Lexington, Massachusetts, USA
35.1°F
1.7°C
Cold
Mostly cloudy
This Afternoon: Hi 81 °F
Tonight: Lo 67 °F
Dew Point:
32.4°F
Humidity: 90%
UV Index: 0.0 None
Barometer:
mb
Rain Rate: 0.00 in/hr
Rain Today: 0.01 in
Rain Monday: 0.00 in
Visibility: 10 miles
Wind:
Now: Calm
Avg: Calm
Gusts: 0 mph
Issued by:
National Weather Service Boston / Norton, MA
Point Forecast Updated Tue Jul 21, 2026 2:32pm EDT
- Widespread showers and thunderstorms this afternoon and evening.
- Another round of showers and thunderstorms possible Wednesday afternoon
- Seasonable temperatures and comfortable humidity returns with dry conditions for the second half of the week.
Chance Showers And T-Storms
Hi 81 °F
A chance of rain showers before 5pm, then a chance of showers and thunderstorms. Cloudy, with a high near 81. South wind around 13 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.
Showers And T-Storms
Lo 67 °F
Showers and thunderstorms before 4am, then a chance of rain showers and patchy fog between 4am and 5am, then patchy fog and a chance of showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy, with a low around 67. South wind 8 to 12 mph, with gusts as high as 24 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.
Patchy Fog then Chance Showers And T-Storms
Hi 85 °F
Patchy fog and a chance of showers and thunderstorms before 11am, then a chance of showers and thunderstorms between 11am and 5pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 85. Southwest wind around 12 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
Chance Showers And T-Storms then Partly Cloudy
Lo 60 °F
A chance of showers and thunderstorms before 11pm. Partly cloudy, with a low around 60. West wind 5 to 9 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
Sunny
Hi 80 °F
Sunny, with a high near 80. Northwest wind around 7 mph.
Clear
Lo 59 °F
Clear, with a low around 59. West wind around 5 mph.
Sunny
Hi 82 °F
Sunny, with a high near 82. North wind 2 to 8 mph.
Mostly Clear
Lo 60 °F
Mostly clear, with a low around 60. South wind 2 to 7 mph.
Sunny
Hi 79 °F
Sunny, with a high near 79. Northeast wind 2 to 8 mph.
Partly Cloudy
Lo 61 °F
Partly cloudy, with a low around 61. Northeast wind 2 to 7 mph.
Mostly Sunny
Hi 81 °F
Mostly sunny, with a high near 81. East wind 2 to 7 mph.
Partly Cloudy
Lo 63 °F
Partly cloudy, with a low around 63. South wind around 6 mph.
Chance Showers And T-Storms
Hi 84 °F
A slight chance of rain showers between 7am and 2pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 84. Southwest wind 3 to 8 mph. Chance of precipitation is 50%.
Chance Showers And T-Storms
Lo 64 °F
A chance of showers and thunderstorms before 2am, then a slight chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Southwest wind around 6 mph.
Issued by:
National Weather Service Boston / Norton, MA
Updated Tue Jul 21, 2026 2:32pm EDT

S 13 mph
S 13 mph
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S 10 mph
S 9 mph
S 9 mph
S 8 mph
S 8 mph
SW 8 mph
S 8 mph
S 8 mph
S 8 mph
S 9 mph
S 9 mph
SW 9 mph
SW 9 mph
SW 9 mph
SW 9 mph
SW 9 mph
SW 10 mph
SW 10 mph
SW 10 mph
SW 12 mph
SW 12 mph
SW 10 mph
SW 10 mph
SW 9 mph
SW 8 mph
W 7 mph
W 7 mph
W 7 mph
W 6 mph
W 6 mph
W 5 mph
W 5 mph
W 6 mph
000
FXUS61 KBOX 211822
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
222 PM EDT Tue Jul 21 2026
.WHAT HAS CHANGED...
No significant changes sine last forecast update.
&&
.KEY MESSAGES...
- Widespread showers and thunderstorms this afternoon and evening.
- Another round of showers and thunderstorms possible Wednesday
afternoon
- Seasonable temperatures and comfortable humidity returns with
dry conditions for the second half of the week.
&&
.DISCUSSION...
KEY MESSAGE 1... Widespread showers and thunderstorms this afternoon
and evening.
Shortwave energy moving over the northeast will support a period of
widespread showers and thunderstorms this afternoon and evening.
Moderate instability to the tune of 750-1000 J/kg of MUPCAPE and
high PWATs near 2" will support isolated to scattered areas of
torrential rainfall with embedded thunder and widespread
moderate showers elsewhere. There is a low-risk for some storms
to be strong to severe with potentially damaging wind gusts.
Relatively strong wind fields by July standards should mitigate
the overall flooding threat with mid-level flow around 30
knots supporting faster moving storms. However, we'll be on the
looking for any training areas of torrential rain that could
lead to flooding in urban or poor drainage areas. Expect the
greatest shower and thunderstorm activity across eastern MA and
RI between roughly 5PM and 1AM. Shower and thunderstorm
activity should wane overnight as stronger forcing shifts east
of southern New England.
KEY MESSAGE 2... Another round of showers and thunderstorms
possible Wednesday afternoon
Showers and thunderstorms return tomorrow afternoon with instability
increasing in response to increased moisture. Dewpoints in the low
to mid 70s may support SBCAPE values up to 1500 J/kg. Instability
will depend greatly on how much heating we get early tomorrow. The
amount of heating we get early will depend on how much clearing
occurs between tonight and tomorrow morning. 12Z HREF guidance
suggests enough heating to support showers and thunderstorms across
eastern CT, MA, and RI during the mid-afternoon hours between 4 and
8PM. Shear will be modest with roughly 20-25 knots in the 0-6km
layer. Overall severe threat is low, but a few isolated strong
to severe storms will be possible as a cold front pushes through
the region. A cooler/drier air mass settles over the region
Wednesday night into Thursday with dewpoints falling to the
upper 50s/low 60s. This should support a more comfortable day on
Thursday.
KEY MESSAGE 3...Seasonable temperatures and comfortable
humidity returns with dry conditions for the second half of the
week.
As the cold front finally pushes offshore Thursday, the upper level
trough over Quebec also pushes northeast into the Labrador Sea and a
high pressure system begins to build over the Great Lakes. A drier
airmass will be ushered into southern New England Thursday in the
wake of the cold front, with dewpoints dropping into the mid to
upper 50s, leading to much more comfortable feeling temperatures.
925mb and 850mb temperatures drop to near 16C and 10C, respectively,
for the second half of the week, but intense sunlight and mostly
clear skies will keep temperatures seasonable... roughly 80-85
through at least Sunday. Rain chances don't look to make a return
until later Sunday evening, possible Sunday night into Monday, as
south-southwesterly flow becomes more dominant and dewpoints begin
to increase.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
18Z TAF Update:
Through 00Z...Moderate confidence.
Scattered showers from 18-21Z increasing in coverage and
intensity between 21-00Z with -TSRA possible. VFR ceilings/vsbys
deteriorating to MVFR. Steady south winds from 10-15 knots with
gusts to 25 knots.
Tonight...Moderate confidence.
TSRA/+TSRA mainly between 00-03Z with ceilings falling to
MVFR/IFR levels. Expect SHRA/TSRA to wane between 03-06Z. IFR
conditions prevail thereafter with south/southwest winds around
10 knots.
Tomorrow... Moderate confidence.
IFR ceilings scatter out to VFR across the interior with some
IFR/MVFR ceilings lingering over The Cape/Islands terminals into
the afternoon. Showers and thunderstorms possible after 18Z,
mainly across eastern MA and RI. Low confidence in intensity and
coverage of showers. Southwest winds 10-15 knots with some gusts
to 25 knots possible.
Tomorrow Night...High Confidence.
Any afternoon SHRA/TSRA wanes after 00Z with VFR conditions
thereafter. Southwest winds shift to light out of hte northwest
from 5-10 knots behind a passing cold front. Expect the wind
shift around 06Z Thursday.
KBOS Terminal...Moderate confidence in TAF.
Lower confidence in shower coverage and intensity between
18-21Z. Confidence in SHRA increases around 21Z with moderate to
high confidence in TSRA near the terminal between 00-03Z, though
TSRA could be observed as early as 21-00Z.
KBDL Terminal...Moderate confidence in TAF.
Highest chances for TSRA between 21-00Z.
Outlook /Thursday through Sunday/...
VFR.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight through Wednesday night
Gusty south/southwest winds over the coastal waters tonight with
near, but slightly below gale force gusts expected. Small Craft
Advisory remains in effect for 25-30 knot wind gusts and 6-10
foot seas over the outer marine zones. Highest waves expected
over the south coastal waters. Showers and thunderstorms
expected this afternoon and overnight.
Strongest winds come down to 20-25 knots for tomorrow with
continued steady 15-20 knot southwest flow during the day
tomorrow. A cold front crosses the waters tomorrow night
resulting in a wind shift to t he northwest. This will be
followed by more tranquil conditions to end the week.
Outlook /Thursday through Sunday/...
Thursday: Winds less than 25 kt. Areas of rough seas. Chance of
rain showers, slight chance of thunderstorms.
Thursday Night: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.
Friday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Saturday through Saturday Night: Winds less than 25 kt. Slight
chance of rain showers.
Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Surf Advisory from 6 AM Wednesday to 8 PM EDT Thursday
for MAZ020>024.
RI...High Surf Advisory from 6 AM Wednesday to 8 PM EDT Thursday
for RIZ006>008.
MARINE...Small Craft Advisory from 8 PM this evening to 8 PM EDT
Wednesday for ANZ231>235-237-250-254>256.
&&
$$
DISCUSSION...McMinn/RM
AVIATION...RM
MARINE...McMinn/RM
Radar images courtesy Weather Underground / Intellicast.
UV Index forecast high for today: 7 High
Current (Measured): 0.0 None
Note: Rain measured automatically by weather station. Rain totals do not necessarily include melted frozen precipitation.
For more accurate, manually measured rain data, see the Local Precip Data page.
0.00 in
Rain Rate (/hr):
0.00 in
Rain Last 60 min:
0.01 in
Rain Today:
0.00 in
Monday:
0.01 in
July:
1.26 in
2026
1:17pm
36.1°F
High today:
12:00am
25.2°F
Low today:
2:28pm
30.4°F
High Monday:
7:11am
16.2°F
Low Monday:
12:00am
25.2°F
Low wind chill today:
7:11am
16.2°F
Low wind chill Monday:
1:17pm
33.3°F
High dew pt today:
11:56pm
20.7°F
High dew pt Monday:
None
Wind gust today:
None
Wind gust Monday:
No alerts/warnings active for Southeast Middlesex County.
First Light:
6:11am
Sunrise:
6:39am
Sunset:
5:19pm
Twilight ends:
5:47pm
Daylight length:
10 hours 39 minutes
Phase:
First Quarter (82%)
Moon set:
8:18am
Moon rise:
9:38pm