They are around, but I don't see more than usual... at least not in my experience. For instance, I didn't see any around Franconia Notch. But I am swarmed by them on the local trails that are near water.
That reminds me of some funny deer fly anecdotes from this summer:
1) I ride my bike through some woods paths and dirt roads. The deer flies provide plenty of incentive to keep up the pace. If you ride fast enough, the rough little buggers bounce off your arms, legs, and face. Thud. Thud. It's almost satisfying... until one of them bites through your lycra and into your butt. Ouch.
Anyway, I was riding up a dirt road as fast as my body could take me, swatting the little things off my posterior when I glanced behind me. There were a cloud of deer flies drafting me! I kept moving fast until I got onto pavement, and kicked up the speed a notch or two. There were still deer flies behind me. Some had taken to landing on my bike (handlebars, seat post, rack, etc...).
While flailing at these little hitchhikers, I kept accelerating. Eventually I got to a downhill section and lost them. Nasty, and tenacious, little buggers!
2) While on one of these mad dashes through the deer fly badlands, I saw movement ahead. Running towards me was a guy jogging. Shorts. No shirt. No hat. I didn't notice any swatting. The guy must have been superman, or had just taken a bath in DEET.
3) Once I stopped to fix my bike in the middle of these deer fly infested wetlands. I stopped and they immediately clouded out the sun (well, it was low by then anyway). Swatting like a madman, I put some thought into somehow harnessing the flies to get me home instead of pedal power. Then as I focused on the bike, the flies went away. When I was done, I started riding and was instantly surrounded by them, the ride punctuated by the thud, thud of flies bouncing off me.
My takeaway - it seems like they are attracted to motion.
Anyway, I'll take deer flies over deer ticks any day.
