This morning, Sunday, May 17, 2026, Boston woke to clear skies and about 61°F at Logan Airport, with humidity near 77%. The sun will stick around and temperatures should climb into the upper 70s to around 80°F inland by mid to late afternoon. That bright, warm air is a quick preview of a hotter stretch expected later this week.
Afternoon Winds Pick Up
Expect a sunny afternoon with a high near 80°F and west winds of 8 to 15 mph, with gusts up to 26 mph that will make bike rides and light outdoor tasks feel breezier. Small-Craft Advisories and seas near 5 feet are in effect for some southern waters into the afternoon, so boaters should secure loose gear and avoid nonessential trips. According to NWS Boston, winds should diminish tonight as the flow shifts north.
Heat Spike Tuesday and Wednesday
Tuesday, May 19, 2026, and Wednesday, May 20, 2026, look markedly hotter, and forecasters warn near-record heat is possible, with inland highs potentially reaching the low 90s away from the immediate coast. Humidity will be on the rise, making afternoons feel hotter than the thermometer alone. This first real heat event of the season may hit people who are not yet acclimated harder than a typical summer day. If you need relief, the City of Boston keeps a cooling-center guide and list of BCYF locations and resources at City of Boston.
Thunderstorm Risk Midweek
A cold front is expected to move through Wednesday afternoon, May 20, 2026, and trigger scattered showers and thunderstorms after about 2 p.m. Some storms could produce strong wind gusts and heavy downpours. The primary hazards appear to be damaging wind and brief heavy rain that could lead to localized ponding, so outdoor events should have a quick indoor backup plan. Keep an eye on forecast updates Wednesday if you have afternoon or evening plans.
Tonight and Commute Notes
Tonight will be partly cloudy with a low near 54°F, and north winds easing to light levels, setting up a cooler Monday, May 18, 2026, morning near the coast. Inland areas will warm back up Monday before the bigger jump on Tuesday, so plan errands and outdoor work accordingly. For mariners and commuters, expect generally VFR conditions through Monday and a return to breezy conditions by midweek.
