This photo was taken at night, as you might suspect, using 7 individual exposures at 1/2 increments for a typical HDR (High Dynamic Range) scenario.  HDR simply put, means you take the first photo so it's nearly dark to capture all of the shadows, and the last photo so it's almost completely washed out to catch all of the highlights.  The 5 photos in the middle, shot at different exposure levels, capture all of the mid-range colors of the image.  Once gathered, all of the images were combined using Photomatix Pro software and presto-chango you have an HDR photograph.  I would like to say this photo was completed on my first or second attempt.   Not so.  I like to tell myself that trial and error is part of my workflow process, not an indication of incompetence.  This may have been the 10+ attempt to get it right, it's all a blur right now.

And for artistic reasons only, that seemed appropriate at the time, both the rain and the rainbow were added in post production using OnOne Effects software.Excellent software, reasonably priced now compared to other products, and works as advertised.Everything else in the photo is "as shot" with no enhancements other than HDR.