If you’re playing ATM 9 (or between 7 and 9), Occultism and EvilCraft have methods of controlling the weather. Occultism has Dry, Rainy, Thunderstorm and even Time so Day or Night. Evilcraft with the Environmental Accumulator (your own or a charged one out about) can make a “potion” that you throw and it become the weather you want. Of the 2, Occultisms is easier to do.
https://www.reddit.com/r/allthemods/comments/19b3l79/is_it_possible_to_control_weather/

