Wednesday, April 12, 2017

April Temperature Extremes


NOAA's Temperature Outlook for Later in April

Yesterday marked Washington, D.C.’s third day of 80 degree warmth so far this month.  Such warmth is more characteristic of June than the first half of April.  Most Washingtonians are eager for the warmer weather of late spring, especially considering how chilly April can be.  Average high and low temperatures in Washington, D.C. range from 62/42 on April 1 to 71/52 on April 30.

Dating back to 1993, Washington, D.C. has averaged three or four April days with temperatures in the 80s.  So having three so far this month puts us right at that mark.  Temperatures in the Nation’s Capital have reached the 80s at least once in every April since 1999.  Ironically, the last April Washington, D.C. didn’t experience 80-degree warmth was in 1998, while March that year ended with a streak of 80-degree warmth on 4 out of 5 days.

Much less frequent than April 80-degree warmth in the Nation’s Capital are 90-degree temperatures.  Since 1993, there have been only 10 days at or above 90 degrees.  There hasn’t been any 90-degree heat in Washington, D.C. in the month of April since 2013.  The earliest in the year that the thermometer has reached 90-degrees in Washington, D.C. was March 22, 1907.  

Some longtime DC residents may recall the April heat wave that occurred in 2002.  A “heat wave” is defined as a minimum of three consecutive days at or above 90 degrees.  That’s exactly what Washingtonians experienced from April 16-18.  April 17, 2002 is the most recent of four times Washington, D.C. has experienced its hottest April temperature of 95 degrees.

Some may also wonder how common temperatures at or below freezing are during the month of April in Washington, D.C.  According to records kept by NOAA, temperatures at National Airport have been at or below freezing 14 times in April dating back to 1993.  That includes three times in April 2016.  However, temperatures have been below 30 degrees only twice in the Nation’s Capital during the month of April in the last 24 years.  Temperatures at or below freezing in April are only slightly more common than 90-degree heat is in Washington, D.C.  National Weather Service data indicates the last time measurable snowfall occurred in Washington, D.C. in April was on April 7, 2007 (0.4”).

NOAA’s current temperature outlook is for above average temperatures to continue over the next one to two weeks across much of the central and eastern United States. 

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