We declare it's summer in the D.C. area.

On the hottest day of the year so far, there’s no doubt summerlike weather is here to stay.

Every year, there comes a point — usually in May or early June — when days with highs in the 70s are mostly history and 80s or higher become the norm. We’re there.

As such, we declare the end of spring and start of summer in the D.C. area. We make this pronouncement as it’s 94 degrees outside — the hottest day of the year so far.

Spring arguably ended Saturday, when we kicked off Memorial Day weekend, considered by many the unofficial start of summer irrespective of the weather. That day it hit 80 degrees, and now there’s no turning back.

For the next 10 days, highs are forecast to reach the 80s or 90s. Chances of appreciable cooling after that are slim. By June 10, our average high is 84 degrees, and the National Oceanic and Atmospheric Administration is favoring a warmer-than-normal month for the area.

While some people subscribe to the meteorological (June 1) and astronomical (June 21) definitions for the start of summer, we consider it summer in Washington when the forecast calls for the majority of days to reach at least 80 degrees in the weeks to come.

https://www.washingtonpost.com/weather/2022/05/31/dc-spring-over-summer-2022/?