The heat rolls on! Yesterday was hot, but today is the real deal. Yesterday felt more like a hot summer day you get a few times every year. Today was another level, reaching 100° in Boston! Highs yesterday were in the low to middle 90s for many of us, compared to the mid and upper 90s (even 100°) today. For an official heat wave you need three consecutive days reaching 90°. Most towns will achieve that tomorrow, but if you missed Wednesday, you’ll have another shot at 90° on Saturday.
It’s probably not a surprise, but hitting 100° this afternoon gives us the hottest day of the year so far in Boston. We’ll have another shot tomorrow.
The extreme heat warning we have in effect (heat advisory for the Cape) will continue all the way through Saturday. It’s not until Sunday that we see true relief from the extreme heat, and even then it’s all relative because Sunday is still a warm day.
The extreme heat warnings and heat advisories are issued for a multitude of reasons. Of course the most obvious is it’s hot and feels even hotter. That’s clearly the case today and again tomorrow but it also factors in the duration of the heat and humidity and how much relief we see during the overnight hours. In the case of this stretch of heat, it is here for four days: Wednesday, Thursday, Friday and Saturday. Each day is hot and humid, but especially Thursday and Friday. And we aren’t seeing a lot of overnight relief to let your body recover if you don’t have A/C. Temperatures tonight will only fall to the upper 70s. For perspective, our average high temperature is 81°.
Tomorrow will give us another chance at 100° across the area. Whether it actually reaches 100° or not, it will feel like it! Heat index values will climb to 105° or more tomorrow afternoon.
Boston has hit 100° now 29 times since records began back in 1872. That averages out to about once every 5 years. So hitting 100° in a given summer, while not rare, is not a guarantee. Hitting it twice would be even more impressive if we can do it again tomorrow. And doing it twice in back-to-back days would be a rare feat. That last time Boston hit 100° in two consecutive days was back in 1944! It would only be the fourth time in recorded history that that’s happened.
So how long does the heat last? Well there’s an end in sight. That end will come during the day on Saturday. Before the front, it’s still hot and humid with highs climbing to the 90s. Scattered showers and storms will move through Saturday afternoon and evening and break down this heat and humidity. Now what’s on the back side is all relative — it’s still a warm day with numbers reaching the 80s Sunday afternoon, but the humidity will be less too. While it may still be warm, it definitely will feel like quite the relief after what we dealt with today and will with again tomorrow.
There’s a bigger cool down on the way for early next week with an increasing likelihood of a good soaking rain Monday into Tuesday.
