(Note that the map isn't for April, it's for November 2001-April 2002). And why average over 6 months at all? Is this how they presented the data in the past? Just show us the data for each month and let us draw our own conclusions.
We had a very mild winter in Florida, but this spring was brutally cold (comparitively speaking).
Here in Detroit, according to PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6), the average monthly temperature has been 51.3 Deg. F. (6.5 Deg. F. below normal). Moreover there have so far been 270 heating degree days (heating degrees are the total number of degrees that the average temperature was below 65 Deg. F.), this is 83 more heating degree days than normal. The seasonal total of heating degree days thus far is 5496 (979 heating degree days below normal). Clearly May has been somewhat cooler than normal, but the entire season has not been as cool as normal. Furthermore, no cooling degree days have been logged for May so far (19 cooling degree days less than normal), and the 30 cooling degree days logged thusfar for the season are 5 more than normal.
Let me know where you live, I'll supply objective information pertaining to how cool it has not really been contrary to your feelings.
I've been trained as a weather specialist and that requires dealing with scientific facts, feelings and opinions that matter more than the facts do to a liberal.