I have allergies as well and I would assume allergies acting up so early this year (in Portland) have to do with the heat these last couple weeks. It got up into the 90's last week, four days in a row. The news said Portland hasn't had 4 days of consecutive 90 degree weather (so early?) since 1997. I was doing just fine here until the last couple weeks, and now I am stuffy in the morning, clear up during the day, and start getting really stuffy around 8-8:30pm everynight... it's like clockwork.

I can't speak for the rest of the nation, but in Portland I would contribute this to the warmer, non-rainy weather we have been having so early in the spring/summer time.