How Will This October Be Remembered?

Autumn is a Beautiful Time of the Year

October is a transitional fall month that can be remembered for major events such as record warmth as in 2007 or Sandy in 2012.  More often than not, though, October is a fairly quiet weather month in the Mid-Atlantic Region.  This October has continued the 2016 trend of being drier than average.

The Nation’s Capital has an on-going rainfall deficit of 7.94” dating back to August 1, 2015.  Since January 1, the deficit is 4.96” since eight of the ten months of 2016 have featured below average rainfall.  There has been only 0.90” of rain at National Airport this month setting this October up to be the driest in Washington, D.C. since 2001 (0.69”).

There is a similar rainfall deficit at Dulles Airport which has a 7.68” rainfall deficit dating back to August 2015.  Only 0.6” of rain has occurred at Dulles Airport this month that would make this October their driest since 2000 (when only 0.06” of rain fell).  Temperatures this month have been significantly warmer than average in Washington, D.C. with an average monthly temperature (combining daily high and low temperatures) 3.4 degrees above average (through October 29).  The record warmth that occurred in the Mid-Atlantic Region when there were four consecutive days in the 80s (October 17 – 20) is a key contributor.  

The combination of warmer than average temperatures and below average rainfall the last several months have lead many fall weather enthusiasts to wonder what influence that will have on the fall foliage.  The above average temperatures in September and October have caused a slight delay of peak fall colors.  In the DC Metro Region, the leaves don’t typically reach their peak fall colors until late October and early November.  However, the dry weather typically causes leaves to fall more quickly than they otherwise would.  Whether or not any gusty winds occur can also influence how long the leaves remain on the trees.

It’s appropriate given how warm this month has been that record warmth is possible this afternoon as temperatures approach 80 degrees in the Nation’s Capital.  Today’s record high at National Airport is 82 degrees and 81 degrees at Dulles Airport (both from 1996) compared to the average high of 64 degrees for October 30.  However, temperatures will be more seasonal for Halloween tomorrow.  

According to the National Weather Service, the last time measureable rainfall occurred on Halloween in Washington, D.C. was in 2009.  The warmest Halloween Washingtonians have had in the last twenty years was in 2004 when it was 79 degrees while 2002 featured the coolest Halloween at 47 degrees.  Tomorrow’s temperatures in the Nation’s Capital will be more like last Halloween when it was 61 degrees.