Wednesday, September 12, 2012

Today Marks The End...

...of average highs of at least 80 degrees in Philadelphia until June 4th.

Yep, today's the last day of "normal" highs of 80 degrees in the Delaware Valley until next June.  The slow decline of temperatures is about to become a more rapid slope of decline.

The good news is that reality and forecasts will keep us at or above 80 for the next few days, so there's little need to worry about coats and gloves, at least for a little while.

However, our average highs are starting to slip...and they will slip a fair bit quicker over the coming two months.  It will take just 26 days for our average high to drop from 80 to 70 and 58 days for the average high to drop from 80 to 60.  By November 7th, our average high will be in the 50's and stay below 60 degrees until April 4th.

Despite the gradual fall of what's considered "normal", we can theoretically reach 80 degrees until November 15th.  Our latest 80 on record in Philadelphia was on that date in 1993.   Also, over the last seven years we have hit 80 degrees at least once in the month of October, with the average "last 80" of the last seven years falling on October 11th.

Once we surpass our last 80 for the year, the earlier date on record of 80 degrees is March 8th, a record set in 2000.