I'd like to share a mod I've made to replace the default weather.
The idea was to simulate a typical mid spring/fall day weather and bring back some of the atmosphere pre 0.8 patch.
Mod looks good at any given time of day but you'll probably find it looking best at around 9 and 17 hours.
Backup your files and extract DWM to Steam\SteamApps\common\assettocorsa\system\cfg
A typical mid spring/fall day.