The last time Washington, D.C. experienced low temperature below 15 degrees was March 3, 2009 (low of 14). (Interestingly, it was not as cold as this during Snowmageddon). Tonight, the mercury may plunge to levels a degree or two colder than that. Wind chills may flirt with zero, or a few degrees below. The thermal recovery Wednesday is modest, with afternoon temperatures stuck in the 20s.
Through Tonight: Temperatures in the 20s fall into the teens by 9 or 10 p.m. in most spots. By early in the morning, lows range from the high single digits to mid-teens. I’ll call for a range of 8-15 (suburbs-city). Factoring in winds from the northwest at 10-14 mph, it will feel as cold as 3 degrees to 3 degrees below zero. Skies are mostly clear. Be sure to bring pets inside and you might consider turning off water to outdoor pipes. A humidifier is also advisable due to the very dry air.
Wednesday: The day begins mostly sunny with a deceptive chill. As the day wears on, high clouds increase ahead of an upper level disturbance approaching the region (which could produce some flurries or snow showers overnight). Highs range from 22-26 (suburbs-city). It’s breezy, with winds from the west at around 15 mph, with some gusts 20-25 mph at times. Wind chills will be in the single digits and teens.