Spring-like Warmth in January !

While today’s high temperatures will be significantly warmer than average in the mid-50s across the DC Metro Area, highs will climb into the 60s tomorrow.  In fact, some portions of the DC Metro Area could reach 70° on Sunday!  Bear in mind that average high temperatures in the Nation’s Capital are only 43° through January 22.

As warm as temperatures will be this weekend, no record highs will be set downtown.  That’s because DC’s record highs on January 10 and 11 are in the mid-70s.  It’s difficult for the Nation’s Capital to reach 70° in January since official weather measurements are made at National Airport.  With its location on the Potomac River, winds blowing out of the south off the water tend to keep temperatures cooler than surrounding areas.  Washingtonians haven’t experienced 70° warmth in January since January 12, 2017, when the high reached 72°.

Dating back to the early 1990s, Washington, D.C. has averaged three days of 60° temperatures and roughly one 70° day every other year.  DC’s warmest January day was on January 26, 1950, when it was 79°.  Even 60° temperatures are relatively rare for DC residents in January as 60° isn’t DC’s average high temperature until late-March.  Similarly, Washingtonians can’t expect to see 70° warmth until late-April. 

However, there have been stretches of warm January weather in the Nation’s Capital in recent decades.  For example, DC residents enjoyed eight consecutive days of highs in the 60s from January 2 – 9, 1998.  January warmth of 70° has occurred on consecutive days only once (on January 4-5, 1997, with highs of 73° and 71°, respectively).

By comparison, DC residents had a frigid start to 2018 with highs in the 20s on six of the first seven days of January.  DC’s warmest January temperature since 2000 occurred on January 30, 2002 (77°).  Such rare January warmth can sometimes coincide with severe weather.  For example, DC had a high temperature of 72° on January 30, 2013 that was followed by several reports of severe wind gusts (60/+ mph) with the passage of a cold front.  

Following a warmer than average December in the Nation’s Capital, above average temperatures are poised to continue for much of the coming week.  That’s not encouraging news for winter weather enthusiasts.  There is precedent, however, for a shift from warmer and wetter than average (as the last six weeks have been) in the Nation’s Capital to colder and snowier than average weather.  December 2015 was DC’s warmest on record and no measurable snowfall occurred either during the first half of January 2016.  That was followed by DC’s fourth largest snowfall on record with 17.8” on January 22-23, 2016.