Typical October Weather in DC ?

NOAA Expects Above Average October Temperatures Over the Eastern U.S.

September 2018 was a unique weather month in the Nation’s Capital. A total of 9.73” of rain was officially measured at National Airport, making last month the fifth wettest on record in Washington, D.C.  It also featured a record 16 days of measurable rainfall.

Also, September 2018 finished tied with September 2010 for DC’s fifth warmest on record with a monthly average temperature (combining daily high and low temperatures) of 75.5°.  That’s the first time DC has had a September that ranked in the Top Five wettest and warmest months since official weather records began in 1871.  Despite measurable rainfall on eight of the final 10 days of September, temperatures were above average on seven of those 10 days.

October 2018 has gotten off to a much drier start.  Warmer than average temperatures are expected to continue for the first half of the month.  In fact, NOAA’s outlook for the entire month of October is for warmer than average temperatures with near average precipitation.  Near average precipitation should sound good to the majority of Washingtonians, following the especially rainy weather over the final third of September.

DC’s average high/low temperatures drop significantly over the course of the month from 74°/56° on the October 1 to 64°/46° on October 31.  DC’s hottest October temperature on record was 96° on October 5, 1941.  Meanwhile, DC’s coldest observed October temperature of 26° has occurred three times, most recently on October 31, 1917.  Eleven of the last 20 October’s, have been warmer than average in Washington, D.C., including five of the last six.

Although rare, the Nation’s Capital can experience 90° heat in early October.  The last time 90°/+ heat was observed in Washington, D.C. was on October 6, 2013 (91°).  Temperatures at or below freezing in October are also relatively rare in the Nation’s Capital, with the majority of such temperatures occurring before National Airport opened in the early 1940s.  Prior to National Airport opening, weather records for the Nation’s Capital were kept downtown.  Overall, the last time temperatures at or below freezing occurred in the Nation’s Capital during the month of October was on October 20, 1992 (32°).

Washington, D.C. averages 3.4” of rain in October and half of the last 20 October’s have been wetter than average.  The DC Metro Area occasionally experiences heavy rain from former tropical systems such as the remnants of Hurricane Opal that produced 1.99” of rain on October 5, 1995 and ex-Hurricane Sandy that produced 4.69” of rain on October 29-30, 2012.  The earliest in the season the Nation’s Capital has had measurable snowfall was October 10, 1979 (0.3”).

NOAA's Precipitation Outlook for October