Lexington, Massachusetts, USA
68.4°F
20.2°C
Comfortable
Overcast
Tonight: Lo 64 °F
Tuesday: Hi 70 °F
Dew Point:
60.1°F
Humidity:
75%
Barometer:
mb
Rain Rate: 0.00 in/hr
Rain Today: 0.00 in
Rain Monday: 0.00 in
Visibility: 10 miles
Wind:
Now: Calm
Avg: Calm
Gusts: 2 mph
Issued by:
National Weather Service Boston / Norton, MA
Point Forecast Updated Mon Aug 31, 2026 2:21pm EDT
- A cool and wet start to meteorological fall. Some rain could be heavy, leading to poor drainage flooding.
- Unsettled weather late Wed into Thursday, with several rounds of showers and thunderstorms. Low confidence on exact timing.
- Improving weather Friday and into the holiday weekend. Other than a spot diurnal shower each day, dry weather prevails with a mix of clouds and sun. Cooler than normal with highs in the 70s and lows in the 50s, along with onshore breezes.
Mostly Cloudy then Slight Chance Rain Showers
Lo 64 °F
A slight chance of rain showers after 4am. Mostly cloudy, with a low around 64. South wind around 6 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
Rain Showers
Hi 70 °F
A chance of rain showers before 7am, then rain showers and patchy fog between 7am and 2pm, then patchy fog and showers and thunderstorms. Mostly cloudy, with a high near 70. Southeast wind 2 to 8 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Chance Rain Showers
Lo 61 °F
A chance of rain showers and patchy fog before 2am. Cloudy, with a low around 61. East wind 3 to 7 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
Mostly Cloudy
Hi 73 °F
Mostly cloudy, with a high near 73. East wind 3 to 7 mph.
Rain Showers
Lo 62 °F
Rain showers between 8pm and 5am, then showers and thunderstorms. Cloudy, with a low around 62. Southeast wind around 6 mph. Chance of precipitation is 90%.
Showers And T-Storms
Hi 80 °F
Showers and thunderstorms. Mostly cloudy, with a high near 80. South wind 6 to 9 mph. Chance of precipitation is 90%.
Showers And T-Storms Likely
Lo 64 °F
Showers and thunderstorms likely before 1am. Mostly cloudy, with a low around 64. West wind around 6 mph. Chance of precipitation is 70%.
Mostly Sunny
Hi 80 °F
Mostly sunny, with a high near 80. Northwest wind 5 to 8 mph.
Partly Cloudy
Lo 61 °F
Partly cloudy, with a low around 61. Northwest wind around 6 mph.
Mostly Sunny then Slight Chance Rain Showers
Hi 73 °F
A slight chance of rain showers after 5pm. Mostly sunny, with a high near 73. North wind 6 to 9 mph.
Partly Cloudy
Lo 56 °F
Partly cloudy, with a low around 56. North wind around 6 mph.
Mostly Sunny
Hi 72 °F
Mostly sunny, with a high near 72. North wind around 8 mph.
Partly Cloudy
Lo 55 °F
Partly cloudy, with a low around 55. North wind 2 to 6 mph.
Sunny
Hi 76 °F
Sunny, with a high near 76. Northeast wind around 6 mph.
Issued by:
National Weather Service Boston / Norton, MA
Updated Mon Aug 31, 2026 2:21pm EDT

SW 5 mph
SW 5 mph
SW 3 mph
SW 3 mph
SW 3 mph
S 3 mph
S 2 mph
SE 3 mph
SE 3 mph
SE 3 mph
SE 5 mph
SE 6 mph
SE 7 mph
SE 7 mph
SE 8 mph
E 8 mph
E 7 mph
E 7 mph
E 7 mph
E 6 mph
E 5 mph
E 5 mph
E 5 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 3 mph
E 5 mph
E 6 mph
E 7 mph
E 7 mph
000
FXUS61 KBOX 311801
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
201 PM EDT Mon Aug 31 2026
.WHAT HAS CHANGED...
No significant changes.
&&
.KEY MESSAGES...
- A cool and wet start to meteorological fall. Some rain could
be heavy, leading to poor drainage flooding.
- Unsettled weather late Wed into Thursday, with several rounds
of showers and thunderstorms. Low confidence on exact timing.
- Improving weather Friday and into the holiday weekend. Other
than a spot diurnal shower each day, dry weather prevails with
a mix of clouds and sun. Cooler than normal with highs in the
70s and lows in the 50s, along with onshore breezes.
&&
.DISCUSSION...
KEY MESSAGE 1...A cool and wet start to meteorological fall. Some
rain could be heavy, leading to poor drainage flooding.
The backdoor cold front that pushed southwest of New England this
morning starts to shift back to the northeast today, with increasing
cloud cover this afternoon. As advertised the past several days,
there are multiple rounds of beneficial rainfall this week, with the
first round coming late tonight through Tuesday. With the frontal
boundary shifting northeast, PWATs increase to between 1.8-2.0
inches, interacting with a weak wave of low pressure riding along
the boundary.
Timing-wise, rain aims to arrive around midnight west of the CT
River Valley and around the time of the Tuesday morning commute for
the I-95 corridor. Looking at BUFKIT, do see warm rain processes
with the warm cloud layer around 10k feet. Locally heavy downpours,
especially during the daytime Tuesday, are possible, which may lead
to localized street and poor drainage flooding. This coincides with
the Day 1-2 ERO Marginal Risk (level 1 out of 4) for excessive
rainfall.
Do think there will be a thin axis of heaviest rainfall across the
southwest section of our CWA. Rainfall amounts are in the
neighborhood of half an inch to an inch, with lesser amounts east of
I-95, where totals are in the range of a quarter to half an inch.
Since these are showers versus stratiform rain, there could be areas
of higher and lower amounts within a relatively short distance.
However, a subtle shift northeast could put some of the heaviest
rainfall across parts of central Massachusetts and eastern
Connecticut. Additionally, there's a lower chance for thunder,
mainly Tuesday afternoon, with a few hundred J/kg of CAPE across
mainly western Massachusetts and Connecticut, although it's not a
significant risk.
Rain tapers off late Tuesday, with drier conditions overspreading
the region Tuesday night into early Thursday morning. Given the
clouds, expect a much cooler start to Tuesday, with highs mainly in
the upper 60s to lower 70s. A true nod to the first day of
meteorological fall.
KEY MESSAGE 2...Unsettled weather late Wed into Thursday, with
several rounds of showers and thunderstorms. Low confidence on exact
timing.
1025 mb high pressure over the Maritimes should provide dry weather
much of Wed, especially across eastern MA, while a frontal boundary
lurks to the west and southwest of SNE. This front will eventually
move northeast as a warm front later Wed and especially Wed night,
resulting in an increased risk for showers and thunderstorms across
SNE late Wed/Wed night. Cooler temps Wed, with 1025 Maritime high
and ESE onshore flow, limiting max temps in the upper 60s and lower
70s.
Trailing/secondary short wave and associated cold front impact the
region around Thu. Potential for thunderstorms to become strong to
severe during this time, as warm sector airmass overspreads SNE.
However, better instability/higher theta-e airmass appears to remain
southwest of SNE. Thus, potential for severe weather and flash
flooding here looks limited at this time range. Heat and humidity
return Thu with warm sector airmass, highs in the lower 80s and dew
pts in the upper 60s and lower 70s.
KEY MESSAGE 3...Improving weather Friday and into the holiday
weekend. Other than a spot diurnal shower each day, dry weather
prevails with a mix of clouds and sun. Cooler than normal with highs
in the 70s and lows in the 50s, along with onshore breezes.
Definitely a sign of fall approaching, with robust northern stream
Friday yielding a baroclinic 998 mb maritime low late Fri/Sat. This
will yield a cool, brisk NE flow into the SNE over the weekend.
Highs likely remaining in the 70s and overnight lows in the 50s. It
will feel even cooler over southeast MA, including Cape Cod and the
Islands, with northeast winds 15-25 mph. Cool cyclonic flow aloft
will yield diurnal clouds each day and possibly a spot shower.
Otherwise, dry weather prevails. Possibly warmer and less wind for
Memorial Day Monday, as high amplitude trough moves offshore and
1025 mb high settles over SNE.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
18Z TAF Update:
Through 00Z...High confidence.
VFR and dry. However, mid-level clouds are increasing from west to
east a slow-moving front lifts east-northeast. Coastal sea breezes
continue today at around 10 kt, while inland winds remain southerly
at less than 6 kt.
Tonight...High confidence in trends, moderate confidence in timing.
Ceilings lower to low-end MVFR, if not IFR, as SHRA arrives from
west to east between 06Z and 12Z. Conditions eventually deteriorate
to LIFR across interior terminals by 08-10Z, with visibilities
lowering to 2-5 SM. There is a low chance of lightning, with the
greatest probability across western terminals in southern New
England, particularly KBDL. Winds shift from south to southeast
overnight, remaining light across interior southern New England and
increasing to 8-10 kt at coastal terminals.
Tuesday...Moderate confidence.
Pockets of LIFR to start; otherwise, a mixture of IFR and MVFR
ceilings persists, with periodic showers and isolated TSRA possible.
East-southeast winds of 10-15 kt are expected at coastal terminals
and 6-10 kt at interior terminals.
Tuesday Night...Moderate confidence.
MVFR ceilings generally prevail along and east of I-95, while areas
farther inland remain IFR to LIFR. Onshore easterly winds and
chances for SHRA continue.
KBOS Terminal...High confidence in trends, moderate confidence in timing.
KBDL Terminal...High confidence in trends, moderate confidence in timing.
Outlook /Tuesday Night through Saturday/...
Wednesday: Mainly VFR, with local IFR possible. Chance SHRA,
slight chance TSRA.
Wednesday Night: MVFR/IFR conditions possible. SHRA, chance
TSRA.
Thursday: Mainly VFR, with local IFR possible. Chance SHRA,
chance TSRA.
Thursday Night: Mainly VFR, with local IFR possible. Chance
SHRA.
Friday: VFR. Slight chance SHRA.
Friday Night through Saturday: VFR. Breezy. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through Tuesday Night...High confidence.
High pressure situated over the Gulf of Maine shifts northeast
toward the Canadian Maritimes tonight as a semi-stationary front
lifts northeast. A series of low pressure systems will ride along
this boundary, beginning tonight and bringing unsettled weather.
Rain develops late tonight into Tuesday, potentially leading to poor
visibility. Southerly winds overnight become east-southeast Tuesday
and easterly Tuesday night, with speeds of 10 to 15 kt and gusts
around 20 kt. Seas remain below 2 ft tonight, then slowly build to 2
to 3 ft Tuesday and possibly 3 to 5 ft by late Tuesday night or
early Wednesday morning. Building seas may warrant a Small Craft
Advisory for the outer waters, but no headlines have been issued at
this time.
Outlook /Tuesday Night through Saturday/...
Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.
Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Rain showers likely, chance of thunderstorms.
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers, chance of thunderstorms.
Thursday Night: Winds less than 25 kt. Chance of rain showers.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Friday Night: Winds less than 25 kt.
Saturday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
DISCUSSION...Dooley/Nocera
AVIATION...Dooley/Nocera
MARINE...Dooley/Nocera
Radar images courtesy Weather Underground / Intellicast.
UV Index forecast high for today: 1 Low
Current (Estimated): 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:
0.00 in
Rain Today:
0.00 in
Monday:
0.00 in
September:
19.90 in
2026
12:00am
68.5°F
High today:
12:14am
68.4°F
Low today:
12:43pm
78.1°F
High Monday:
7:20am
61.9°F
Low Monday:
12:00am
60.6°F
High dew pt today:
12:00am
65.3°F
High dew pt Monday:
12:03am
5 mph
Wind gust today:
9:05pm
7 mph
Wind gust Monday:
No alerts/warnings active for Southeast Middlesex County.
First Light:
5:42am
Sunrise:
6:10am
Sunset:
7:19pm
Twilight ends:
7:48pm
Daylight length:
13 hours 9 minutes
Phase:
Waning Gibbous (83%)
Moon set:
11:08am
Moon rise:
9:09pm