Can One Month be Warm, Cold and Near Average ?

As January 2018 comes to a close, it’s a good time to discuss some of its weather extremes.  As of January 27, this month has had seven days with high temperatures in the 20s and another eight days with highs in the 60s.

Although January got off to a frigid start with colder than average temperatures on 10 of the first 15 days, DC temperatures have been warmer than average on eight of the last 12 days since January 15.  That’s left this month’s average temperature at 35.0° (only one degree below average).  Official weather measurements for Washington, D.C. are made at National Airport (DCA).

A major shift in the position of the jet stream has caused milder than average temperatures over the second half of January across the DC Metro.  Unfortunately for snow lovers, it has been a relatively dry month with no significant winter storms during the unusual cold wave earlier this month.  There has only been 1.2” of snow this month, well below DC’s January average of 5.6”.

The eight days this month with high temperatures at or below 32° was DC’s highest such total since 2005.  Amazingly, this month has also had eight days with high temperatures in the 60s for the highest such total since 2006.  January 2018 joins a rather elite club of only nine other months with eight or more 60°/+ days dating back to the 1870s.  Eight of those months rank in DC’s Top 10 warmest January’s according to the National Weather Service.  January 1950 had a record 14 days of 60° or warmer and remains DC’s warmest January on record.

Since January’s temperatures will ultimately finish close to average, it’s important to mention what has become January’s primary weather story in the Mid-Atlantic.  That is the moderate to severe drought conditions which now exist for almost the entire DC Metro Area.  As of January 27, Washington, D.C. has a rainfall deficit of nearly 9” since September 1, 2017.  Fortunately, the DC Metro Area had some much needed rainfall today.  NOAA expects roughly equal chances of above or below February precipitation for the DC Metro Area.