D.C. faces the hottest weather so far this year on Friday, and just wait until next week

This spring has been warmer than normal in the DC area, but we have largely avoided the big heat. Since a record-breaking hot day in early May, highs had not reached 90 degrees.

That’s about to change, and potentially on a large scale.

We should be back to 90 degrees on Thursday. So we could top 95 degrees on Friday, the highest temperature so far this year.

But those two days may be just an appetizer. Next week looks brutally hot and the District could reach 100 degrees for the first time since 2016. It could also mark the beginning of an extended period of unseasonably hot weather similar to what we’ve experienced in some of our most brutal summers.

Once we hit mid-June, periods of pleasant weather last a limited time in the DC area, especially in this era of human-caused climate change. Enjoy the fairly mild weather we are experiencing earlier this week while it lasts.

The National Weather Service’s Climate Prediction Center is highlighting the potential for excessive heat along much of the Interstate 95 corridor from Richmond to Boston next week, beginning around Tuesday and continuing through at least June 24.

A combination of numerous computer model projections shows a pair of 90-degree days on Thursday and Friday of this week, and then a prolonged stretch of highs in the mid-90s starting next week. These projections could be conservative.

Some of the most reliable individual computer models predict highs near and above 100 degrees by the middle of next week, although they sometimes overestimate the magnitude of the heat.

With the burst of heat this Thursday and Friday, humidity will increase, but should not reach oppressive levels. But that might not be the case next week.

The weather pattern can generate not only heat but also very high levels of humidity. Heat indices (a measure of how hot it feels taking into account humidity) could approach or even exceed 105. That would trigger heat advisories or even excessive heat warnings for the area.

Why dangerous and unprecedented heat is possible

Models project that the heat dome that will be built over the Washington region will reach an intensity that has been associated with highs around 100 degrees in the past. In the second half of June, these maximums reach a record level.

Such extreme heat would pose risks to vulnerable groups such as outdoor workers, the homeless, older adults and anyone without adequate means to stay cool and hydrated. Nighttime low temperatures will also likely remain very warm, exacerbating risks for anyone without access to air conditioning.

Once next week’s heat wave begins, there is no obvious end to it in model forecasts.

Projections beyond next week show a continuation of warmer than normal weather across much of the lower 48 states.

The summer of 2016, the last to feature triple-digit highs in DC, began with relatively pleasant weather and only one 90-degree day as of this date, similar to this year. It ends up ranking as the third hottest on record. Like this year, it also followed an El NiƱo winter.

Highs reached at least 90 degrees on 58 days, including the highest number of days on record between July and August. It reached at least 100 in four days, once in late July and three times in mid-August.

Our own Capital Weather Gang summer outlook identified 2016 as a summer that may share characteristics with this one.

Jason Samenow contributed to this report.