fair up/fair off: Chiefly Southern U.S. (meteorology) To clear: They said it was going to fair off later on, but it didn't. YourDictionary
South Midland and Southern U.S. (of the weather) To clear:
It's supposed to fair off toward evening. Random House
Southern fair off and fair up, meaning "to become clear," were originally Northeastern terms and were brought to the South as settlement expanded southward and westward. They are now "regionalized to the South," according to Craig M. Carver, author of American Regional Dialects. These phrases may have prompted the coining of milding and milding down, noted respectively in Texas and Virginia by the Dictionary of American Regional English. AHD
Don't get so down on yourself, things will fair up.
: Improve: If bad weather or an unpleasant situation lets up, it stops or improves: When the rain lets up we'll go for a walk. COD
Don't get so down on yourself, things will let up.
ease up/ease off: To gradually stop or become less: At last the rain began to ease off. COD
Don't get so down on yourself, things will ease up.