Memorial Day weekend is typically the unofficial start to summer, but it feels like we’ve already kicked it off with our first heatwave of the season. Boston typically sees 13 90°+ days per year. We’ve already seen 3 days at or above 90° and the city can see 90s all the way into October (that’s more than 5 more months of potential heat). I DON’T think we will be adding to that tally over the next 10 days. We’re entering back into a damp, cool and unsettled pattern for a little while. This time around we won’t we talking 30s and 40s, instead we’ll be experiencing 50s and 60s. Temperatures appear to stay below normal for the next 10 days. The average high temperature in Boston right now is 67°. Monday, we’ll stay in the 50s, Tuesday we briefly warm up to 70°, but low to mid 60s return by Wednesday. It will be interesting to see if we finish off the month of May with below average temperatures after our 4th May heatwave on record.
Let’s focus on the unsettled part of the forecast. The bad news – we are expecting numerous showers over the next 10 days. These showers will be very difficult to time out. The timing has changed significantly over the last 24 hours.
Round one of rain will arrive Monday afternoon (Monday morning in western New England). There will likely be a couple hour window of steady rain during the afternoon and evening, which will be enough to slow down the evening commute. Heavy rain could move in overnight and into Tuesday morning for extreme southeast Massachusetts. Right now, I think most of that rain should miss us to the south, but stay tuned.
Tuesday dries out and the sunshine will return. We’ll see typical May weather from the late morning on. Temperatures will reach the low 70s, but that will be the only mild day of the week.
Showers return Wednesday into Friday. Forecast models are doing poorly on the exact timing AND the amounts --- some show up to an 1” of rain others show inches of rain. Most of the models do dry us out for some of the holiday weekend. Currently, it appears the nicest stretch will be from Saturday into Sunday. Memorial Day, showers may return.