D.C.'s spring has ended, and summer is here to stay.
On the District’s first 90-degree day, we declare spring over.
As often happens in the D.C. region in late May, we flip the switch from spring to summer. This year, it’s happened in rather sudden fashion. After nearly two straight weeks of below average temperatures with highs in the 60s and 70s, we leaped into the 80s on Wednesday and, as if to clinch the birth of summer, soared to 90 degrees for the first time Thursday.
Looking at the forecast for the next one to two weeks, predicted highs are mostly in the 80s and 90s, with no sign of any sustained, cooler springlike weather.
Our definition for the start of summer in the District is the point at which the forecast calls for the majority of days to reach at least 80 degrees in the weeks to come.
This year’s onset of summery weather follows what was a rather pleasant, though short spring. We declared winter over on March 22, meaning our spring season lasted roughly eight weeks. . .
As we look ahead, there’s plenty of warmth in the pipeline and, soon enough, pools will open and vacationers will be flocking to the beaches.
Highs are predicted to be near 90 through the weekend before a brief pause in the heat Monday and Tuesday. Our declaration of summer’s arrival doesn’t mean we can’t or won’t have a cooler day or two in the weeks ahead. For example, Monday’s highs may only reach the 70s and long-range model projections indicate highs in the 70s again around May 28 or 29 in the wake of a cold front.'
https://www.washingtonpost.com/weather/2021/05/20/dc-spring-over-summer-arrival/?