Lexington, Massachusetts, USA
82.8°F
28.2°C
Feels like 82.9°F
Hot
Clear
This Afternoon: Hi 85 °F
Tonight: Lo 62 °F
Dew Point:
59.9°F
Humidity:
46%
Barometer:
mb
Rain Rate: 0.00 in/hr
Rain Today: 0.00 in
Rain Monday: 1.46 in
Visibility: 10 miles
Wind:
Now: Calm
Avg: Calm
Gusts: 4 mph
Issued by:
National Weather Service Boston / Norton, MA
Point Forecast Updated Tue Aug 4, 2026 12:43pm EDT
- Weak low pressure brings some clouds and a low risk for a shower early Wednesday across Martha's Vineyard and Nantucket
- Increasing heat and humidity across much of southern New England, along with daily afternoon pop-up thunderstorms from Thursday through this weekend. A widespread washout is not anticipated at this time.
Sunny
Hi 85 °F
Sunny, with a high near 85. Southwest wind around 6 mph.
Partly Cloudy
Lo 62 °F
Partly cloudy, with a low around 62. Southwest wind around 5 mph.
Partly Sunny
Hi 87 °F
Partly sunny, with a high near 87. Southwest wind 2 to 6 mph.
Partly Cloudy
Lo 68 °F
Partly cloudy, with a low around 68. Southwest wind around 6 mph.
Mostly Sunny then Slight Chance Showers And T-Storms
Hi 90 °F
A slight chance of showers and thunderstorms between 2pm and 4pm, then a chance of showers and thunderstorms between 4pm and 5pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 90. Southwest wind 3 to 7 mph. Chance of precipitation is 30%.
Chance Showers And T-Storms then Partly Cloudy
Lo 72 °F
A chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 72. Southwest wind around 6 mph. Chance of precipitation is 30%.
Sunny then Slight Chance Showers And T-Storms
Hi 91 °F
A slight chance of showers and thunderstorms between 2pm and 4pm, then a chance of showers and thunderstorms. Sunny, with a high near 91. West wind around 7 mph. Chance of precipitation is 30%.
Chance Showers And T-Storms
Lo 71 °F
A chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 71. Southwest wind around 5 mph. Chance of precipitation is 30%.
Mostly Sunny then Chance Showers And T-Storms
Hi 89 °F
A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 89. Southwest wind 3 to 8 mph. Chance of precipitation is 40%.
Chance Showers And T-Storms then Partly Cloudy
Lo 70 °F
A chance of showers and thunderstorms before 9pm. Partly cloudy, with a low around 70. West wind around 7 mph. Chance of precipitation is 40%.
Sunny
Hi 89 °F
Sunny, with a high near 89. West wind 5 to 9 mph.
Mostly Clear
Lo 69 °F
Mostly clear, with a low around 69. West wind 5 to 8 mph.
Sunny then Slight Chance Rain Showers
Hi 89 °F
A slight chance of rain showers after 4pm. Sunny, with a high near 89. West wind 5 to 10 mph, with gusts as high as 21 mph.
Slight Chance Rain Showers
Lo 68 °F
A slight chance of rain showers. Partly cloudy, with a low around 68. West wind 5 to 9 mph.
Issued by:
National Weather Service Boston / Norton, MA
Updated Tue Aug 4, 2026 12:43pm EDT

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000
FXUS61 KBOX 041859
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
259 PM EDT Tue Aug 4 2026
.WHAT HAS CHANGED...
Confidence continues to increase for the region to see a stretch
of warm and humid conditions for late week into the weekend.
&&
.KEY MESSAGES...
- Weak low pressure brings some clouds and a low risk for a
shower early Wednesday across Martha's Vineyard and Nantucket
- Increasing heat and humidity across much of southern New
England, along with daily afternoon pop-up thunderstorms from
Thursday through this weekend. A widespread washout is not
anticipated at this time.
&&
.DISCUSSION...
KEY MESSAGE 1...Weak low pressure brings some clouds and a low
risk for a shower early Wednesday across Martha's Vineyard and
Nantucket
Overall a pretty quiet night, weather-wise, is expected for most
of the region. Weak high pressure over CT and western MA will
result in mostly clear skies with some patchy valley fog perhaps
forming. Low temperatures will be seasonable, generally the
lower 60s. The only other feature on the weather map is a very
weak low pressure several hundred miles of southern New England.
This will track northeast, and although it will pass south of
Nantucket late tonite/early Wednesday morning, moisture around
the low may be enough to produce a period of low clouds as far
north as Cape Cod. Low (less than 25%) chance of a light shower
is also possible across Martha's Vineyard and Nantucket between
roughly 4a-8a.
KEY MESSAGE 2...Increasing heat and humidity across much of southern
New England, along with daily afternoon pop-up thunderstorms
from Thursday through this weekend. A widespread washout is not
anticipated at this time.
There is increasing confidence in a prolonged period of midsummer
warmth and humidity, along with daily chances for afternoon pop-up
thunderstorms from Thursday through the upcoming weekend. However, a
widespread washout is not anticipated. Given the abundant rainfall
earlier this week, any storms capable of producing heavy downpours
could lead to localized instances of flash flooding. This is
reflected in the WPC Marginal Risk (Level 1 of 4) for excessive
rainfall across western New England on Thursday and all of southern
New England on Friday.
Bermuda high pressure develops this week and remains anchored over
the western Atlantic through the remainder of the forecast period.
With persistent southwesterly flow, expect above-normal temperatures
along with increasing humidity. While temperatures will be above
climatological normals, they are not particularly unusual for early
August. High temperatures from Thursday through Sunday should climb
well into the upper 80s and lower 90s, while dewpoints rise into the
lower to middle 70s. This combination will result in heat index
values of 95 to 100 degrees. If current trends continue, Heat
Advisories may be needed for portions of the region Thursday and
Friday, and perhaps Saturday as well. One uncertainty is the degree
of afternoon cloud cover and thunderstorm development, which could
temper temperatures somewhat. This will be monitored over the coming
days.
Regarding thunderstorm chances, the overall synoptic pattern
features the Bermuda High over the western Atlantic with a mid-level
ridge extending across the Northeast. Embedded shortwave
disturbances riding through the flow should provide enough lift to
initiate scattered afternoon and evening thunderstorms from Thursday
through Sunday. Although deep-layer shear remains weak, instability
will be plentiful, with forecast CAPE values generally between 1,500
and 2,000 J/kg. As a result, storms should remain largely pulse-type
and disorganized rather than organized severe convection. BUFKIT
soundings depict tall, skinny CAPE profiles, suggesting efficient
warm-rain processes and the potential for locally heavy rainfall.
PWAT values around 1.7 inches further support the threat of
torrential downpours. In addition to localized flooding, gusty winds
and frequent lightning will be the primary hazards.
That said, not every community will experience thunderstorms each
day. Many locations will remain dry, so there is no reason to cancel
outdoor plans at this point. The details regarding storm coverage
and placement will become clearer once the convection-allowing
guidance comes into range over the next couple of days.
&&
.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:
High Confidence.
Currently VFR area wide with light west winds to about 10kt.
There is a weak sea breeze along the coast south of Boston. That
sea breeze will fade prior to sunset. Weak high pressure
overhead tonight will result in generally clear skies and light
winds for most of the region. Could see some patchy valley fog,
but not expecting any at TAF locations. Slightly different
outlook for the Cape and Islands. Weak low pressure will pass
south of ACK late tonight, but could be close enough to result
in some lower ceilings. Have some MVFR for FMH and HYA, and IFR
at ACK. Could even see -SHRA at ACK early in the morning. Any
low ceilings should clear out by 14z.
Otherwise Wednesday will feature VFR. Believe a sea breeze will
again form. Although an isolated shower can't be ruled out
across the western interior. Increasing moisture Wednesday night
should result in MVFR/IFR conditions as low clouds, especially
across the southern coastal areas. May also see a few -SHRA
develop prior to 12z Thursday across CT.
KBOS Terminal...High confidence in TAF. Sea breeze today is
expected to stay just east of the airport, but could make a
quick visit prior to 22z.
KBDL Terminal...High confidence in TAF. Winds may be a bit
variable this afternoon before settling into a more southerly
wind direction.
Outlook /Thursday through Sunday/...
Thursday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, chance TSRA.
Thursday Night: VFR.
Friday: VFR. Breezy. Chance SHRA, slight chance TSRA.
Friday Night: VFR. Slight chance SHRA, slight chance TSRA.
Saturday: VFR. Breezy. Chance SHRA, chance TSRA.
Saturday Night through Sunday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
The need for a Small Craft Advisory across the outer southern
waters will come to an end by early this evening as seas slowly
subside to below 5ft. Otherwise a "Bermuda High" will become
firmly entrenched off the eastern sea board resulting in an
extended period of SW winds.
Outlook /Thursday through Sunday/...
Thursday: Winds less than 25 kt.
Thursday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Friday: Winds less than 25 kt.
Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.
Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Saturday Night: Winds less than 25 kt. Slight chance of rain
showers.
Sunday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents until 9 PM EDT this evening for MAZ020-
023-024.
RI...High Risk for Rip Currents until 9 PM EDT this evening for
RIZ006>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ255-
256.
&&
$$
DISCUSSION...Dooley/Nash
AVIATION...Dooley/Nash
MARINE...Dooley/Nash
Radar images courtesy Weather Underground / Intellicast.
UV Index forecast high for today: 8 Very High
Current (Estimated): 6 High
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:
1.46 in
Monday:
1.46 in
August:
19.12 in
2026
2:45pm
83.5°F
High today:
5:54am
63.0°F
Low today:
7:56am
77.4°F
High Monday:
11:58pm
67.6°F
Low Monday:
11:20am
67.3°F
High dew pt today:
7:56am
74.5°F
High dew pt Monday:
2:54pm
85.1°F
High heat index today:
3:20pm
10 mph
Wind gust today:
6:28am
18 mph
Wind gust Monday:
No alerts/warnings active for Southeast Middlesex County.
First Light:
5:09am
Sunrise:
5:41am
Sunset:
8:01pm
Twilight ends:
8:33pm
Daylight length:
14 hours 21 minutes
Phase:
Waning Gibbous (64%)
Moon set:
12:04pm
Moon rise:
10:36pm