Update: Niantic have fixed the issue with the dynamic weather system, and the weather system is back and running.
Previous story: The new weather feature in Pokemon Go is down and Niantic Support is already familiar with this problem and they are working on solving the problem as announced on their official Twitter account.
The weather system is something quite exciting in the game, because it allows particular Pokemon to get weather bonuses, depending on their type. The same goes for the Raid Bosses, which makes it difficult to overcome and catch.
The weather system in Pokemon Go adapts to players local weather patterns. The same time, Pokemon are getting weather bonuses, increased spawn rate, +25% Stardust on Type Catches (25/75/125) and extra 20% Type attack Strength.
At the moment, the weather feature is offline for all players and no one can’t take advantage of any of the aforementioned until Niantic fixes the issue, and I expect to see it up and running soon.
Niantic has written on their official Twitter account:
We’re currently investigating an issue which is preventing Trainers from experiencing the dynamic weather system in Pokémon GO. Thanks for your patience as we work on a fix. https://t.co/TYjuDDNL2Q
— Niantic Support (@NianticHelp) January 3, 2018
Until they fix the problem, feel free and check out Min and Max IV CP of Raid Bosses when normal and weather boosted, level 1 to 5 raids guide, and when to take advantage of catching Lvl 25 Raid Bosses instead of 20.