Tuesday, August 20, 2013

Summer Of 2013 To Be "Coolest" Since 2009

12 days are left in meteorological summer including today. Despite the good odds of additional 90 degree days later this week, it is looking like this summer shapes up as the "coolest" in Philadelphia since 2009.

The quotes around "coolest" are intentional since this summer will end up being above normal by about a degree and a half once the month is all said and done. However, compared to 2010-2012 this is the most tolerable summer we've had as far as temperatures are concerned overall.

And it will feature the fewest number of 90 degree days since 2009's tally of 15.  It's going to be really tough to get to 33 (2011's tally of 90 degree days) between now and season's end, regardless of how many 90 degree days we get this week.

2013 data through Sunday 8/18/2013.
Daily average based on monthly data for June-August in 2009-2012 and may not round perfectly.

Our summer's average high temperature through Sunday is 84.8, over two degrees below what we tallied in each of the last two summers. This more than makes up for the average low hanging out right near the mark of the last two years (68.8 is this year's tally so far).  The lower average high is due to the nice stretch of weather we had during most of the last four weeks but also due to additional cloud cover around the region, the latter of which was a driver in that record-setting streak of 70 degree nights we had last month.  Despite that 30 day streak where we couldn't get below 70, the average nighttime low this summer in Philadelphia is still lower than any year since 2009 and almost two degrees lower than 2010's average.

This August's low temperature has averaged out to 66.6 degrees, nearly four degrees lower than last year and cooler than 2009's average.

It's all about perspective in perspiration season -- we do have stretches of nasty heat and humidity, stretches where nights are very warm and stretches of 90 degree weather. It's a part of life around here. However, the magnitude of the 90 degree weather has been less significant compared to past years, even if the trade-off has been an increase in the magnitude of rainfall.