slot. Glue the head and tail pieces into 

place and allow the glue to dry.

5. Attach the Weather Vane to the broomstick or 

dowel, by placing the washer on one end of 

the dowel and hammering the nail through 

the wooden stick into the dowel. 

 Be sure the stick still moves freely around the 

nail. 

6. Mount your Weather Vane outside where there 

are no nearby obstructions to block the wind. 

Try to get the dowel as high as you can while 

still keeping it steady and secure. 

 Winds are named according to the direction 

from which the wind is blowing, so a “north 

wind” is blowing from the north. The head of 

the Weather Vane will point to the direction 

from which the wind is blowing. 

head

tail

nail

dowel

washer

broom or long 

wooden dowel

Finished Weather Vane
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Build a Barometer for Measuring Atmospheric Pressure

What You Will Need

r 12-inch ruler

r Drinking glass or other container with sides 

tall enough to support the ruler

r Clear plastic drinking straw or piece of clear 

plastic tubing, about 12-inches long 

r Modeling clay or chewing gum

r Clear tape

r (Optional) Food coloring

How to Do It

1. Tape the plastic straw or plastic tubing to the 

ruler so that one end is lined up with the 

“1/2-inch” mark on the ruler.

2. Stand the ruler-tubing assembly upright in 

the glass (or other container), and tape the 

assembly to the top of the container.

3. Fill the container about 3/4-full of water. If 

you want colored water, fi rst mix food coloring with the water in another container.

4. Use the modeling clay or chewing gum (you’ll 

have to chew it until it is soft enough) to plug 

the end of the straw or plastic tubing near 

the top of the ruler.

5. Carefully pour out some of the water so the 

container is about half full. Be sure the lower 

end of the straw or tubing stays beneath the 

water surface while you do this! When you 

are fi nished, the water in the straw or tube 

should be higher than 

the water in the container. Your barometer 

is now fi nished. Since 

barometers are sensitive to minor changes 

in weather conditions, 

keep your barometer 

indoors for greatest 

accuracy.

6. Keep a daily record of 

the height of the water 

in the tube, using the 

scale on the ruler. 

The water level in the 

tube will rise and fall 

as atmospheric pressure changes. When 

atmospheric pressure 

increases, air presses on 

the surface of the water 

in the container causing 

the height of the water 

in the tube to rise. When atmospheric pressure decreases, there is less pressure on the 

surface of the water in the container so the 

height of the water in the tube falls. Decreasing atmospheric pressure usually indicates 

that a low pressure area is approaching, and 

this often brings clouds and rain. Increasing 

atmospheric pressure often indicates fair 

weather.

Finished Barometer

glass container

ruler

clear straw or 

plastic tubing

tape 

gum or clay

tape 
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Build a Screened Thermometer to Measure Air Temperature 

What You Will Need

r A wooden or plastic box, large enough to hold 

the thermometer and your hygrometer; see 

Step 1 under “How to Do It”

r Thermometer, about 0°F to 120°F

r White paint and paint brush

r Nails, screws, glue, or tape to attach the thermometer to the box

How to Do It

1. The wood or plastic box is supposed to protect 

your weather instruments from wind, rain, 

and direct sun, but still allow air to circulate so the instruments can get accurate 

readings. A box with a hinged lid that can 

be turned on its side is perfect. Turn the box 

on its side, and cut several slots near what is 

now the bottom of the box. Paint the outside 

of the box with white paint, and find a safe, 

shady outdoor location. The north side of 

buildings has the most shade. Try to find a 

location that is three to four feet above the 

ground.

2. Attach the thermometer to the back of the box 

with tape, glue, screws, or nails. The bulb of 

the thermometer should be about two inches 

above the bottom of the box.

Build a Hygrometer to Measure Humidity

What You Will Need

r Piece of wood or Styrofoam about nine inches 

long and four inches wide

r Flat piece of plastic, thin enough to cut with 

scissors; about three inches long and one 

inch wide (an old credit card or laminated 

luggage tag works well)

r Two small nails

r Three strands of human hair, about eight 

inches long

r Dime

r Glue

r Tape

r Hammer

r Scissors

How to Do It 

1. Cut the plastic into a pointer as shown on the 

pattern below.

2. Poke one of the nails through the pointer 

near the base of the triangle. Wiggle the nail 

around until the pointer moves freely and 

loosely around the nail.

3. Tape the dime onto the pointer near the tip of 

the triangle.

4. Glue the hair strands onto plastic between the 

nail hole and the dime.

5. Use a nail to fasten the pointer to the wood or 

Styrofoam base about 3/4 of the way down 

the side. Be sure the pointer can still turn 

freely on the nail.

6. Attach the other nail to the base about one 

inch from the top of the base, in line with the 

spot where the hair is glued to the pointer.

7. Pull the free ends of the hair tight so that the 

pointer is horizontal. Wrap the hair around 

Pointer Pattern
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0

5

10

15

-5

-10

-15

0

5

10

15

-5

-10

-15

the upper nail and glue to hold the hair in 

place.

8. Make a photocopy of the scale and cut it out. 

Glue the scale to the base so that the pointer 

is pointed to the “0” mark. Your hygrometer 

is fi nished!

9. Human hair will expand and lengthen when 

the air is moist, causing the pointer to move 

down. When the air is dry, the hair will 

contract and shorten, causing the pointer to 

move up. Use the scale to record the pointer’s position. Keep your hygrometer in a sheltered location. The box used for the screened 

thermometer is ideal.

Wood or Styrofoam

nail

nail dime

plastic pointer

Hair

Finished Hygrometer
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Build a Rain Gauge to Measure Rainfall

What You Need

r Straight-sided glass or plastic container, with 

a diameter of about two inches or less (such 

as an olive jar)

r Coat hanger or wire bent to make a holding 

rack (see picture)

r Measuring spoons: One teaspoon and 1/4 

teaspoon

r Hammer and nails to secure the rack

r Felt tip marker

How to Do It

1. Rain gauges measure the amount of rainfall 

in cubic inches. So your fi rst task is to make 

a scale for your container that shows how 

many cubic inches of water are in the container. One cubic inch of water is about 3 1/4 

teaspoons, so you can draw the scale on your 

container by measuring 3 1/4 teaspoons 

of water to your container, then drawing a 

short line at the level of the water. If you 

look closely, the top of the water will seem 

to be slightly curved and thickened. Draw 

your line so that it matches the bottom of the 

curved surface (which is called a meniscus). 

This line corresponds to a rainfall of one 

inch. 

2. Add another 3 1/4 teaspoons of water to the 

container and draw another line. The second 

line corresponds to a rainfall of two inches. 

3. Repeat Step 2 until you have at least fi ve 

marks on the container. This will be enough 

for most rain events; but you may want to 

add another line or two, just in case!

4. Find a location for your rain gauge where there 

is nothing overhead (such as trees or a building roof) that could direct water into or away 

from your gauge. The edge of a fence away 

from buildings is often a good spot. Another 

possibility is to attach your rain gauge to a 

broomstick driven 

into the ground 

in an open area. 

Be sure to record 

rainfall soon 

after a rain event 

to avoid false 

readings caused by 

evaporation. 

Empty your gauge after each reading, and you are 

ready for the next event!

This activity is adapted from Weather Scope: An Investigative 

Study of Weather and Climate:

http://www.k12science.org/curriculum/weatherproj2/en/

activity1.shtml.

glass container

Finished Rain Gauge

coat hanger or wire

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