Doing the requirements for the Weather merit badge helps Scouts learn about meteorology. They learn about weather hazards, high and low pressure systems, the science of weather, and the water cycle. They explore climates and the way humans alter their environment. They make a weather instrument and find out about careers related to weather.
Get the Weather Merit Badge pamphlet
Printable helps for requirements:
Printable requirements for Weather Merit Badge
Printable checkoff sheet for Weather Merit Badge
Printable note sheet for Weather Merit Badge
Printable checkoff sheet for all Scouts BSA merit badges
Investigate the causes and effects of meteorological phenomena with these related ideas and achievements:
Water Cycle Demonstration

This project will demonstrate the water cycle to scouts. This demonstration can be used with requirement 1 for the Weather belt loop for Cub Scouts or with requirement 6 for the Weather merit badge for Scouts BSA.
Wild Weather Adventure Game

This is a board game I came across recently on the NASA Space Place website. It is going to take a little time for you to print and prepare the materials, but I think this would be a hit at any weather themed scout meeting.
Printable Explanation of the Water Cycle

With all of the rain we've been having lately, this seems like a good time to post this aid to help explain the water cycle. I made this aid to help my Webelos when they were working on the Weather belt loop as a requirement for the Scientist activity badge. The material also fits in with the Weather merit badge.
Shoot! Scouts BSA Nova Award (Astronomy and Projectile Science) Helps and Documents

Shoot! is the Scouts BSA Nova Award for investigating astronomy and projectile science. To earn this award, Scouts must complete one of their science related merit badges and learn about related topics such as space, aviation, and weather. Scouts also visit a museum or build a catapult, pitching machine, or marble run.
Designed to Crunch Scouts BSA Nova Award (Mathematics) Helps and Documents

Designed to Crunch is the Scouts BSA Nova Award for mathematics. To earn this award, Scouts must complete one of their mathematics related merit badges and learn about related topics such as calculating horsepower, statistics for athletics events, and star counts.
Splash! Scouts BSA Nova Award (Science) Helps and Documents

Splash! is the Scouts BSA Nova Award for investigating water science. To earn this award, Scouts must complete one of their science related merit badges and learn about related topics such as pollution, health, water cycle, and waste treatment. Scouts also learn how water is processed and consumed.
Science Program Feature for Scouts BSA

The Science troop program feature encourages Scouts to ask and investigate questions about the world. They learn how to form a hypothesis and test it.
Make a Tornado in a Bottle

Tornadoes are destructive storms are caused by a vortex. You can use the classic “tornado in a bottle” demonstration to explain how a vortex forms. This demonstration goes well with a weather related activity or just for some STEM fun.