Games where rain.

DayZ SA.

Max Payne 2.

Witcher2 hat quite nice rain. There are also a couple of cool mods for Skyrim, making the rain awesome..

Dayz 2 :Chubby rain

heavy rain

Donkey Kong Country :D

Witcher 1

Sleeping Dogs. The rain gives this game the awsome exotic touch ;)

Tomb Raider

CLONK !!! :D

Remember the saga Clock Tower 1-2-3.
Haunting Ground.

I love the old Ps2,good memories.

Cold Fear.

Gone Home

Ugh!

·Far Cry 3.
·Metal Gear 2.
·Splinter Cell 3 Chaos Theory (if i remember well)

Have a nice day :)

Bad Rats, that game is so good it makes me rain tears.

left 4 dead 2 in some campaigns

Everquest

Gemini Rue

thats actually a very interesting question! I'm intruiged why you're asking.
Also, does risk of rain have rain? I don't remember.

You can do it on GTA 4, through a game editor mod so it always rains. (same thing for Minecraft)

I thought skyrim had rain, I'm not sure though.

Skyrim - altough there is more snowing than raining.
Terraria - it rains quite a lot.
Sims 2/3 Seasons
Dota 1 - you can type -weather rain and it will rain the whole match.
More which have already been mentioned anyway

Minecraft and Euro truck simulator

Finally remember the name: Silver there was a city Rain, where always rain :-D