I was at Blancaneaux again about three weeks ago. I stayed in one of the villas, and it was fantastic.
Being in the Mountain Pine Ridge at about 2,000 or 2,500 feet elevation, Blancaneaux is much cooler and less humid than most other parts of Cayo, and there usually aren't many mosquitoes or other bugs. Once in a while I hear from people who stayed at Blancaneaux and who were bothered by mosquitoes, but I've never been, and I have stayed there a couple of times in August.
Still, you're in the sub-tropics in August, so don't expect that it will be like New Hampshire in November. It's going to be pretty warm, as will be all of Belize. Blancaneaux has no air-conditioning in any of its units.
Belize books and publications by Lan Sluder:
Belize First Magazine (http://www.belizefirst.com
Fodor's Belize & Guatemala Guide (new 4th edition coming this summer)
Adapter Kit: Belize (the first and only comprehensive guide to living, retiring, working and investing in Belize -- a best-seller on Amazon.com)
San Pedro Cool (the first and only visitor guide to Ambergris Caye)
Belize First Guide to Mainland Belize
UpClose Central America
Belize Book of Lists