As others have stated, it really, really depends on where you are.
If one gets off the road system in Alaska and/or into an area without breeze, they can be pretty bad.....and while "mosquitoes" is the common designation, it's really "bugs" that can be bad; mosquitoes, gnats, black sox, etc.
I thought I had a picture, but can't find it, of the ole PA-12 from last summer after taking off from a strip alongside a swamp near Talkeetna. My beloved blue leading edges were substantially gunked up with dead, black bugs and the prop had nasty yellow and green streaks.
Bugs do seem to vary from year-to-year, but (based on a few decades of living in AK), I'd be prepared for bugs if you plan on going outside of the developed areas.
Buy or make a mosquito control kit. It's a block of wood and a mallet. When the mosquito lands on the block you whack it with the mallet. The hard part is getting the mosquito on the block and to sit still long enough for you to whack it.
I use a similar control method, though my husband sometimes objects to standing in for the block of wood...
" Not every mind that wanders is lost. " With apologies toJ.R.R. Tolkien
I bet they will be bad this spring we have over a 100 inches of snow in Anchorage which is double the normal, which means lots of puddles for them to breed in. we have three mosquito seasons, the big ones come out in spring, the smaller ones in the early summer, and the second round of big ones in the fall.
I was in Kotzebue(33 miles north of the circle on the west coast) about 7 years ago for work and I remember stepping out the truck and the mosquitos rose off the tundra and formed a black cloud and tried to eat us, the 100% deet kept them at bay for a while...
We have alot of gnat type bugs in parts of the state too, over in Tok the gnats swarming your head are far worse than the mosquitos, The only zone clear of bugs in my camp is within a few feet of the bug zapper, they seem to avoid it rather than being attracted to it like they should be.
Wow! A lot of you were in Alaska in 2009. We were, too!! It was a gorgeous summer wasn't it? We'll add that we had no problem with mosquitoes. It all depends on the weather. We lucked out with a warm, dry summer. Hope you do, also.
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel