Monday May 18 2026 Forecast (7:33AM)

108 Comments

DAYS 1-5 (MAY 18-22)

A back-door cold front went through the region overnight and sets us up for a dry but cooler day today. The region overall will be a good 10 to 20 degrees lower than yesterday, which was quite a bit above normal, meaning that today will really not be that bad outside, just decidedly “less warm” than Sunday. Coolest readings will be along the east-facing and north-facing shores where wind is directly off the water. We’ll see some clouds scooting west to east across the sky, particularly in northern MA and southern NH, as warmer air is already returning aloft while the surface remains as described above. The much-talked-about summer preview arrives Tuesday with high pressure building to our south, driving warm to hot air and somewhat higher humidity into the region. While it won’t be oppressively humid, by definition, the fact that it’s early season moderate humidity will make it feel a bit worse in a relative sense, since we have not had a chance to adapt as we would by summer. An active breeze from the southwest will be a help, however, and this breeze coming off the Atlantic waters to the south will, of course, keep the South Coast / Cape Cod, and even to the southern portion of the MA South Shore less hot than the remainder of the region that has a pure land breeze. One thing to keep an eye out for later Tuesday is the potential for a few showers and thunderstorms in advance of a pre-frontal trough approaching from the northwest. The greatest chance to see these would be in northern MA and southern NH in the late afternoon to early evening hours. Most areas will remain dry, however, as coverage would be fairly limited. Any of those fade away or move out quickly and we’re left with a fair and very mild night, leading to the summery feeling continuing on Wednesday. The difference this day is that it will be cut off by an approaching and passing cold front, bringing more clouds and a better chance of showers and thunderstorms to the region. I still have to refine the expecting timing of this front in the next couple of updates, but for now I am leaning toward it being a quick enough passage that the greatest shower and thunderstorm chance may be from the I-95 belt southeastward. This will lead to fair and cooler weather Thursday and Friday as high pressure builds into the region.

TODAY: Mostly sunny to partly cloudy. Highs 62-69 coast, 70-77 inland. Wind shifting to NE 5-15 MPH.

TONIGHT: Partly cloudy. Lows 52-59. Wind variable up to 10 MPH becoming SW.

TUESDAY: Mostly sunny to partly cloudy. Slight chance of a late-day shower or thunderstorm favoring northern MA and southern NH. Highs 69-76 Islands / Cape Cod, 77-84 southeastern CT and southern RI to MA South Shore (southern portion), 85-92 elsewhere. Wind SW 5-15 MPH, higher gusts possible.

TUESDAY NIGHT: Partly cloudy. Patchy fog. Lows 55-62. Wind SW up to 10 MPH.

WEDNESDAY: Variably cloudy. Showers and thunderstorm potential from late morning through afternoon, with highest thunderstorm potential I-95 belt southeastward. Highs 65-72 Cape Cod / Islands, 73-80 southeastern CT and southern RI to MA South Shore, 81-88 elsewhere. Wind SW increasing to 10-20 MPH, higher gusts possible, especially near any storms.

WEDNESDAY NIGHT: Clearing. Lows 48-55. Wind NW 5-15 MPH.

THURSDAY: Partly cloudy. Highs 63-70. Wind NW 5-15 MPH.

THURSDAY NIGHT: Partly cloudy. Lows 43-50. Wind NW to N up to 10 MPH.

FRIDAY: Partly sunny. Highs 62-69. Wind N to NE up to 10 MPH.

DAYS 6-10 (MAY 23-27)

Memorial Day Weekend (May 23-25) looks cooler with high pressure to the north. Watching low pressure to the south and for now I continues to lean toward the greatest potential for wet weather to be later Saturday into Sunday with improvement for Memorial Day. Still a high degree of uncertainty on this outlook, so follow updates! An upper low hangs around with cooler weather and a few pop up showers possible into the middle of next week.

DAYS 11-15 (MAY 28 – JUNE 1)

Leaning cooler then average, drier overall, but not without at least a brief unsettled threat or two.

108 thoughts on “Monday May 18 2026 Forecast (7:33AM)”

  2. Good morning and thank you TK

    66 here up from 61

    Ocean: 53

    Wordle: 3

    A wee bit of an over achiever yesterday. Logan made 90 while we made 87 here. Can you say transpiration? At least it was fairly dry yesterday. Ac installs today.

    High temperature here today depends on how strong the East wind gets. Ocean is still 53 which can still supply a good deal of cooling. I’ll place my o/u at an optimistic 70.

  5. Wow!!! Just hit my o/o as we are now at 70.
    63 at the airport. Now I am wondering if I am getting some sun on the sensor. I’ll know soon enough. 🙂

  6. I just checked my sensor and it is CLEARLY in the shade.

    Now reading 74 here. Still seems high, but that is what it is reading in the shade.

  7. Tonight looks interesting to me, especially eastern areas.

    Could see that still onshore component, SE wind, bringing things down into the mid-upper 50s near sunset.

    But, tremendous warm air advection sets in tonight.

    If the wind comes around to SW after say midnight, I believe the temps are rising to the mid 60s by sunrise.

  10. Wordle: 4

    I’m happy with that, however, I was thrown off by a 6 letter word that I knew of and didn’t know this was a word without that last letter.

    But, I’ll take it !!

  12. I remember I said yesterday I was going to ask someone what word he mentioned using in wordle. Just can’t remember who 🙄

    SClarke??

    2. Ah yes. As a hobbiest woodworker, I’m familiar with “inlay”. Yesterday I tried “onlay” and it’s a word. You can get it on a tooth!

  13. Just 70 here now. I think we are beginning to really feel the effects of that EAST wind.

    Logan is 64 with ENE wind at 15
    Norwood is 77 with ESE at 3 HUGE difference!!!!

    1. Fascinating contrast with Mt Washington which has a strong SW wind and the summit temp is warming.

      Of course, this NE wind is the effect of a weak bubble of high pressure off to our northeast.

      But that warm air is already returning aloft, neat to see how long the cooling hangs in at the coast, probably at least to near sunset.

    1. Sounds about right. We shall see if it is upgraded to slight tomorrow or Wednesday AM.

  15. I think, with maybe a year exception for when, one of our daughter’s were infants, we have camped every Memorial Day Weekend. So, perhaps 22 of the last 25 years. Also Covid year.

    And, the majority of time its been in the 50s, cool, sometimes chilly and raw, occasionally rainy. Certainly not, the unofficial start to summer.

    And I can see whats coming in the models.

    Drought, leave it out. I can see it ending up fairly dry but that will still leave high pressure in the Gulf of Maine, NE or E wind, probably at least some stratus and I see a lot of 50s being projected for highs.

    So frustrating.

    Not looking for 80s and 90s.

    But the avg of 70F would be nice, but, I don’t know if we’ll end up close to that, at least east of Worcester.

  16. Down to 68 here.

    81 at Norwood. Not sure we expected those reading so close to Boston.

    1. Its warm just above the shallow eastern Mass marine layer.

      Full sun in southern areas, not the strongest onshore flow and warm airmass above.

    3. Well, we overachieved a good 2-5F both days this weekend and if the models are showing 87-92F, I can only imagine where we might end up inland from that indirect SW seabreeze.

        1. Depends how much southerly component the wind has. After all it’s only May 18th. The more Southerly component, the lower the temperature will be.

      1. According to the 18Z RRFSA, warm front gets to Boston Around 6-7 PM With Dps rising SIGNIFICANTLY!!!!
        But no appreciable rise in temperature at that time.

  21. Out temperature has been hovering around 70, sometimes 71 and sometimes 69 in addition to 70. I was just out. Here it is absolutely BEAUTIFUL!!! the is a slightly cool breeze while the sun is BLAZING HOT!!!!

    Just lugged a VERY heavy New AC (still in the box) from our front door downstairs up to the 2nd floor where I will install it. Even with a super duper hand truck/dolly type thing it took a lot of energy to move that thing up 18 stairs. Now it is sitting under the window where it will be installed.

    I am actually worried about tomorrow. My wife didn’t fare so well yesterday and that was nothing compared to what tomorrow will be. But we will have AC as long as we don’t lose power. Last Summer we lost power on the 102 degree day! That was lovely. We were about to move to a motel/hotel when it finally came on.

    I HAT ETHE HHHH

  22. A bunch of 90s showing up in Western MA and CT.
    84 as nearby as Norwood and Mansfield.

    It’s even 90 up at Springfield, VT.

    I see a 97 in Maryland.

    I fear tomorrow will OVER ACHIEVE yet again. I sure hope not, but I am NOT liking what I see.

  23. Yesterday May 17, Boston (Logan) had their first 80F and 90F both in the same day.

    They definitely overachieved (90) to say the least as the original forecast high was supposed to be around 85F iirc.

    I expect overachievements again tomorrow and Wednesday…Y-U-C-K!!!

    1. Wednesday may under-achieve with more cloudiness and faster timing.

        1. It’ll be a bit rough. The breeze will help. Certainly not the first time we’ve had a hot day in April or May. 🙂 Even March.

          I’d love it if media was less dramatic about it, but we know that won’t happen.

          Speaking of, the anchor on WBZ radio was complaining that the weather was nice today because it was Monday. Stupid comment.

  25. 5 global models have 5 different solutions for Memorial Day Weekend. Far, far too soon for definitive answers there.

  26. I would be curious if the upcoming El Niño will be influencing summer temperatures (for the worst).

    1. Probably not. Too many other factors involved.

      Notable hot summers attached to El Nino years were 1980, 1983, and 1988. Most certainly does not happen every time.

      I do not thing we’re in for a particularly hot summer, to be honest.

  27. Current temperatures:

    Boston: 64
    Quincy (here): 83

    All I can say is…interesting.

    2. Where in Quincy are you. Beginning of rt. 53? or elsewhere?
      Wherever you are, I’ll bet anything at Wollaston beach it’s in the 60s.

  29. Thanks, TK!

    88 the high today. It was 91 yesterday.

    84/58 down.

    Rolled back the moonroof and blasted “Runnin’ Down A Dream” by Tom Petty and the Heartbreakers rolling on down Rt. 495 heading home this afternoon. GREAT car song!

    I love nearly all sports, but, in my opinion, there’s nothing better than a Game 7 of an NHL playoff series: Canadiens and Sabres. It’s been a great series. Looking forward to its finale tonight at 7:30.

  31. I think we’re about ready to jump temp wise.

    Plymouth’s been warmer for hours on a S wind, but now it’s SSW or SW. The Cape is over to SW, so this boundary is curved on the south shore.

    Our SE wind just saw a temp jump to 70F, so, that warm air is circling us and slowly moved in.

    Wouldn’t he surprised if we jump to 75-80F very soon.

    1. Yup.

      Jumped to 75F.

      S wind at airport by I’m out and about and it’s SW by 139. Neat.

      Logan, here it comes. 🙂

  32. Eric F going with 96F tomorrow in Boston.

    If the wind is WSW, I agree, again based on the overachievement this weekend.

    And the 500 mb heights and 850 mb temps are higher and warmer, respectively, tomorrow than they were Sunday.

    And we just had another sunny day today to evaporate even more moisture from a fairly dry ground, as it is.

      1. I know tomorrow is tough for some, but I’ll take it over what I think might happen this weekend.

        I’m laughing at the mid 60s some tv Mets have for Saturday. I’d be thrilled with that. I think it’s probably destined for 53F.

        1. The weather has its own mind. And I love that. It’s paying for the AC that’s killing me.

  35. If Logan’s stubborn micro climate holds for a couple hours, then their high for the day may be 73-77F.

    But if that warm front comes through the next 30 mins, they might get to 78-82F.

  36. Thank goodness we can come here and focus on weather.

    Another tragedy in San Diego. Horrific.

  37. We had sea breeze storms down here in Sarasota awhile ago. We had a high of 94°. I’m sending heat up to the Wood House weather area for tomorrow. My area in Warwick jumped up to 81° when the warm front went through.
    Hopefully the people up there do ok if they have health related heat issues.

  38. I have recently discovered that Quincy can be considerably milder than Boston with a SE wind. Today was a perfect example. Earlier this spring TK pointed that out to me here on the blog.

    With a NE wind, both locations are chilly.

  39. According to Eric, the highest temperature ever recorded in Boston for May is 97F.

    Could that be broken come tomorrow? Hmmm.

  40. Sure would love for Saturday day to be rain free & comes in at night . Two major jobs going this weekend.

    1. You may be in luck.

      Right now, Friday’s a dry lock. Saturday looks dry in the eastern areas until late-day.

  41. I don’t know how many have been to Hull (Nantasket beach), but if you stay on that main road and take it all the way to the end, you come to what I believe is called Hull gut.

    It’s amazing out there and you get an awesome view of the harbor islands, Boston and the planes coming into Logan, which isn’t far away.

    It’s 69F in Hull with a SW wind and it’s 61F at the weather ob, armpit of America (Logan) with a NE wind. Even 16 NM east of Logan at the harbor buoy, the wind is around to the south !!

    Incredible.

    1. Mac and I stayed in Hull a few winters at a hotel special. I know exactly what you mean

    3. It is indeed called Hull gut. It is part of a little drive I tend to take when I want to get air.

  42. Two things: Tom was right on this morning – as the sunset the low level moisture moved right in along the coast off the ocean. Splendid view of the moon and Venus tonight. Next door neighbors

  43. In the warm air been that way for 3 hours or so.
    What kind of launching pad will we have for tomorrow. Holding at 72 now, dp 61

  45. Coyotes must be active, our dog is barking away and thus, we’re awake 🙂

    What a warm night !!

    And it’s 57F atop Mt Washington and climbing.

    With manageable humidity, the temps away from the south coast and Cape tomorrow should be amazing.

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