Lexington, Massachusetts, USA
69.6°F
20.9°C
Muggy
Mostly cloudy
Overnight: Lo 66 °F
Tuesday: Hi 80 °F
Dew Point: 67.5°F
Humidity: 93%
Barometer:
mb
Rain Rate: 0.00 in/hr
Rain Today: 0.00 in
Rain Monday: 0.17 in
Visibility: 10 miles
Wind:
Now: Calm
Avg: Calm
Gusts: 0 mph
Issued by:
National Weather Service Boston / Norton, MA
Point Forecast Updated Tue Aug 18, 2026 2:28am EDT
- Gradual clearing today with a low chance of showers in parts of the interior. Drier into Wednesday.
- Generally becoming unsettled once again towards the second half of the week into the start of next week.
Patchy Fog
Lo 66 °F
Patchy fog. Mostly cloudy, with a low around 66. North wind around 2 mph.
Patchy Fog then Slight Chance Rain Showers
Hi 80 °F
Patchy fog before 9am, then a slight chance of rain showers. Partly sunny, with a high near 80. Northeast wind around 5 mph. Chance of precipitation is 20%.
Slight Chance Rain Showers then Mostly Cloudy
Lo 65 °F
A slight chance of rain showers before 8pm. Mostly cloudy, with a low around 65. South wind 1 to 5 mph. Chance of precipitation is 20%.
Mostly Sunny
Hi 86 °F
Mostly sunny, with a high near 86. Southwest wind 2 to 8 mph.
Partly Cloudy
Lo 67 °F
Partly cloudy, with a low around 67. West wind around 6 mph.
Mostly Sunny then Chance Rain Showers
Hi 83 °F
A chance of rain showers after 2pm. Mostly sunny, with a high near 83. Northwest wind around 6 mph. Chance of precipitation is 30%.
Chance Rain Showers then Partly Cloudy
Lo 62 °F
A chance of rain showers before 8pm. Partly cloudy, with a low around 62. Northwest wind around 5 mph. Chance of precipitation is 30%.
Mostly Sunny
Hi 82 °F
Mostly sunny, with a high near 82. Northeast wind 3 to 7 mph.
Partly Cloudy then Slight Chance Rain Showers
Lo 62 °F
A slight chance of rain showers after 4am. Partly cloudy, with a low around 62. East wind 1 to 6 mph.
Chance Rain Showers
Hi 79 °F
A chance of rain showers. Partly sunny, with a high near 79. Northeast wind 2 to 8 mph. Chance of precipitation is 40%.
Rain Showers Likely
Lo 62 °F
Rain showers likely. Mostly cloudy, with a low around 62. Northeast wind 2 to 6 mph. Chance of precipitation is 60%.
Rain Showers Likely
Hi 79 °F
Rain showers likely before 2pm, then showers and thunderstorms likely. Mostly cloudy, with a high near 79. Northeast wind 3 to 7 mph. Chance of precipitation is 60%.
Chance Showers And T-Storms
Lo 61 °F
A chance of showers and thunderstorms. Mostly cloudy, with a low around 61. South wind around 6 mph. Chance of precipitation is 50%.
Chance Rain Showers then Slight Chance Showers And T-Storms
Hi 80 °F
A chance of rain showers before 2pm, then a slight chance of showers and thunderstorms. Partly sunny, with a high near 80. West wind 5 to 9 mph.
Issued by:
National Weather Service Boston / Norton, MA
Updated Tue Aug 18, 2026 6:13am EDT

N 2 mph
N 3 mph
N 3 mph
N 3 mph
NE 3 mph
N 3 mph
N 5 mph
NE 5 mph
E 3 mph
E 5 mph
E 5 mph
E 5 mph
SE 5 mph
SE 5 mph
SE 3 mph
SE 3 mph
S 2 mph
S 2 mph
S 2 mph
S 2 mph
S 1 mph
S 2 mph
SW 2 mph
SW 2 mph
W 2 mph
W 3 mph
SW 3 mph
SW 2 mph
SW 3 mph
SW 6 mph
SW 6 mph
SW 7 mph
SW 8 mph
W 8 mph
W 7 mph
SW 7 mph
000
FXUS61 KBOX 180800
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
400 AM EDT Tue Aug 18 2026
.WHAT HAS CHANGED...
No significant changes.
&&
.KEY MESSAGES...
- Gradual clearing today with a low chance of showers in parts of
the interior. Drier into Wednesday.
- Generally becoming unsettled once again towards the second
half of the week into the start of next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Gradual clearing today with a low chance of
showers in parts of the interior. Drier into Wednesday.
Low pressure continues to pull off to the east and northeast today,
which will allow for slow clearing, developing from west to
east. Onshore flow persists as this low pulls further away from
the region, which will likely keep temperatures near the coasts
slightly cooler in the 70s. The rest of southern New England
may reach the low 80s, as that's where clouds should scatter
out sooner. With the clearer conditions inland, it will also be
less humid as winds shift more northwest. A spot shower or two
cannot be entirely ruled out across much of central MA into RI,
CT this afternoon. Tonight should be calm with patchy fog
possible and lows in the 60s.
Zonal flow persists aloft into Wednesday as an upper level low
tracks well to our north across the Hudson Bay. Some guidance does
indicate some shortwave energy moving within the flow across the
region later Wed into Thu which could lead to a spot shower or two,
however the more favorable parameters remain to our north and west.
KEY MESSAGE 2...Generally becoming unsettled once again towards
the second half of the week into the start of next week.
A stronger shortwave within the flow aloft makes its way east
heading into Thursday, bringing with it more favorable dynamics and
moisture for showers. Discrepancies still remain regarding the
wave's track across the ensemble and deterministic guidance, with
the GEFS continuing to show higher probabilities for 24 hour
rainfall of 0.1"+ extending into CT, SE MA, and RI while the ECMWF
and Canadian ensembles continue to favor a more southern track.
NAEFS guidance, notably, keeps the more anomalous moisture off to
our south and east, though PWAT values reaching to around 1.5" are
not out of the question.
Under the post-frontal airmass Friday with high pressure overhead,
conditions will be drier overall. Temperatures will likely be in the
low 80s and down to the mid 70s, particularly along the coasts where
onshore winds will keep it slightly cooler. Conditions become
unsettled once more, though, as we keep an eye on a deepening trough
digging into the Great Lakes region towards the weekend period.
Shortwaves moving along the boundary that may stall just off the
east coast could bring chances for showers. Thunderstorms could be a
possibility depending on if these waves could take advantage of
daytime heat. More details will become apparent as we approach this
timeframe.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through 12z...Moderate confidence
Pockets of IFR are continuing to develop across the region,
with some areas reaching LIFR. Notably, coastal terminals have
hit this sooner. Light E to NE winds continue over more coastal
terminals with calm conditions persisting over the interior
terminals.
Tuesday...Moderate confidence (ceilings)
MVFR to IFR conditions to start, with improvement to VFR from west
to east between 17Z and 20Z. Improvements for terminals further
east may be slower and may only top out to MVFR based on
guidance, though VFR by 00z is a possibility for Cape/Islands
terminals. Light N winds become more NW during the afternoon for
the interior terminals, while onshore NE/E winds continues for
eastern terminals, generally at 5-10 kt. Higher winds above 10
kt are possible for ACK.
Tuesday Night...Moderate confidence.
VFR across the interior, though MVFR towards the Cape/Islands,
along with RI terminals, depending on how thick cloud cover
remains. Otherwise, SCT to FEW at lower ceilings. ACK could see
return of IFR conditions. Light NW to SW winds less than 10 kt
with patchy fog possible.
Wednesday...High confidence.
VFR. WSW winds over much of the region, more SSW over the
coastal areas all at 5-10 kt.
KBOS Terminal...Moderate confidence.
LIFR visby possible periodically early this morning through at
least 08z. Exact timing of improvements to VFR lower
confidence, but more likely between 16-19Z. SCT MVFR decks
possible through the afternoon. Winds NE becoming E in the
afternoon 7-10 kts.
KBDL Terminal...Moderate confidence.
MVFR conditions have just moved in to the terminal and are
expected to continue through the rest of tonight into the
mornings hours. Periods of IFR cannot be entirely ruled out for
the early morning hours. Chance of fog remains.
Outlook /Wednesday Night through Saturday/...
Wednesday Night: VFR.
Thursday: VFR. Slight chance SHRA, slight chance TSRA.
Thursday Night through Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. Chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through Wednesday Night...Moderate confidence.
Low pressure continues to shift farther off to the east. Seas
diminish more to 2-4 ft across the coastal and nearshore waters.
Ocean waters off to the east may take longer to drop off as they
may get to around 5-6 ft heading into tonight. By Wednesday,
seas fall to 2-3 ft across all waters. Winds through this period
remain generally under 15 kt outside of occasional gusts in the
afternoons. More N winds shift W, then S tonight, then more SW
by Wednesday night.
A higher rip current risk is expected for east-facing
beaches where a Rip Current Statement is in effect from 8 AM
this morning through 8 PM tonight.
Outlook /Wednesday Night through Saturday/...
Wednesday Night: Winds less than 25 kt.
Thursday: Winds less than 25 kt. Slight chance of rain showers.
Thursday Night: Winds less than 25 kt. Chance of rain showers,
slight chance of thunderstorms.
Friday through Saturday: Winds less than 25 kt. Chance of rain
showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents from 8 AM EDT this morning through this
evening for MAZ007-015-016-019-022-024.
RI...None.
MARINE...None.
&&
$$
DISCUSSION...Hrencecin
AVIATION...Hrencecin
MARINE...Hrencecin
Radar images courtesy Weather Underground / Intellicast.
UV Index forecast high for today: 4 Medium
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:
0.17 in
Monday:
1.63 in
August:
19.29 in
2026
12:01am
71.1°F
High today:
6:12am
69.4°F
Low today:
2:30pm
73.9°F
High Monday:
8:37am
65.5°F
Low Monday:
12:03am
68.0°F
High dew pt today:
4:00pm
68.7°F
High dew pt Monday:
12:36am
1 mph
Wind gust today:
7:24am
16 mph
Wind gust Monday:
No alerts/warnings active for Southeast Middlesex County.
First Light:
5:26am
Sunrise:
5:55am
Sunset:
7:42pm
Twilight ends:
8:12pm
Daylight length:
13 hours 47 minutes
Phase:
Waxing Crescent (34%)
Moon rise:
12:36pm
Moon set:
10:14pm