Zero. First time in 100 years that's happened. It may have significant climactic meaning.
In the past 1000 years, three previous such events -- the Dalton, Maunder, and Spörer Minimums, have all led to rapid cooling. One was large enough to be called a "mini ice age". For a society dependent on agriculture, cold is more damaging than heat. The growing season shortens, yields drop, and the occurrence of crop-destroying frosts increases.Global warming theory skeptics claim that known global warming is caused by changes in solar flux, not humanogenic gases. Changes in sunspot activity don't seem to have anything to do with that argument, though: sunspots don't correlate with changes in total solar radiance. Instead, they seem to relate to cloud formation. And the mechanisms appear to be complex, controversial, and poorly understood.
Whatever the cause, this has been one of the mildest Augusts in recent memory here in the US Northeast. Daytime temps in the 80s, nighttime temps in the 60s, generally low humidity. The last time it was this mild in the summer was in the first year or two after the eruption of Mt. Pinatubo in 1991 threw a couple of cubic miles of terra firma into the atmosphere and dropped temperatures around the world.
2008, if trends continue, will be the coldest year since 2000.
Does this mean we're in for an exceptionally harsh winter? After a couple of bad winters in the 90s, I bought a snowblower, which has seen increasingly little use: last year, I had to use it *once*. This year, though, it may earn its keep.