Lexington Weather

Current Conditions [‒] Current Conditions [+]

78.3°F Colder than last hour.

25.7°C

Very Muggy

Clear

Tonight: Lo 70 °F

Monday: Hi 91 °F

Dew Point: 72.0°F Increased 0.2°F since last hour .

Humidity: 81% Increased 5.0% since last hour.

Barometer: 29.94 in Rising 0.02 inHg/hr

1014 mb

Rain Rate: 0.00 in/hr

Rain Today: 0.05 in

Rain Saturday: 0.00 in

Visibility: 10 miles

Wind:

Now: Calm

Avg: Calm

Gusts: 0 mph

OTHER PERSONAL WEATHER STATIONS

Alerts / Advisories [‒] Alerts / Advisories [+]

Southeast Middlesex County, MA - Extreme Heat Warning
- SEE ALL NEARBY ALERTS -

NWS Weather Forecast -
Tonight, Monday, & Monday Night through Sunday

Issued by:
National Weather Service Boston / Norton, MA
Point Forecast Updated Sun Jun 22, 2025 6:51pm EDT

Overview:

Dangerous heat and humidity through early next week peaks on Tuesday. The heat begins to ease on Wednesday then turning cooler for the end of the week into next weekend with daily chances of showers and possibly a few thunderstorms.

Extreme Heat Warning

Tonight:

Partly Cloudy then Patchy Fog

Lo 70 °F

Patchy fog between 4am and 5am. Partly cloudy, with a low around 70. Heat index values as high as 95. Northwest wind 2 to 9 mph.

Monday:

Patchy Fog then Mostly Sunny

Hi 91 °F

Patchy fog before 7am. Mostly sunny, with a high near 91. East wind 1 to 7 mph.

Monday Night:

Mostly Clear

Lo 74 °F

Mostly clear, with a low around 74. South wind around 7 mph.

Tuesday:

Sunny

Hi 100 °F

Sunny, with a high near 100. Heat index values as high as 108. West wind 6 to 9 mph.

Tuesday Night:

Mostly Clear

Lo 77 °F

Mostly clear, with a low around 77. Northwest wind around 8 mph.

Wednesday:

Mostly Sunny

Hi 89 °F

Mostly sunny, with a high near 89. Northeast wind around 7 mph.

Wednesday Night:

Partly Cloudy then Slight Chance Rain Showers

Lo 65 °F

A slight chance of rain showers after 1am. Partly cloudy, with a low around 65. East wind around 6 mph.

Thursday:

Chance Rain Showers

Hi 76 °F

A chance of rain showers before 2pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 76. East wind 5 to 8 mph. Chance of precipitation is 40%.

Thursday Night:

Chance Rain Showers

Lo 60 °F

A chance of rain showers. Mostly cloudy, with a low around 60. Northeast wind around 7 mph. Chance of precipitation is 40%.

Friday:

Chance Rain Showers

Hi 71 °F

A chance of rain showers. Mostly cloudy, with a high near 71. East wind 5 to 8 mph. Chance of precipitation is 50%.

Friday Night:

Rain Showers Likely

Lo 60 °F

Rain showers likely. Mostly cloudy, with a low around 60. East wind around 7 mph. Chance of precipitation is 60%.

Saturday:

Rain Showers Likely

Hi 72 °F

Rain showers likely. Mostly cloudy, with a high near 72. East wind around 8 mph. Chance of precipitation is 60%.

Saturday Night:

Chance Rain Showers

Lo 62 °F

A chance of rain showers before 5am, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 62. Northeast wind 5 to 8 mph. Chance of precipitation is 40%.

Sunday:

Chance Showers And T-Storms

Hi 78 °F

Sunday: Chance Showers And Thunderstorms

A chance of showers and thunderstorms. Partly sunny, with a high near 78. Northwest wind 5 to 8 mph.

FULL FORECAST

NWS Hourly Forecast -
Tonight 11pm through Tue 10am

Issued by:
National Weather Service Boston / Norton, MA
Updated Sun Jun 22, 2025 6:51pm EDT

11:00pm

Partly Cloudy

78°F
Dew Pt 71°F
Wind from NW

NW 6 mph
Precip: 0%

Mon
12:00am

Mostly Cloudy

76°F
Dew Pt 70°F
Wind from NW

NW 6 mph
Precip: 0%

Mon
1:00am

Partly Cloudy

75°F
Dew Pt 69°F
Wind from N

N 5 mph
Precip: 0%

Mon
2:00am

Partly Cloudy

73°F
Dew Pt 69°F
Wind from NW

NW 5 mph
Precip: 0%

Mon
3:00am

Mostly Clear

72°F
Dew Pt 68°F
Wind from NW

NW 3 mph
Precip: 0%

Mon
4:00am

Patchy Fog

70°F
Dew Pt 68°F
Wind from NW

NW 3 mph
Precip: 0%

Mon
5:00am

Partly Cloudy

70°F
Dew Pt 67°F
Wind from NW

NW 2 mph
Precip: 0%

Mon
6:00am

Patchy Fog

71°F
Dew Pt 68°F
Wind from NW

NW 3 mph
Precip: 0%

Mon
7:00am

Mostly Sunny

73°F
Dew Pt 68°F
Wind from N

N 2 mph
Precip: 0%

Mon
8:00am

Mostly Sunny

76°F
Dew Pt 68°F
Wind from NE

NE 3 mph
Precip: 0%

Mon
9:00am

Mostly Sunny

78°F
Dew Pt 67°F
Wind from NE

NE 2 mph
Precip: 0%

Mon
10:00am

Mostly Sunny

82°F
Dew Pt 67°F
Heat Index: 85°F
Wind from NE

NE 1 mph
Precip: 1%

Mon
11:00am

Mostly Sunny

84°F
Dew Pt 67°F
Heat Index: 87°F
Wind from S

S 1 mph
Precip: 1%

Mon
12:00pm

Sunny

87°F
Dew Pt 67°F
Heat Index: 90°F
Wind from S

S 2 mph
Precip: 1%

Mon
1:00pm

Sunny

89°F
Dew Pt 67°F
Heat Index: 92°F
Wind from SE

SE 5 mph
Precip: 1%

Mon
2:00pm

Sunny

90°F
Dew Pt 67°F
Heat Index: 93°F
Wind from SE

SE 6 mph
Precip: 2%

Mon
3:00pm

Sunny

90°F
Dew Pt 67°F
Heat Index: 93°F
Wind from SE

SE 6 mph
Precip: 2%

Mon
4:00pm

Sunny

90°F
Dew Pt 66°F
Heat Index: 93°F
Wind from SE

SE 6 mph
Precip: 3%

Mon
5:00pm

Sunny

89°F
Dew Pt 66°F
Heat Index: 92°F
Wind from SE

SE 7 mph
Precip: 4%

Mon
6:00pm

Mostly Clear

87°F
Dew Pt 66°F
Heat Index: 89°F
Wind from SE

SE 7 mph
Precip: 4%

Mon
7:00pm

Mostly Clear

86°F
Dew Pt 67°F
Heat Index: 89°F
Wind from SE

SE 7 mph
Precip: 3%

Mon
8:00pm

Mostly Clear

84°F
Dew Pt 68°F
Heat Index: 87°F
Wind from S

S 6 mph
Precip: 3%

Mon
9:00pm

Mostly Clear

82°F
Dew Pt 69°F
Heat Index: 85°F
Wind from S

S 6 mph
Precip: 3%

Mon
10:00pm

Mostly Clear

80°F
Dew Pt 69°F
Heat Index: 83°F
Wind from S

S 7 mph
Precip: 2%

Mon
11:00pm

Mostly Clear

78°F
Dew Pt 70°F
Wind from SW

SW 7 mph
Precip: 1%

Tue
12:00am

Mostly Clear

77°F
Dew Pt 70°F
Wind from SW

SW 7 mph
Precip: 1%

Tue
1:00am

Mostly Clear

77°F
Dew Pt 70°F
Wind from SW

SW 7 mph
Precip: 1%

Tue
2:00am

Mostly Clear

76°F
Dew Pt 70°F
Wind from SW

SW 7 mph
Precip: 1%

Tue
3:00am

Mostly Clear

75°F
Dew Pt 70°F
Wind from SW

SW 7 mph
Precip: 1%

Tue
4:00am

Mostly Clear

74°F
Dew Pt 70°F
Wind from SW

SW 6 mph
Precip: 0%

Tue
5:00am

Mostly Clear

74°F
Dew Pt 70°F
Wind from SW

SW 6 mph
Precip: 0%

Tue
6:00am

Sunny

76°F
Dew Pt 71°F
Wind from W

W 6 mph
Precip: 0%

Tue
7:00am

Sunny

79°F
Dew Pt 72°F
Wind from W

W 7 mph
Precip: 0%

Tue
8:00am

Sunny

83°F
Dew Pt 72°F
Heat Index: 88°F
Wind from W

W 7 mph
Precip: 0%

Tue
9:00am

Sunny

86°F
Dew Pt 72°F
Heat Index: 92°F
Wind from W

W 7 mph
Precip: 0%

Tue
10:00am

Sunny

90°F
Dew Pt 72°F
Heat Index: 97°F
Wind from W

W 7 mph
Precip: 0%

VIEW ON NWS WEB SITE

FORECAST DISCUSSION

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 222325
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
725 PM EDT Sun Jun 22 2025

.SYNOPSIS...
Dangerous heat and humidity through early next week peaks on 
Tuesday. The heat begins to ease on Wednesday then turning cooler 
for the end of the week into next weekend with daily chances of 
showers and possibly a few thunderstorms.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Tonight:

Key Point

* Warm and humid with lows around 70F

Substantial height rises should cap the atmosphere off for the 
remainder of the afternoon and evening, even with 3000-4000 J/kg of 
SBCAPE.  There could be a few weak showers and a rumble or two of 
thunder over the eastern waters this evening, where strong westerly 
winds inland converge with strong southerly winds over the waters. 
Instability is much lower over the water, so its unlikely that 
anything that develops will become severe.  

Temperatures this afternoon have quickly jumped into the upper 80s 
to low 90s behind the showers from this morning. Temperatures could 
climb further into the mid-90s this afternoon before peak diurnal 
heating ends.  There is little relief from the heat tonight, as low 
temperatures only drop into the upper 60s to low 70s.  There could 
be some patchy fog overnight as dewpoints stay near 70F and winds 
become light.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Key Points

* Dangerous Heat and humidity with heat index values as high as
  115F

* Not much heat relief overnight with lows still near 70F

Tomorrow:

Dangerous heat and humidity continues tomorrow as the upper-
level ridge and heat dome continue to build in southern New 
England. 850mb temperatures will warm to around 20C, which 
will translate to surface temperatures in the upper 90s to even 
near 100F in the CT River Valley. With dewpoints still near 
70F, the heat index, or feels-like temperature, will be between
105F and 115F across western Massachusetts and all of 
Connecticut. Further east, the light pressure gradient and hot 
temperatures will lead to strong sea breezes pushing inland 
across eastern Massachusetts and Rhode Island, resulting in high
temperatures in the low to mid-90s and heat index values 
between 95F and 105F. The only place to escape the heat 
tomorrow will be Cape Cod and the Islands, where high 
temperatures will range from the mid-70s to the low 80s. Skies 
remain mostly sunny with dry conditions as the ridge continues 
to suppress any precip chances.

Tomorrow night: 

A significant part of why a heat wave is so dangerous is that 
overnight temperatures offer little relief from the heat and 
humidity.  Temperatures at midnight on Tuesday will still be in the 
upper 70s to low 80s, and overnight lows will only drop to the low 
to mid-70s.  Dewpoints remain in the 70s overnight, which will keep 
that tropical feel to the airmass overnight.  With southerly flow, 
there could be more widespread low status and dense fog across the 
Cape and Islands and possibly into southeastern Massachusetts and 
Rhode Island.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Key Messages: 

* Peak of the heat will be on Tuesday with dangerously high heat 
  indices 100 to 110 degrees

* Heat diminishes Wed but still hot away from the coast, then 
  cooler for late in the week and weekend

* A few showers and t-storms possible Wed with locally heavy 
  downpours

* Daily chances of showers and perhaps a few t-storms Thu through Sun

The dangerous heat peaks on Tue as anomalous mid level ridge builds 
over the mid Atlc region. 850 mb temps around 22C and 925 mb 
temps up to 28C are about as high as you will see in SNE. This
coupled with full sunshine and westerly flow will result in 
widespread high temps in the upper 90s and low 100s, with temps 
around 90 on Cape Cod and south coast beaches. Dewpoints will be
in the lower 70s in the morning, but well mixed boundary layer 
may allow dewpoints to fall into the upper 60s in some locations
during peak heating. Still expect heat indices peaking at 
100-110F. It will be a rather warm night Tue night with temps 
above 80 through midnight away from the south coast before 
dropping to mid 70s by daybreak.

The mid level ridge begins to break down Wednesday as polar jet 
shifts southward. Slight cooling aloft and wind shift to E-NE will 
take the edge off the heat somewhat, especially along the coast as 
sea-breezes develop. But still a hot day with highs low-mid 
90s inland and mid-upper 80s along the coast, cooler Cape/Islands. 
Dewpoints will be dropping through the 60s which will keep heat 
indices in check somewhat. Peak heat indices will be 95-100F across 
CT and possibly into Springfield where heat advisories may be 
needed. Weak boundary will be hanging around SNE and we have 
instability with CAPES 500-1500 J/Kg along with elevated PWAT plume 
so can't rule out a few showers and t-storms. PWATs near 2 inches so 
any showers or storms could contain locally heavy downpours. 

Then true relief from the heat arrives Thursday through Sunday as 
weak surface boundary settles south of New Eng with easterly flow 
developing along with much cooler 925 mb temps. Temps will average 
below normal with highs mostly in the 70s but it is not out of the 
question a few days could be even cooler in some locations. There 
will be daily chances of showers through the period as deep moisture 
plume persists over the region with elevated PWATs 1.5 to 2 inches. 
There is minimal to no surface instability during this time so 
severe weather is not expected but can't rule out a few t-storms 
given some elevated instability in place.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

Low - less than 30 percent. 
Moderate - 30 to 60 percent. 
High - greater than 60 percent.

00z TAF Update:

Tonight: High confidence. 

Mainly VFR, though possible fog near the south coast, cape and
Islands airports and interior valleys. Winds become light NW, 
with N to NE winds developing along the eastern coast. 

Monday: High confidence. 

VFR. Light north winds become S and increase to around 5-10 kt
for most

Monday Night: Moderate Confidence

Light southerly winds may lead to more widespread low status and
fog overnight for the south coast including the Cape and
Islands.

KBOS Terminal...High confidence in TAF. 

VFR. Gusty W winds to 25-30 kt this afternoon. Low chance for a
isolated shower this afternoon. Light north winds tonight

KBDL Terminal...High confidence in TAF. 

VFR. Gusty W winds this afternoon. Light and variable winds
tonight.

Outlook /Tuesday through Friday/... 

Tuesday through Tuesday Night: VFR. 

Wednesday: VFR. Slight chance SHRA.

Wednesday Night: VFR. Slight chance SHRA, isolated TSRA.

Thursday: Mainly VFR, with areas MVFR possible. Chance SHRA,
isolated TSRA.

Thursday Night: Mainly VFR, with areas IFR possible. Chance
SHRA.

Friday: Mainly VFR, with local IFR possible. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

Low - less than 30 percent. 
Medium - 30 to 60 percent. 
High - greater than 60 percent.

Through Tomorrow night: High confidence.

Gusty winds this afternoon quickly diminish this evening turning
from west to north. Winds gradually turn south tomorrow and 
remain light under 10 knots. Marine fog possible tonight, but 
more likely tomorrow night with southerly flow. 

Outlook /Tuesday through Friday/...

Tuesday through Wednesday: Winds less than 25 kt. 

Wednesday Night: Winds less than 25 kt. Slight chance of rain
showers. 

Thursday: Winds less than 25 kt. Slight chance of rain showers,
isolated thunderstorms. 

Thursday Night through Friday: Winds less than 25 kt. Chance of
rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Extreme Heat Warning until 8 PM EDT Tuesday for CTZ002>004.
MA...Extreme Heat Warning until 8 PM EDT Tuesday for MAZ003>007-
     010>021-026.
     Heat Advisory until 8 PM EDT Tuesday for MAZ002-008-009.
RI...Extreme Heat Warning until 8 PM EDT Tuesday for RIZ001>007.
     Air Quality Alert until 11 PM EDT this evening for RIZ006>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for 
     ANZ232>235-237-254.
     Small Craft Advisory until 2 AM EDT Monday for ANZ255-256.

&&

$$

SYNOPSIS...KJC/KP
NEAR TERM...KP
SHORT TERM...KP
LONG TERM...KJC
AVIATION...Frank/KP
MARINE...KJC/KP

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