Feeling More Like Fall

Although October got off to a sizzling start in the Nation’s Capital with four hot days, this weekend has felt much more like autumn.  Nevertheless, Washingtonians have had an exceptional start to October with a temperature spread of nearly 50° in the span of three days.

The high temperature in Washington, D.C. reached a July-like 98° on October 2.  That not only obliterated the previous daily record high of 89°, but it also set a new record for DC’s hottest overall October temperature.  It was also DC’s 62^nd day of 90° heat of 2019.  That puts this year solidly in second place for highest annual total of 90° days behind only the total of 67 days that occurred in 2010 and 1980.  The Nation’s Capital averages only 36 days of 90°/+ in a given year.  By comparison, DC had an above average but much lower total of 45 days of 90° heat last year.

Yesterday’s high temperature of 67° at National Airport was DC’s coolest high temperature since May 14 (64°).  The low temperature of 49° yesterday was also the coolest temperature in the Nation’s Capital since April 29 (47°).  Those temperatures are common in the DC Metro Area in the fall, but not for a few more weeks.  For example, DC’s average high/low temperature on October 19 is 67°/49°.

Although Washingtonians often see the final day of 90° heat of the year in September (13 of the last 26 years), October has now had 90° heat six times since 1993.  The first frost of the fall season doesn’t typically occur within Washington, D.C. city limits until the second week of November.  However, the northern and western suburbs often see frost in mid-to-late October.  Fall allergy sufferers actually look forward to the first frost of the fall since it eliminates many environmental allergens such as ragweed and grass pollen.

Measurable snowfall has also occurred in the Nation’s Capital on more than one occasion during the month of October.  DC’s earliest accumulating snowfall of the season occurred on October 10, 1979 (0.3”).  However, having a significant amount of snowfall before December 31 doesn’t always correlate to a cold and snowy winter.  A good example of this occurred during the 1989-1990 winter season.  Washingtonians had a combined 12.5” of snow in November and December but less than 3” occurred the rest of the winter.

Temperatures will be milder today compared to yesterday with high temperatures in the 70s.  NOAA’s Climate Prediction Center expects near average temperatures to continue in the DC Metro Area through the middle of the month.  DC has a rainfall deficit of nearly 5” since August 1 and that’s contributed to moderate drought conditions for a significant portion of the DC Metro Area.  While some showers are possible tomorrow evening, no significant rainfall is expected.