What Has Been April's Dominant Weather Story?

Now that we’re roughly midway through the month of April, it’s a good time to see how the weather compares to average so far given how diverse the weather has been in the Nation’s Capital.  Through April 13, temperatures have been more than two degrees below average at National Airport. April has also been cooler than average at Dulles Airport in nearby Sterling, Virginia, and in Baltimore, Maryland.

That’s consistent with NOAA’s forecast for cooler than average temperatures across the Mid-Atlantic Region for the first half of the month.  Although the high temperature reached a June-like 83 degrees on April 1 in the Nation’s Capital, this month has also had snowfall on three different occasions.  Low temperatures have also fallen to the 30s six times during the last two weeks. That includes three days where downtown temperatures reached or fell below the freezing mark.

By comparison, temperatures only fell below 40 degrees once last April - when it was 39 degrees on April 24. April 2015 had twelve days with high temperatures in each the 60s and 70s compared to only five such days so far this month.  Although the first 80-degree day of 2016 occurred earlier than in 2015 (April 1 vs. April 13), the weather pattern so far this month has been different. Unlike last April or last month (one of the warmest Marchs on record in the DC Metro Region), the weather pattern has been different during the first half of April with cooler than average temperatures.

The good news about the generally cooler than average temperatures so far this month, has been an overall reduction in the amount of thunderstorms and severe weather in the Mid-Atlantic and northeastern United States. Although a few severe wind gusts occurred in thunderstorms on April 7, there haven’t been any large severe weather outbreaks so far this month in this part of the country.  NOAA data shows some severe weather occurred in the DC Metro Region on April 20 and 22 of last year, but there haven’t been any April tornadoes in this part of the country since 2013.

However, there is going to be a major shift in the weather pattern for the second half of April. Although temperatures will be slightly cooler than average today and tomorrow, Washingtonians will see a gradual warming trend during the next several days. Dry weather is expected to continue into next week as temperatures warm to near 70 degrees on Sunday and could approach 80 degrees in spots on Monday.  The warmer than average conditions NOAA expects during late April should help this month finish with closer to average temperatures.  The Nation’s Capital hasn’t had a cooler than average April since 2007.