This script changes a rainy landscape to a sunny one.
Copy it into the scripts folder from GIMP, you will find it then under Filters -> Light and Shadow -> Sunny Landscape:http://docs.gimp.org/2.6/en/install-script-fu.html
If you like it, hug someone.
To fix burned out or white skies by adding clouds and a blue sky gradient (using a threshold mask).
Guide to Using the Blue Sky & Clouds Script
Unless otherwise noted, the rights for the individual plugins are with their respective authors. Logo image by Jakub Steiner.