I found a mosquito map! Not that it makes you feel any better this time of year, but I thought it might be useful in planning trips.
Go to http://www.accuweather.com/en/us/detroi ... ast/348755. This one is for Detroit, MI. Unfortunately, it only lists about 7 or 8 towns, but that does not matter because there is also a national map shown. Just pick the nearest town and open up the main page for that city.
Then you need to click on the plus sign (red arrow) and scroll down to where it says "Mosquito Map" (green arrow) and click on it.
THis will add the mosquito forecast to that town, as shown by the yellow arrow.
Then, to get the national map, you need to scroll down and look on the right to see this:
I think I want to go back to California. Unfortunately, it really doesn't give you much of a forecast in terms of days out, but it is interesting.