Temperatures are going to reach into the 90s in parts of New England on Monday, and when you add in the humidity, it may feel close to 100 degrees for a few hours during the afternoon and early evening.
The best chance for this kind of heat is across the interior and southern portions of New Hampshire and Western Maine, possibly stretching down into Boston. Officials have issued a heat advisory in those areas, something put into effect if the temperature is expected to feel above 100 degress for more than 2 hours in a day.
Notice the advisory doesn’t extend to the south shore or Cape Cod. This is because the southerly component of the air coming off Long Island Sound is going to tend to keep temperatures from reaching extreme levels. If the wind is strong enough, it could even keep Boston from breaking the record.
The breeze Monday will help take the bite out of the heat. Since this in the first really hot day of the summer, it’s a good idea to hydrate and take it easy from 1 p.m to 5 p.m., which is when the heat is expected to be most intense.
If Boston exceeds 94 degrees, we will have a new heat record for June 18. Interestingly, that record — which was set back in 1929 — is the lowest high temperature record for the month of June. This means that if we do reach a new record — unless we get towards 98 or 99, which is not likely — the new record would just be in keeping with all the other ones for the month. Meanwhile, it’s possible that the record of 93 in Worcester — also set in 1929 — could be broken, but I think we’ll probably end up getting close rather than going above it.
Even if Boston doesn’t break the record Monday, it’s certainly going to be the hottest day so far this season. Summer officially begins Thursday just after 6 a.m., and we can look for more of these warm days ahead.
Is this a new heat wave?
This is not the start of a new heat wave, which the National Weather Service defines as at least three consecutive days with highs of at least 90 degrees. The rest of the week looks warm and more typical of July rather than June, but I’m not expecting any more record-breaking heat.
Even more notable, the humidity — which will increase during Monday afternoon and peak in the evening hours — will actually fall back during early Tuesday. I don’t expect the humidity to be a factor for several days after Monday.
What about thunderstorms?
There is the chance for some thunderstorms as a cold front crosses the area Monday evening and overnight. There’s going to be a tremendous amount of moisture in the air, so if you were to get a shower, you can expect some very heavy downpours. We desperately need rain and it would be great to see it, but the energy in the atmosphere is not so dramatic that the showers will be really widespread. If we miss the rain Monday night, there’s not really another chance for at least about a week.