Great Falls, MD |
October is a fine month in the Nation’s Capital. Average temperatures range from a high/low of
74°/56° on October 1 to 64°/46° by Halloween.
Washingtonians can also expect an average of 3.4” of rain in
October. NOAA’s forecast for October is
for a warmer and drier than average month.
Such a forecast doesn’t differ much from recent
years. Four of the last five Octobers
have been warmer than average. The
warmest October on record in the Nation’s Capital occurred ten years ago in
2007. Washington, D.C.’s hottest October
temperature on record was on October 5, 1941 (96°). 90° temperatures in October are relatively
rare in the Nation’s Capital. No 90°
heat has occurred in October in the Nation’s Capital since October 6, 2013
(91°). The latest in the season
Washingtonians have had 90° heat is October 11 (90° in 1919).
By comparison, the coolest October temperature on
record in Washington, D.C. is 26° that occurred twice (on October 30, 1873 and
October 31, 1917). Official weather
observations for the Nation’s Capital have been made at National Airport since
it opened in 1941. Prior to that, they
were made downtown. Washington, D.C.’s
coolest October temperature at National Airport occurred on October 24, 1969
(29°). The earliest in the season
measureable snowfall has occurred in the Nation’s Capital was on October 10,
1979 (0.3”).
Some current or former tropical systems have impacted the
Mid-Atlantic Region in October. Memorable
ones in recent decades include the remnants of Hurricane Opal in 1995 and the
remnants of Hurricane Sandy in 2012. By
the time Sandy made landfall, it was considered a “post-tropical” storm since
it had lost its tropical characteristics over cooler waters. However, the gusty winds and heavy rainfall that
occurred with the remnants of Sandy were virtually identical to that of a
tropical storm.
The DC Metro Area could actually use some
rainfall. No measureable rainfall has
occurred in the Nation’s Capital since September 13 (0.04”). Washington, D.C.’s current streak of 18
consecutive days without measureable precipitation is significant, but not
record-setting. DC’s longest streak of
dry weather is 34 days (ending October 18, 2007) according to the National
Weather Service. The current streak
would have to reach 27 days just to crack the Top 5.
Although NOAA expects a drier than average month,
there is some precedent for a wetter than average October to follow a drier
than average September. September 2005
was DC’s driest on record (0.11”) and that was followed by the wettest October
on record (9.41”), largely because of the 7.3” of rain on October 5-6. For perspective, the record 7.3” of rain that
occurred during that two-day period is more than rain than occurred during all
of August and September 2017 combined (6.01”).
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