This guide explains how to change the weather in Pokemon Sword and Shield. This is done by selecting specific dates in the Nintendo Switch Settings. It works because specific dates correspond to specific weather. This is extremely helpful when hunting for Pokemon. Every Pokemon appears only during certain weather conditions. By manipulating the weather you take the waiting time and guesswork out of it and can complete your Pokedex much faster!
How to Change Weather in Pokemon Sword & Shield: To change weather you must change the date in your console settings. The specific dates listed below each trigger a specific weather condition across all wild areas. To change weather: Press the Home-Button > System Settings > System > Date and Time.
Normal Weather – May 01, 2020
Overcast – March 01, 2020
Raining – October 01, 2020
Thunderstorm – November 01, 2020
Snowing – December 01, 2020
Snowstorm – February 01, 2020 – unlocks at some point midway through the game
Intense Sun – July 01, 2020
Sandstorm – April 01, 2020 – unlocks at some point midway through the game
Heavy Fog – June 01, 2020 – only after becoming champion (finished story)
There’s no need to close the game application. You can continue right where you left off without restarting, and the weather is changed instantly.
It’s worth noting that three weather conditions (Snowstorm, Sandstorm, Heavy Fog) are not available from the start. That’s because they make certain rare and more powerful Pokemon spawn that the game doesn’t want you to see until you’ve made more progress. After you’ve become champion and finished the main story, you will have access to all weather conditions.
How to Check Active Weather: Open the Town Map and press 
to see a weather map (refer to above icons if you are unsure what icon corresponds to which weather). If you put in the specified dates from above you will see it’s the same weather everywhere in all of the wild area. Some routes are not affected by this, but you can try changing the date manually until you get your desired weather condition for specific routes.
Note: Changing the date will also change the available Max Raids in the wild area.
That’s all the tricks to switch to any weather condition you want in Pokemon Sword and Shield, enjoy!
Thanks mate!