The ratings don't factor in weather, or hills, or tight fairways, or anything else. Ratings just look at the current ratings of all the propagators and the scores of all the propagators, and new ratings are calculated off the averages.
The ratings automatically take these factors into account via the scores that the propagators shoot. You can't break out how much the wind versus rain versus tight fairways specifically affect the scores. But all of those effects are rolled up into the socres the players shoot.