It is muggy and mild at Reagan National Airport early Monday, May 18, 2026, sitting around 68°F, and it only goes up from here. Forecasters are calling for a near-record burst of heat, with highs near 95°F on Monday and another trip into the mid 90s on Tuesday, May 19, 2026. Skies will be mostly sunny, and the humidity will add extra punch, making the afternoons feel hotter than the calendar would suggest for May.
Afternoon Peak And Midweek Shift
Strong May sun and steady south winds are expected to drive temperatures into the mid 90s by midafternoon, roughly 3 to 4 p.m., on Monday, with Tuesday likely running a bit hotter. Overnight, the air does not cool much, with lows only dropping into the upper 60s to low 70s, so there will be limited relief for open-window sleepers.
A strong cold front is projected to move through on Wednesday, May 20, bringing widespread showers and thunderstorms during the afternoon and evening, followed by a sharp cooldown. That turn in the pattern, from mid 90s to stormy and then cooler, comes courtesy of the National Weather Service.
Boaters And Outdoor Plans
For boaters, this hot stretch comes with choppy side effects. A Small Craft Advisory is expected for parts of the bay and the lower Potomac from about 3 p.m. Monday through 2 a.m. Tuesday, thanks to southerly winds and gusts near 20 knots. Thunderstorms on Wednesday could bring even stronger gusts and rougher water, so this is not the ideal stretch to squeeze in a casual evening cruise.
On land, if you can shift your schedule, try to run errands or get outdoor chores done in the morning and avoid the midafternoon peak, when heat and humidity team up to make things most uncomfortable.
Find A Place To Cool Off
Residents without air conditioning do not have to tough it out alone. The District operates cooling centers and posts heat-safety information, with locations and details listed at Keep Cool DC. You can also call 311 for help getting to a cooling center.
Standard summer rules apply, even if the calendar still says May: drink plenty of water, limit strenuous outdoor activity during the hottest part of the afternoon, and check on older neighbors or anyone with underlying health conditions who may struggle in the heat.
What To Watch
The main windows to keep an eye on are the midafternoon hours Monday and Tuesday, when temperatures are expected to peak in the mid 90s, and Wednesday afternoon into evening, when the cold front arrives and showers and thunderstorms become most likely.
Keep tabs on updates from local forecasts or AlertDC for any thunderstorm or marine warnings that could affect evening commutes, outdoor events, or time on the water.
