Humidity is also on the rise but should end up a hair lower than the oppressive levels we sweated through during July and August. Dew points, a direct indicator of humidity, should max out near 70 rather than 75 to 80. In other words, it will feel muggy out but not quite gross.
The slightly lower dew points also mean nighttime temperatures will fall back a bit more, generally ranging from the upper 60s in our cooler areas to the mid-70s downtown. This will make the early morning hours in particular a bit more tolerable.
But with the blazing sun beating down on us during the day, it will be very toasty — something that coaches in charge of afternoon sports should take into consideration.
Thursday, Friday and Saturday will likely be the hottest and most humid days. Highs should range from the low-to-mid 90s across the region, with a few upper 90s possible — especially near and in the city.
Heat-index values, which indicate what it feels like factoring in the humidity, should top out around 100.
Record highs are mostly out of reach on Wednesday and Thursday, except at Dulles (which has a relatively short period of record). But Friday and Saturday, some records could be challenged, especially if the hotter models, which forecast highs in the upper 90s, are correct.
Somewhat cooler and much less humid air is forecast to move into the region Sunday behind a cold front.
Washington is likely to add five more days at or above 90 degrees to 2016’s count, bringing the total to 56, which would tie for the eighth most on record during a calendar year (if there are more 90-degree days after Saturday, the 2016 ranking would go up).
Capital Weather Gang’s Matt Rogers, who specializes in long-range forecasting, says this week’s heat wave isn’t this year’s last chance for 90-degree weather. “There will be more opportunities,” he said. “But there shouldn’t be as many hot days in a row, and the heat shouldn’t be as intense.”