In the mid-latitudes (25, 30 degrees or so), the daily reduction in insolation and longer night time radiation losses, would work against any significant lengthening of the "at risk" season for Cat 3+ hurricanes. Warmer water (no serious storms in the GoM in 2006 and so far in 2007) will likely add several days/a week to the at risk period.

A comparable argument can be made for other sources of heating.

Best Hopes,

Alan

IIRC the rhyme I learnt while sailing in the carribean was:

June too soon,
July stand by,
August you must,
September remember,
October all over.

Recent history would suggest this needs to be shunted forward at least one month.