Now that June is in the books and meteorological summer is one-third of the way through, how do the prospects for severe weather look in a typical July weather pattern in the District?
The severe weather season in the Washington area has been unrelenting! Four tornadoes touched down in Maryland on June 10 and then three days later two more were confirmed. Reagan National had 2.77 inches of rain also on June 10th, which surpassed the former 24-hour rainfall record of 2.27 inches. There were NO daily record high temperatures set at either airport (Dulles or Reagan National).
Now that we are transitioning into the second month of meteorological summer, how do our odds stack up for severe weather? July leads the year with the most occurrences of high winds from thunderstorms, with an average of 92 reports across the region. Hail is less frequent in July with an average of 19 reports, compared to May, which leads the year with an average of 25.
Not such a good statistic here…. July averages the most tornadoes in the region, with 6. May, June and September tie for second place with an average of 4 tornadoes for each month.
Breaking down the severe weather coverage by hour, the least likely time for severe weather is 5 a.m.; 6 p.m. is the prime time for severe storms. Looking at the chart below, hail is most likely to occur between 4 p.m. and 5 p.m., damaging winds between 5 p.m. and 6 p.m. (21-22 UTC) and tornadoes in the 4 p.m. and 6 p.m. hours.
A trend seen in the last 30 years is for more frequent severe weather to occur, with a spike from 2002-2003.
July is also the hottest month when the average high peaks at 89 degrees from July 7 to July 22. The hottest temperature ever recorded in the nation’s capital also occurred in July on the 20th when the mercury climbed to 106 degrees. This was during the Dust Bowl era…in 1930.
Keep these statistics in mind when planning outdoor activities far in advance when the weather is the least predictable. These figures can help you make alternate plans just in case.
Have a safe 4th of July holiday and well wishes for a great second month of summer! (All data is courtesy of the National Weather Service in Sterling, Va.)