ALEX Lesson Plan

How do clouds form?

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  This lesson provided by:  
Author:Bonnie Howard
System: Madison City
School: Madison Elementary School
The event this resource created for:ASTA
  General Lesson Information  
Lesson Plan ID: 34560


How do clouds form?


The lesson provides an overview of cloud formation. Cloud formation results when warm, humid air rises and cools, causing the water vapor in the air to condense and form clouds. In this lesson, students will conduct an activity that demonstrates how this occurs.

This lesson results from a collaboration between the Alabama State Department of Education and ASTA.

This lesson was modified from NASA series “Investigating the Climate System.  They can be freely downloaded at

 Associated Standards and Objectives 
Content Standard(s):
SC2015 (2015)
Grade: 6
Earth and Space Science
7 ) Use models to construct explanations of the various biogeochemical cycles of Earth (e.g., water, carbon, nitrogen) and the flow of energy that drives these processes.

Alabama Alternate Achievement Standards
AAS Standard:
SCI.AAS.6.7- Use a model to explain the water cycle, including evaporation, condensation, and precipitation; recognize that the sun provides the energy which drives the water cycle.

Local/National Standards:


Primary Learning Objective(s):

The students will use a model to construct an explanation for cloud formation. 

Additional Learning Objective(s):

 Preparation Information 

Total Duration:

61 to 90 Minutes

Materials and Resources:

safety goggles
clear plastic bottle with cap
enough water to wet the bottom of the bottle
incense stick (or you can use a paper match)


hot plate

Erlenmeyer flask (2)


rubber band

science journal

Technology Resources Needed:

Interactive whiteboard

internet connection

Student computer (for extension activity)


Background Water vapor; water in its invisible gaseous state, can be made to condense into the form of small cloud droplets. By adding particles such as the smoke enhances the process of water condensation and by squeezing the bottle then releasing it causes the drop in air pressure, which is like air rising to make a cloud. Squeezing the bottle increases the air pressure, like air sinking. This creates a cloud. Evaporation: Water evaporates. Why? The heat from the sun causes water to evaporate and become a vapor that rises up into the atmosphere to become a cloud. You can illustrate evaporation by boiling water in a pan over a hotplate so participants can see the vapor rising. Condensation: All air contains some water in vapor form. Usually, we can't see it but we know it is there by how wet or dry the air feels on our skin as well as our noses and mouths. As warm air rises, it carries water vapor with it. As the air continues to rise, the warm air cools and the pressure eventually decreases enough that the water vapor turns into liquid droplets. These droplets form or condense on smoke and dust particles in the air. The process of changing water vapor into liquid water is called condensation. Vapor turns into raindrops forming a cloud. Precipitation: As more and more droplets of water form into a cloud they start bumping into each other. Some of them stick together and grow to the size of a raindrop (> 1mm in diameter.) As more droplets form into raindrops they get very heavy and eventually fall out of the cloud when the updraft can no longer hold them as a cloud. The cloud bounces and shakes, or precipitates, releasing the droplets in the form of rain, hail, or snow.



As students enter the room have the following prompt written on the interactive whiteboard and ask them to take out their science journal and spend a few minutes generating ideas.

How do you think temperature, pressure or changes in volume are involved in cloud formation? 

Give students time to think about their responses and record their answers in their journal. After 3-4 minutes, have students turn and talk to their neighbors and formulate a response that represents the shared thinking of the people at their table. Bring the entire class back together and have each table group share out their collective ideas.

During their sharing, ask students to share ideas about how water vapor gets into the atmosphere and eventually forms clouds.  

To begin the demonstration, add 5 mL of tap water to the Erlenmeyer flask then place the balloon over the opening to seal the flask then place it on a hot plate.  Heat the water, but do not let it all boil away.  

Carefully remove the flask from the hot plate and ask students to share what they observe.  Have students explain to you why the balloon inflates by drawing on their prior learning from previous labs and investigations.

Repeat the procedure with a second Erlenmeyer flask but this time do not stretch the balloon over the opening until after you remove it from the hot plate. Place the flask into the ice water bath.  If performed correctly, the balloon should invert into the flask.  Again ask students what they think is happening. Relate this back to previous lessons on air pressure. 


Students receive lab materials listed in the Materials section.

Lab Procedure

1. Put on safety goggles.

2. Pour water into the 2L bottle, place the cap on, and shake for 30 seconds.

3.  Squeeze the bottle—

Ask the following questions.

  • What effect does this have on the environmental conditions inside the bottle?

Now release the pressure on the bottle.

  • What effect does this have on the environmental conditions inside the bottle?
  • Did a cloud form?

4. After the smoke from the incense or paper match is placed in your bottle, quickly place the cap on and then repeat Step 2.

  • This time, did the cloud appear when you squeezed or when you released the bottle?
  • What’s happening when you do this (i.e., what condition has been provided for clouds to form)? 

Explain to the students.  Even though we don't see them, water molecules are in the air all around us. These airborne water molecules are called water vapor. When the molecules are bouncing around in the atmosphere, they don't normally stick together.

Pumping the bottle forces the molecules to squeeze together or compress. Releasing the pressure allows the air to expand, and in doing so, the temperature of the air becomes cooler. This cooling process allows the molecules to stick together – or condense – more easily, forming tiny droplets. Clouds are nothing more than groups of tiny water droplets!Students


Students will share their observations with the whole class. 

Ask the participants to recap the entire experiment and discuss what happened in each step.

How was water vapor created? (Water in its invisible gaseous state, can be made to condense into the form of small cloud droplets.)

What happened when smoke was added to the bottle with vapor? (smoke provides the particles) What role does smoke play in creating a cloud in the sky? (By adding particles such as the smoke enhances the process of water condensation.)  

What is air pressure and how did you change the pressure in the bottle? What role does air pressure play in the creation of a cloud? (By squeezing the bottle causes the air pressure to drop. A cloud appeared when you released and disappears when you squeeze.)

Review the roles of vapor, smoke, and pressure in creating a cloud.  


Using knowledge gained from the experiment, students will provide a written explanation on how clouds form in the atmosphere. Each student will then draw their own illustration of cloud formation in their science journal. Students create an illustration to model the roles of vapor, smoke, and pressure in creating a cloud. 


Assessment Strategies

Assessment during this activity is formative to determine if students can use a model to construct an explanation for cloud formation. The teacher will observe student participation during the lab activity and review completed cloud formation illustration. 

A rubric can be used to assess participation in the lab activity. The rubric can be found on page 13 entitled rubric activity two on the following website 


Cloud seeding is a process by which particles are dispersed in the air in an attempt to increase the amount of precipitation in a particular area. Research the history and effectiveness of cloud seeding. Provide at least three examples where it has been used. In addition, provide three arguments for or against the use of cloud seeding


Ask students to write and/or illustrate what they did during this activity and what they learned from their participation in the activity.  

View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.