Early Saturday, May 9, Boston started out on a relatively calm note with partly cloudy skies and about 45°F at Logan Airport, but the day is on track to turn soggy fast. Rain showers are expected to develop through the morning and become widespread by mid‑afternoon into the evening, with a high near 57°F. Some pockets could see brief heavy downpours or an isolated thunderstorm. Most spots can expect roughly a quarter to a half inch of rain, with localized higher totals in any heavier cells.
Timing, Winds And Travel Impacts
Between about 7 a.m. and 5 p.m. on Saturday, May 9, look for the steadiest showers and the best chance for embedded thunder, which could slow the afternoon commute. South winds will generally run 2–13 mph, with coastal gusts up to around 25–30 mph, and the heavier rain will cut visibility on local roads and transit routes. Aviation conditions may slip from low‑end VFR to MVFR or IFR in the most intense bands, so travelers should be ready for a higher chance of delays at Logan this afternoon and evening.
Forecast Update And Sunday
Forecasters have shifted the main axis of heavier rain farther south for the Sunday night into Monday stretch, trimming the odds of a widespread soaking across greater Boston, according to the National Weather Service Boston/Norton. The office also has a Small Craft Advisory posted for many coastal waters from around noon Saturday into early Sunday, so mariners will want to plan around rougher conditions. That is a change from our earlier outlook. See our foggy May 7 outlook for the prior guidance. Sunday, May 10 should run milder with patchy morning fog and a high near 66°F, while Monday, May 11 turns cooler with scattered showers.
Quick Tips
Bring a waterproof layer if you have outdoor plans on Saturday and build in extra time for errands and school runs during the afternoon and evening rain. If you have critical travel, it is worth considering a shift to Sunday afternoon when conditions look drier, and small‑boat operators and ferry riders should check carrier notices before leaving the docks. We will update this page if advisories or timing change for Sunday night into Monday.
