We currently plot temperatures on Google maps. (http://www.temperatur.nu/kartav3.html)
At certain predefined zoom levels we want an transparent overlay similar to a heatmap instead of the plotted temperatures.. See http://www.wxtiles.com/ for an example. The overlay must be more detailed and more nice looking than wxtiles.com version.
Data source is an xml-file with temperatures and coordinates.
The finished temperature overlay must be implemented on our current site - our current Google maps (api v3) solution must be rewritten/modified to support the temperature overlay.