With basic editing there isn't much you can do to improve this image for the time of day it was taken. I would love to see this image with the city darkened more to provide more of a silhouette feel. The detail in the city doesn't really add to the picture, as the lighting and colors on Mt. Rainier are wonderful.
Very well done! Capturing Rainier clearly from Seattle can be a challenge. I love that the Space Needle is so prominent in the foreground. I also like how the everything seems to get smaller from the Space Needle as it leads your eye to Mt. Rainier.