Monday July 21 2025 Forecast (7:30AM)

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DAYS 1-5 (JULY 21-25)

We know that low pressure areas can bring us a variety of weather. However, high pressure areas can do the same, in their own way, and the next 5 days will provide an example of that. It may not sound like it when I first say that high pressure will bring us fair weather today into Friday, until a cold front approaches and brings a shot at showers and thunderstorms later Friday. Fair weather is fair weather, but the differences are in wind direction / speed, air temperature, and dew point, based on the position of the high pressure area, and this is a big factor in how it feels. So how does that change during these days? Today, with the high center in the northern Great Lakes, the flow between it and eastern Canadian low pressure will deliver a cool, dry, Canadian air mass on a gusty northwesterly breeze. One note though: Usually on days like this week think of a cobalt blue sky to go with the pleasant air mass, but you’ll notice a bit of a hazy look instead, and this is due to a plume of wildfire smoke aloft from Canada. Tuesday, as the high center builds from the Great Lakes into New England, we’ll see the northwesterly breeze fade away, and much lighter wind which will then allow a coastal sea breeze to develops. Wednesday, the high center starts to move offshore to our east and southeast, so a cool and calm Tuesday night after the sea breeze collapses will be replaced with a light southerly air flow and the first up-tick in the humidity after two very dry days. The air temperature will also rise a little, with some areas breaking 80 after two days in the 70s. This day, the “coolest” air would be at the South Coast due to the southerly wind flow being directly off the ocean water, which does run slightly cooler than what the land will warm up to during the day. Thursday and Friday, high pressure will remain offshore to the southeast and pump in increasing amounts of heat and humidity, peaking on Friday ahead of the aforementioned cold front. So there is how the weather changes from one “fair weather” system during the course of several days. Still, it’s a pretty decent vacation week in the region if it’s the one you picked and you’re hanging around here, or visiting here from elsewhere. Enjoy!

TODAY: Thin smoke aloft, otherwise sunshine with some passing clouds. Highs 72-79. Dew point falls through the 50s. Wind NW 5-15 MPH, gusty.

TONIGHT: Mostly clear. Lows 51-58. Dew point below 50. Wind NW diminishing to under 10 MPH.

TUESDAY: Sunny. Highs 71-78, coolest in coastal areas. Dew point below 50. Wind variable up to 10 MPH with coastal sea breezes.

TUESDAY NIGHT: Clear. Patchy ground fog inland low elevations. Lows 48-55. Dew point below 50. Wind calm.

WEDNESDAY: Sunny. Highs 78-85, coolest Cape Cod / South Coast. Dew point rising through 50s to around 60. Wind S up to 10 MPH.

WEDNESDAY NIGHT: Mostly clear. Patchy fog interior low elevations. Lows 61-68. Dew point near 60. Wind S to SW under 10 MPH.

THURSDAY: Mostly sunny. Highs 78-85 South Coast, 85-92 elsewhere. Dew point in 60s. Wind SW 5-15 MPH.

THURSDAY NIGHT: Mostly clear. Lows 68-75. Dew point rises toward 70. Wind SW up to 10 MPH.

FRIDAY: Sunshine through midday. Clouds develop / arrive later in the day with a chance of showers and thunderstorms. Highs 88-95 except cooler South Coast / Cape Cod. Dew point 70+. Wind SW 10-20 MPH.

DAYS 6-10 (JULY 26-30)

There’s some uncertainty on the weekend forecast (July 26-27) based on the movement / positioning of the front that comes into our region later Friday. How I think it plays out is the front is still near the South Coast into Saturday with a shower and thunderstorm threat lingering in southern areas with fair weather to the north, and then the front lifts slowly back to the north with the help of an approaching disturbance from the west Sunday with eventually a better chance of showers and thunderstorms. Beyond that, timing of the disturbance would determine the July 28 weather – possibly with the disturbance slow enough for additional showers and storms, then fair weather following that toward the middle of next week.

DAYS 11-15 (JULY 31 – AUGUST 4)

Overall pattern indications a west to northwest flow east of a central US high pressure ridge with a trough of low pressure in Atlantic Canada. Shower/thunderstorm chances would be limited to a couple passing disturbances and most of the time the region would see fair weather, with somewhat variable temperatures but no sustained heat.

80 thoughts on “Monday July 21 2025 Forecast (7:30AM)”

  3. Good morning and thank you TK.
    NOT much of a thunderstorm here. Torrential rain and some thunder and lightning. Although it wasn’t that big a deal, it was still the best thunder storm of the season.

    1. How did your lightning detector work?

      We had nothing here other than a few wind gusts.

      2. I think I wore it out last time. I turned it on and got nothing.
        My lightning display on my phone was showing all sorts of activity. We had a couple of strikes reasonable close as in the a block or 2 away.

        2. Darn.

          We had two close strikes 0.2 and 0.3. It seems that there has been a strike at the same 0.2 area the last three storms.

    1. Same here 5 guesses. Wasn’t even sure that was a real word, it fit so I entered it and VIOLA that was it. I looked it up to see what all the fuzz was about. Tis a real word. 🙂

    2. After three guesses, it was the only word I could think of, so I got it in four.

      The average so far today is 5.5.

      1. Well done. I had nothing for guess two but it was the only option for my fifth guess.

        It’s fun seeing the days average. Thank you

  6. re: WindStorm
    fyi, there are 2 ADDITIONAL movies,
    WindStorm2 and Windstorm3

    ALL Ok in their own right. Not spectacular, but OK. 🙂

    1. btw, I became increasingly MORE irritated with the dubbing and the sounds of the voices used. 🙂 🙂 🙂 I was looking for original German with English subtitles but Amazon Prime didn’t have it available.

      1. I give you a lot of credit. I can’t seem to enjoy subtitles. I get frustrated if lips and words are not 100 percent in sync.

        2. Me too. Even when both the spoken words and text are in English (like closed captioning), I can’t stop myself from reading the subtitles and missing the video!

          1. Exactly.

            And I am not surprised Mrs OS is not a fan. She and I seem to be in sync

    2. It is a beautiful day no matter what.

      Any day I wake up is a beautiful day. You’ll understand when you get to be my age. 🙂

  8. Question. Do lighting rods work? I saw that lighting was suspected for that barn fire in Walpole that killed so many horses. I remember years ago that barns would all have lighting rods but not sure if that is still the case. I’m not sure I ever understood how they work

    1. I believe they do, IF installed correctly.

      Years ago I sort of had one as I grounded the TV antenna via a 3 foot pole banged into the ground. With cable, I no longer needed the TV antenna, so my roof is currently unprotected.

      The idea is that it directs the charge of energy directly into the ground, instead of into/through the roof and thus preventing
      a fire.

      Several years ago, Lightning blew a hole through the roof of a neighbor’s house and started quite a fire. It took more than
      6 months to repair the damage. No one was hurt, luckily.

      1. Wow. Thank heavens no one was hurt.

        My son in law tells me our house being new had a whole house ground. Not sure how that works.

    2. Found this:

      Yes, lightning rods are effective at mitigating damage from lightning strikes. They don’t prevent lightning from striking, but they provide a safe, conductive path for the electrical current to travel to the ground, minimizing the risk of fire, structural damage, or injury to occupants

      2. Awesome. Thank you. I’m remembering more that I’d forgotten as I read your comments. Much appreciated

          1. At the time I was listening to a lot of WBCN. I can’t imagine they didn’t play it. I may very well have heard it and just don’t remember. Oh well.

  12. 75 here, but I am getting a dew point reading of 60.
    That doesn’t sound right???????

      1. Well, then I feel better, except Logan has 55

        I am currently reading 59. My dew point has been extremely accurate, so it gave me pause.

    2. I have 73/63. All stations in the area have 63. My accurite says 61. Heading to an appt so don’t have time to stick the kestrel out

    1. That’s not my favorite day either. But I see some great ones coming up this week:

      July 22: Pi Approximation Day (think date/month format)
      July 23: Vanilla Ice Cream Day (discussed here recently)
      July 24: Pythagorean Theorem Day (7/24/25: 7² + 24² = 25²)

      1. Wasn’t sure you knew or not so took a chance and posted it.

        I check Meso West often. 🙂

  17. Thanks TK. Lovely day. Up in Salem for a golf tournament my son is caddying for an 8 year old who shoots a 42 lol. Wish I could shoot a 42 🙂

    Busy with the new dog and grateful for overall really nice weather. Sure it’s been humid and hot but it tires the dog so happy to have a tired puppy.

  18. SClarke, thanks for sharing the tune that is “sorta-kinda” about Michael Collins.

  19. I picked the wrong time for my long run outdoors today. It was still quite humid. I think that it’ll be drier later.

  20. For those of you who like classical music, besides WCRB I highly recommend WHRB (95.3FM), which is Harvard University radio. It broadcasts an eclectic mix of classical music from 1pm to 6pm, often pieces you’ve never heard of. The wonderful thing is that the announcers (students) often tell you about the history of the pieces being played. And if you like church choir or organ music, you’ll hear plenty of that.

    The only type of music I don’t care for much is jazz. But mornings (until 1pm) on WHRB are devoted to jazz and people say they like the program very much. All music programs are commercial-free and no fund-raisers.

    1. I love WHRB! During Harvard’s two reading/exam periods you often get to binge for a whole day on one composer, then move on to another. (I never thought of studying that way when I was in college, though.)

  21. I really enjoyed today’s entry by TK. The variety of weather that high pressure can provide lacks much discussion because its not sexy or dramatic, but to my small mind its fascinating. For me its of course diurnal temperature swings. Wednesday could push 40 degree swings in a few favored areas…not bad for July.

    Anyway, just wanted to say these atypical discussions are why this blog is such a unique stop the on internet surf map.

    1. Thank you. I really appreciate that you took the time to acknowledge that. The idea came to me at the last moment this morning when I sat down to write, and it just came out easily this time. Not always the case. But I’ll take it when it happens. 🙂

  26. 57 on July 22nd is pretty great. Doesn’t happen too often I can walk out and not sweat lol

  27. Up really early these day with the dog, we’ve had her 1 weeks and she sleeping in the crate from 9-4. I’ll take it. And she’s just about fully potty trained.

    She’s a gift from above that’s for sure.

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