Waltham, Massachusetts 7 Day Weather Forecast
Wx Forecast - Wx Discussion - Wx Aviation
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NWS Forecast for Waltham MA
National Weather Service Forecast for:
Waltham MA
Issued by: National Weather Service Norton, MA |
Updated: 6:15 am EDT Jul 9, 2025 |
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Today
 Showers Likely and Patchy Fog then Slight Chance T-storms
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Tonight
 Chance Showers and Patchy Fog
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Thursday
 Showers Likely and Patchy Fog
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Thursday Night
 Chance T-storms and Patchy Fog then Chance Showers
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Friday
 Slight Chance T-storms then Partly Sunny
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Friday Night
 Mostly Cloudy
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Saturday
 Partly Sunny
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Saturday Night
 Mostly Cloudy
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Sunday
 Partly Sunny
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Hi 76 °F |
Lo 66 °F |
Hi 73 °F |
Lo 65 °F |
Hi 80 °F |
Lo 66 °F |
Hi 83 °F |
Lo 67 °F |
Hi 87 °F |
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Today
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Showers and thunderstorms likely before 11am, then a slight chance of showers and thunderstorms after noon. Patchy fog before noon. Otherwise, cloudy, with a high near 76. Northeast wind 3 to 6 mph. Chance of precipitation is 70%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms. |
Tonight
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A chance of showers and thunderstorms. Patchy fog. Otherwise, cloudy, with a low around 66. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms. |
Thursday
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Showers likely, with thunderstorms also possible after 11am. Patchy fog. Otherwise, cloudy, with a high near 73. East wind 3 to 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms. |
Thursday Night
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A chance of showers and thunderstorms. Patchy fog before 9pm. Otherwise, cloudy, with a low around 65. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms. |
Friday
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A slight chance of showers and thunderstorms before 11am. Mostly cloudy, with a high near 80. Calm wind becoming east around 5 mph in the afternoon. Chance of precipitation is 20%. |
Friday Night
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Mostly cloudy, with a low around 66. East wind around 5 mph becoming calm in the evening. |
Saturday
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Partly sunny, with a high near 83. Calm wind becoming east around 6 mph in the afternoon. |
Saturday Night
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Mostly cloudy, with a low around 67. Southeast wind around 5 mph becoming calm in the evening. |
Sunday
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Partly sunny, with a high near 87. Calm wind becoming south 5 to 7 mph in the morning. |
Sunday Night
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Mostly cloudy, with a low around 69. Southwest wind 3 to 6 mph. |
Monday
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Partly sunny, with a high near 87. Southwest wind 3 to 7 mph. |
Monday Night
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Mostly cloudy, with a low around 70. South wind 3 to 5 mph. |
Tuesday
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Mostly sunny, with a high near 89. Light and variable wind becoming south around 6 mph in the morning. |
Forecast from NOAA-NWS
for Waltham MA.
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Weather Forecast Discussion
370
FXUS61 KBOX 090838
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
438 AM EDT Wed Jul 9 2025
.SYNOPSIS...
Slightly less hot across southern New England today, those in far
northeast Massachusetts will have the most relief, while the lower
Connecticut River Valley remains seasonably warm. Temperatures will
continue to trend cooler on Thursday, before rebounding Friday
through the upcoming weekend. As we enter a summery pattern, a daily
chance for showers and storms remain a possibility today through
Friday, with signs of drier conditions for the upcoming weekend,
then followed by more unsettled conditions early next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update: 435AM
Key Messages:
* Cooler across eastern and northeastern Massachusetts, though still
seasonably warm across interior southern New England.
* A few isolated thunderstorms are possible this afternoon.
Severe weather threat has ended, a few early morning showers linger
across far eastern Massachusetts through sunrise. In addition, there
are a couple spot showers pushing through western/central MA and are
moving eastward. These are capable of brief heavy rain and rumbles
of thunder/flashes of lightning. Northeast flow leading to stubborn
low stratus and areas of fog, this will continue into the day ahead
across eastern Massachusetts and Rhode Island.
This afternoon it`s noticeably cooler across northeast Massachusetts,
where highs struggle to hit the middle and upper 70s, this including
Boston. Moving inland and westward, away influence of the North
Atlantic Ocean, highs are seasonable reaching the lower 80s, while
the Connecticut River Valley stands the greatest chance of reaching
the upper 80s. Have opportunities for storms today, though not to the
extent experienced overnight. Forcing isn`t great, weak surface low
and a mid-level shortwave might be enough to pop isolated
thunderstorms. In addition, PWATs are still elevated, 1.8" to 2.0",
thus any storms could put down torrential downpours. Do have a
marginal risk of excessive rain, per WPC.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Tonight: Unsettled conditions remain overnight, scattered showers
and thunder. Mainly cloudy skies will lead to a mild night with lows
in the middle to upper 60s, while urban areas hold steady around 70F.
Thursday: A quasi-stationary front settles over southern New England
and will be a source for showers and storms during the day. Timing
is early to mid-afternoon through the early evening hours, though
there is lower confidence in exact location of these storms given
the convective nature. SPC does have a Marginal Risk for severe
storms, but it was mentioned in their discussion, if confidence were
to increase in the areal coverage, part of the northeast could be
upgraded to a slight risk. Area at the greatest risk are western
areas of MA & CT, where daytime heating will be more robust, getting
into the low 80s, while eastern areas are in the low to middle 70s
due to the easterly flow off the cooler ocean. Also, there is still
a low risk for excessive rainfall per the WPC ERO, which kept the
region under a marginal risk ~ PWATs are roughly 1.5" to 2.0" thus
any storms could put down torrential downpours.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Not much change to the overall synoptic pattern into Friday. Still a
risk for some showers and thunderstorms Friday. It`s likely Saturday
is the day which features the lowest chance for showers. Even Sunday
should be dry most of the time, with the risk for some showers and
thunderstorms late in the day. Have low confidence in the forecast
details early next week. Too much uncertainty with the timing of
potential showers and thunderstorms.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06Z update...Overall Moderate Confidence.
Through 12z...Moderate confidence.
Ongoing TSRA is expected to wind down across eastern MA and RI
between 06z-08z, few areas of -SHRA could linger towards 12z.
IFR ceilings spread from east to west as well, though do not
think these ceilings go any further west than KORH. Wind shifts
to the ENE 5 to 10 knots.
Today...Moderate confidence.
IFR cigs continue through most of the day from ORH east,
MVFR/VFR west of ORH. NE winds 5-10 kts. Iso TSRA this afternoon
across interior southern New England between 18z-00z.
Tonight...Moderate confidence.
MVFR to IFR conditions, slight chance for -SHRA. Light NE winds.
Thursday...Moderate confidence.
MVFR to IFR conditions. Hit and miss -SHRA and TSRA. E to ENE
wind 5 to 10 knots.
KBOS Terminal...Moderate confidence in TAF.
Moderate confidence in LIFR conditions.
KBDL Terminal...Moderate confidence in TAF.
Outlook /Thursday Night through Sunday/...
Thursday Night: MVFR/IFR conditions possible. Chance SHRA,
slight chance TSRA.
Friday: Mainly VFR, with local IFR possible. Slight chance
SHRA, slight chance TSRA.
Friday Night: Mainly VFR, with local IFR possible.
Saturday through Saturday Night: Mainly VFR, with local MVFR
possible.
Sunday: VFR. Slight chance SHRA, slight chance TSRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Today and Tonight: Moderate confidence.
Winds 5-10 kts out of the SW on the southern waters and out of the
NE on the eastern waters. Seas 2-4 ft.
Thursday: Moderate confidence.
Winds 10-15 kts out of the SSE on the southern waters and out of
the E to ESE on the eastern waters. Seas 2-4 ft.
Outlook /Thursday Night through Sunday/...
Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers, slight chance of
thunderstorms.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
Friday Night through Sunday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
ANZ254>256.
&&
$$
SYNOPSIS...Belk/Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...Belk
AVIATION...Dooley
MARINE...Dooley
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