Halloween: DC’s Scariest Weather of the Year?

 

October 2020 has been a memorable weather month in the Nation’s Capital.  Although it will finish warmer than average, today has been quite chilly with highs only around 50°.  That’s more characteristic of early December than late October.  Halloween will be cold this evening with temperatures in the 40s.

Through October 30, DC’s average monthly temperature (combining daily high and low temperatures) is 62.4° (2.8° above average), making this DC’s fifth consecutive warmer than average October.  The last time the Nation’s Capital experienced that kind of streak was 1982 – 1986.  Although no 90° heat occurred this October, there were two days with highs in the 80s.  In fact, DC’s high temperature of 80° on October 22 was the latest 80° temperature in the Nation’s Capital during October since 2014.  

The DC Metro Area also had a wetter than average month largely due to the remnants of two tropical systems.  The remnants of Hurricane Delta brought a two-day total of 1.54” of rain on October 11-12.  Meanwhile, the combination of ex-Hurricane Zeta and a cold front brought 2.57” of rain on October 29-30.  There has been a total of 4.86” of rain at National Airport since October 1, making October 2020 the second straight wetter than average October.  However, if you subtract the rain from the former tropical systems, this would have been a dry month with only 0.75” of rain compared to DC’s October average of 3.40”. 

Some may wonder what Halloween weather is like historically in the Nation’s Capital.  Last year couldn’t have been more different than this year, with a high/low of 77°/53°.  It was also a wet Halloween last year with 1.25” of rain.  DC’s average high/low temperatures on October 31 are 64°/46°.  That’s compared to DC’s record October 31 high of 85° from 1950.  Meanwhile, today’s record low is 26°, which last occurred in 1917. 

Over the last 25 years, DC has had measurable rainfall on only two Halloweens: 2002 and 2009.  The warmest Halloween in recent times was in 2004 when the high/low temperatures were 79°/59°, respectively, at National Airport.  Meanwhile, DC’s chilliest Halloween over the last 25 years occurred in 2002 with high/low temperatures of 47°/38°.  Today’s temperatures will be close to the cold Halloween Washingtonians experienced in 2002.  Fortunately, for those who don’t like the cooler than average weather, a warm-up will occur later next week.