dude, was exited to suddenly get rain after your last update, nice. but it totally f*cks with solar power generation and even day-night cycles... suddenly the solar power period is just as short as the night time, ramps up and down inconsistently and remains like that after turning off rain in the options or even when removing this mod. WHAT DID YOU DO??? i fear for my save... :(

this is what i mean: https://imgur.com/a/7nsay2y

what is to be done?

Hey, sorry to hear about that!

The mod temporarily changes the Nauvis surface parameters such as dusk, dawn, evening, and morning times - to make the world darker during rain. This also affects solar power generation (as shown in the picture below)

Normally, these values are automatically restored to their default state when the rain stops. However, if you remove the mod while it's raining, the parameters remain in their current (possibly darkened) state.

In addition, once the mod is installed, it saves the current parameters as the "default" ones. So, I guess the problematic scenario looks like this:
1. Install the mod
2. It starts raining - parameters get darkened
3. Save the game
4. Remove the mod
5. Load the game and save it again
6. Reinstall the mod
7. The mod saves the already darkened parameters as defaults, so disabling rain later will just restore those darkened values

I've added a few workarounds in version 0.9.2. You just need to install this version and then disable rain in the settings.
If you've already disabled rain, then enable it again, return to the game for a moment, and disable rain once more. That should fix the issue

Another way is to install https://mods.factorio.com/mod/diurnal-dynamics
and set the default options:
- dusk = 0.25
- evening = 0.45
- morning = 0.55
- dawn = 0.75

brother, premium answer - thank you! maybe add a little hint/warning to your description so folks are prepared for these rain effects? if one relied on solar+accumulators alone, they should be known before installing this. :P
thanx again, may use this on my next play-through then.... rain! love it!

You're welcome!
I got another report related to the day-night cycle. I didn’t realize that this feature could cause such unexpected side effects. So I decided to remove the feature that changes day-night cycle parameters until I come up with a better approach. For now, the rain no longer affects any daytime settings