GeoLawWatch: Tracking Weather & Climate Legislation

Tracking weather modification, cloud seeding, and geoengineering bills in real time across the US.

Geoengineering Bills by State

Bill # Details Effective Status
2019 Regular Session
HJ40 Study of weather modification Passed
Montana House Joint Resolution 40 passed in 2019 directing a legislative study of weather modification laws to propose changes that would encourage increased use of cloud seeding technology for enhancing precipitation and water supplies. Last update
Wed 1 May 2019
  Note: Resolution filed with Secretary of State May 1 2019
2021 Regular Session
SB29 Revise weather modification and control laws Died in process
Montana Senate Bill 29 passed the Senate in 2021 but died in the House revising weather modification laws to streamline the licensing process mandate 100000 dollar liability insurance require environmental review and facilitate increased use of cloud seeding technology. Last update
Thu 29 Apr 2021
  Note: Passed Senate; rejected by House floor.
2025 Regular Session Session Adjourn Wed 30 Apr 2025
SB473 Prohibit weather modification. House Not Concurred
Montana Senate Bill 473 passed the Senate in March 2025. Still, it died in the House, prohibiting large-scale geoengineering practices such as stratospheric aerosol injection and solar radiation management, while explicitly protecting cloud seeding for agriculture and water management. Last update
Fri 23 May 2025
  Note: Survived Senate drama; died on House floor