D.C.’s Chaotic Start to October

 

The White House, Washington, D.C.

Temperatures over the first week of October have ranged from November-like cold to warmth more typical of early June.  A significant amount of rain has fallen so far this month.  That’s in contrast to last October when a combined total of less than 0.5” of rain occurred during the first three weeks.

October 2021 was also a warm October in the Nation’s Capital with eight days highs reached the 80s.  That’s more than double the average of between three and four October days in the 80s in Washington, D.C. over the last 30 years.  Low temperatures were also quite warm last October with the coolest temperature in Washington, D.C. during the entire month of 47° on October 19.  That was the warmest “cool” temperature the month of October has featured in D.C. over the last 30 years.

NOAA’s Climate Prediction Center expects this October to be a cooler and wetter than average month in the Nation’s Capital.  This month got off to a wet start with measurable rainfall on the first five days totaling 1.75”.  That gave Washingtonians the wettest first week of October since 2006 (2.25”).  The wettest day so far this month was October 2 with 0.55”.  Although no rainfall records were set in the Nation’s Capital, having so many rainy days consecutively is unusual.  The rain was initially the result of the remnants of Hurricane Ian that gave way to a slow-moving coastal storm.

Temperatures were cooler than average on nine consecutive days in the Nation’s Capital through October 5.  The high temperature of 55° at both National and Dulles Airports on October 4 set records for coolest high temperature for the date.  Highs of 55° aren’t “average” in the Nation’s Capital until November 25.  By comparison, yesterday’s high temperature of 81° is more characteristic of early June.  Washingtonians have experienced at least one day of 80° warmth in 17 of the last 20 October’s through last year.  D.C.’s high of 81° yesterday ensured that streak will continue for at least one more year.

However, the June-like warmth was short-lived as a cold front passed through the D.C. Area last night.  Below average temperatures are expected for the next several days with no more 80° warmth on the horizon.  Temperatures tonight are expected to fall to levels not seen since the spring with low 40s downtown and mid-to-upper 30s in the suburbs.  The last time National Airport was colder than 45° was May 9 (43°), while the last time Dulles Airport was in the 30s was also on May 9 (37°).