Lexington, Massachusetts, USA
66.6°F
19.2°C
Comfortable
Clear
Today: Hi 65 °F
Tonight: Lo 42 °F
Dew Point:
44.1°F
Humidity:
44%
Barometer:
mb
Rain Rate: 0.00 in/hr
Rain Today: 0.00 in
Rain Wednesday: 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 Thu May 21, 2026 6:42am EDT
- Seasonable temps with scattered showers Thursday morning, lingering longest over CT, RI and SE MA. Dry and mild weather continues Friday.
- Cooler temperatures through Memorial Day Weekend. Unsettled weather returns for the weekend, but not a washout every day. Sunday is the wettest of the three days.
Slight Chance Rain Showers then Cloudy
Hi 65 °F
A slight chance of rain showers before 11am. Cloudy, with a high near 65. North wind around 7 mph. Chance of precipitation is 20%.
Mostly Cloudy
Lo 42 °F
Mostly cloudy, with a low around 42. North wind around 5 mph.
Mostly Sunny
Hi 65 °F
Mostly sunny, with a high near 65. East wind around 7 mph.
Mostly Cloudy
Lo 48 °F
Mostly cloudy, with a low around 48. Southwest wind 1 to 7 mph.
Mostly Cloudy
Hi 64 °F
Mostly cloudy, with a high near 64. East wind 1 to 8 mph.
Rain Showers Likely
Lo 47 °F
Rain showers likely after 8pm. Cloudy, with a low around 47. East wind 3 to 7 mph. Chance of precipitation is 60%.
Rain Showers
Hi 57 °F
Rain showers. Cloudy, with a high near 57. East wind 7 to 10 mph. Chance of precipitation is 80%.
Rain Showers Likely
Lo 49 °F
Rain showers likely. Cloudy, with a low around 49. East wind 5 to 9 mph. Chance of precipitation is 70%.
Chance Rain Showers
Hi 68 °F
A chance of rain showers. Cloudy, with a high near 68. North wind around 6 mph. Chance of precipitation is 40%.
Chance Rain Showers
Lo 53 °F
A chance of rain showers before 2am. Mostly cloudy, with a low around 53. Southwest wind around 5 mph. Chance of precipitation is 30%.
Mostly Sunny
Hi 79 °F
Mostly sunny, with a high near 79. Northwest wind 2 to 7 mph.
Partly Cloudy
Lo 57 °F
Partly cloudy, with a low around 57. West wind around 7 mph.
Mostly Sunny then Slight Chance Rain Showers
Hi 79 °F
A slight chance of rain showers after 2pm. Mostly sunny, with a high near 79. Northwest wind 5 to 9 mph.
Slight Chance Rain Showers then Partly Cloudy
Lo 55 °F
A slight chance of rain showers before 8pm. Partly cloudy, with a low around 55. Northwest wind 3 to 7 mph.
Issued by:
National Weather Service Boston / Norton, MA
Updated Thu May 21, 2026 6:42am EDT

NW 5 mph
NW 5 mph
N 5 mph
N 5 mph
N 3 mph
N 3 mph
NE 3 mph
NE 3 mph
N 3 mph
N 3 mph
N 3 mph
N 5 mph
N 5 mph
N 5 mph
N 5 mph
N 5 mph
N 5 mph
NE 5 mph
NE 6 mph
NE 6 mph
NE 6 mph
NE 7 mph
E 7 mph
E 7 mph
E 7 mph
E 7 mph
E 7 mph
SE 7 mph
SE 7 mph
SE 6 mph
SE 5 mph
SE 3 mph
S 3 mph
S 3 mph
S 2 mph
SW 2 mph
000
FXUS61 KBOX 211659
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
1259 PM EDT Thu May 21 2026
.WHAT HAS CHANGED...
Sunday looking like the wettest day of the holiday weekend with
drier days on either side.
&&
.KEY MESSAGES...
- Seasonable temps with scattered showers Thursday morning,
lingering longest over CT, RI and SE MA. Dry and mild weather
continues Friday.
- Cooler temperatures through Memorial Day Weekend. Unsettled
weather returns for the weekend, but not a washout every day.
Sunday is the wettest of the three days.
&&
.DISCUSSION...
KEY MESSAGE 1...Seasonable temps with scattered showers Thursday
morning, lingering longest over CT, RI and SE MA. Dry and mild
weather continues Friday.
As the low pressure moves off into the North Atlantic, Thursday will
be a transition between two starkly different airmasses. The post
frontal airmass has arrived with cooler NW flow in place across SNE.
High pressure over the Great Lakes will be slow to advance eastward
over the next 24 hours as will the drier air it brings with it. We
remain on the northern periphery of deeper moisture to our south.
With zonal flow in the mid levels and a weak shortwave this morning
we'll see a resurgence of light showers, lingering longest over CT,
RI, and southeast MA through noon. By afternoon drier air sinks
further south and skies will clear making way for a good radiational
cooling night under high pressure so have leaned on MOS guidance for
low temps. Expect plenty of sun Friday under strong subsidence, with
highs in the upper 60s to low 70s (normal for late May).
KEY MESSAGE 2...Cooler temperatures through Memorial Day Weekend.
Unsettled weather returns for the weekend, but not a washout every
day. Sunday is the wettest of the three days.
Guidance is slowly coming into better agreement on the weather for
the upcoming holiday weekend. While we continue to forecast a cooler
than normal weekend with wet weather, the full three day weekend
shouldn't be a washout. As it stands now, surface high pressure will
be fighting to keep low pressure from the OH valley and its
associated wet weather at bay as long as possible; this means the
earlier in the day on Saturday the better chance we stay dry, it
could even hold out for a fully dry Saturday, especially toward
northeast/north central MA. Eventually the shortwave and wet weather
move over SNE Saturday night/Sunday and this looks to be the most
likely "washout" day before the low moves east of MA by Monday with
drier air funneling in and making for a more pleasant day than
Sunday. Sunday will also be breezy as a 25-35kt LLJ moves overhead.
Temperatures bottom out on Sunday with highs in the upper 50s,
warming into the upper 60s and 70s by Monday.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
18z TAF Update...
Through Tonight...High confidence.
VFR. Few lingering rain showers along the immediate coast come to an
end this evening, but not expecting any operational impacts. N wind
5-10 kt with sea-breezes. Winds becoming light/variable or calm
overnight.
Friday...High confidence.
VFR. NE winds 5-10 kt.
Friday Night...High confidence.
VFR. Increasing mid and high-level clouds NE winds less than 5 kt.
KBOS...High confidence in TAF.
KBDL...High confidence in TAF.
Outlook /Friday Night through Tuesday/...
Friday Night: VFR.
Saturday: VFR. Chance SHRA.
Saturday Night through Sunday: VFR. Breezy. SHRA likely.
Sunday Night: VFR. Chance SHRA.
Memorial Day: Mainly VFR, with local MVFR possible. Chance
SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Winds NW 10-15 kts with sea-breezes developing over nearshore
waters in the afternoon. Light winds Thu night becoming N-NE
overnight into Friday.
Outlook /Friday Night through Tuesday/...
Friday Night: Winds less than 25 kt.
Saturday: Winds less than 25 kt. Chance of rain showers.
Saturday Night through Sunday: Low risk for Small Craft
Advisory winds with gusts up to 25 kt. Local rough seas. Rain
showers likely.
Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Rain
showers likely.
Memorial Day: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
DISCUSSION...BW
AVIATION...Dooley
MARINE...BW
Radar images courtesy Weather Underground / Intellicast.
UV Index forecast high for today: 5 Medium
Current (Estimated): 5 Medium
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
Wednesday:
1.24 in
May:
8.74 in
2026
51.1 in
Season Snow:
12:00am
72.0°F
High today:
8:27am
60.4°F
Low today:
1:16pm
88.0°F
High Wednesday:
6:03am
69.6°F
Low Wednesday:
1:32am
53.8°F
High dew pt today:
10:07am
70.9°F
High dew pt Wednesday:
1:15pm
93.0°F
High heat index Wednesday:
5:07am
4 mph
Wind gust today:
3:09pm
12 mph
Wind gust Wednesday:
No alerts/warnings active for Southeast Middlesex County.
First Light:
4:44am
Sunrise:
5:17am
Sunset:
8:06pm
Twilight ends:
8:39pm
Daylight length:
14 hours 48 minutes
Phase:
Waxing Crescent (31%)
Moon set:
12:34am
Moon rise:
10:05am