Forecast: Today Will Mark First Heat Wave Of Summer

Sunday marked the fourth day this month Logan Airport has reached 90 degrees, with two of those days coming earlier in the month before a cooling period.

Both days this weekend reached 90 degrees, and today will mark the fifth 90-degree day this August and the 3rd in a row. Since we will reach 90 degrees again today, this will be our first official heat wave of the summer, and the first since a prolonged heat wave between July 14 and July 20, 2013.

High pressure off the southeast coast of the United States is going to act like a heat pump much of this week and bring humid and hot air north. There will be a break in the core of the heat on Thursday, but not before we have a five-day heat wave.

The overall pattern has shifted enough so as to show a flow of muggy air present in the forecast for the next week or longer. This prolonged period of humidity is going to make it quite difficult to sleep for the foreseeable future, although we may get used to it as the week goes along.

If you are on vacation this week, it does look wonderful for all outdoor beach activities. However, if you plan to do more strenuous activities, I would try to get them done in the morning before the heat is at it’s worse.

I don’t see any widespread rain or thunderstorms in the forecast, but there could be some shower activity in isolated pockets on Tuesday and again late in the week or early next weekend. The 90s will break by Thursday, but remember, it’s not going to cool off anytime soon. It will just be less hot.

Today: Sunny, with a high in the low to mid 90s.

Tonight: Warm and humid. Lows 65-70.

Tuesday: Mostly sunny and humid. Hot in the afternoon. Highs around 90.

Wednesday: Mostly sunny, with a high 85-90.

Thursday: Partly sunny, with a high near 85.

Friday: Muggy and warm A few showers. Highs in the low to mid 80s.

You can follow David’s weather updates on Twitter at @growingwisdom.