Monthly outlook for Merrimac, MA: average high 79.6°, average low 60.8°. That is 0.2° below the climate normal for August. Precipitation is expected on 7 days (about 2.0 inches), against a normal of 5 days and 1.9 inches. The warmest day looks like 9 August (93.8°), the coolest 16 August (52°).
79.6°/60.8°
Average high / low
−0.2°
Below normal
7 / 5
Wet days / normal
2.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
82.5°
80.7°
+1°
18 August – 27 August
74.8°
78.8°
-2.2°
28 August – 6 September
at normal
77°
—
August records over 66 years
101.7°2 August 1975All-time high
46°31 August 1965All-time low
Climate normals and records are computed from the nearest reference point — Lawrence (12 mi).
Sun, 0994° / 71°0
94 °
Merrimac, Sunday, 9 August
Clear. High 94°, low 71°.
Pressure29.85 inHg
Wind11 mph W
Humidity39%
Visibility6.2 mi
Dew point62°
Mon, 1091° / 68°0
91 °
Merrimac, Monday, 10 August
Overcast. High 91°, low 68°.
Pressure29.94 inHg
Wind6.8 mph S
Humidity34%
Visibility6.2 mi
Dew point57°
Tue, 1188° / 67°0
88 °
Merrimac, Tuesday, 11 August
Partly cloudy. High 88°, low 67°.
Pressure29.77 inHg
Wind13.2 mph NW
Humidity37%
Visibility6.2 mi
Dew point56°
Wed, 1268° / 60°0.07
68 °
Merrimac, Wednesday, 12 August
Light rain. High 68°, low 60°.
Pressure29.80 inHg
Wind3.4 mph NE
Humidity97%
Visibility6.2 mi
Dew point62°
Thu, 1383° / 59°0.05
83 °
Merrimac, Thursday, 13 August
Light rain. High 83°, low 59°.
Pressure29.71 inHg
Wind11.7 mph NW
Humidity74%
Visibility—
Dew point64°
Fri, 1477° / 53°0
77 °
Merrimac, Friday, 14 August
Clear. High 77°, low 53°.
Pressure29.88 inHg
Wind12.5 mph NW
Humidity42%
Visibility—
Dew point44°
Sat, 1577° / 53°0
77 °
Merrimac, Saturday, 15 August
Clear. High 77°, low 53°.
Pressure30.09 inHg
Wind8.7 mph NW
Humidity39%
Visibility—
Dew point43°
Sun, 1679° / 52°0
79 °
Merrimac, Sunday, 16 August
Mostly clear. High 79°, low 52°.
Pressure30.27 inHg
Wind7.6 mph S
Humidity33%
Visibility—
Dew point41°
Mon, 1783° / 57°0
83 °
Merrimac, Monday, 17 August
Overcast. High 83°, low 57°.
Pressure30.18 inHg
Wind8.6 mph SW
Humidity33%
Visibility—
Dew point44°
Tue, 1872° / 63°0.3
72 °
Merrimac, Tuesday, 18 August
Rain. High 72°, low 63°.
Pressure30.03 inHg
Wind8.7 mph SW
Humidity99%
Visibility—
Dew point64°
Wed, 1976° / 62°0.11
76 °
Merrimac, Wednesday, 19 August
Light rain. High 76°, low 62°.
Pressure29.85 inHg
Wind5.5 mph NE
Humidity61%
Visibility—
Dew point60°
Thu, 2075° / 59°0
75 °
Merrimac, Thursday, 20 August
Overcast. High 75°, low 59°.
Pressure30.00 inHg
Wind6.9 mph SE
Humidity63%
Visibility—
Dew point56°
Fri, 2179° / 59°0.53
79 °
Merrimac, Friday, 21 August
Rain. High 79°, low 59°.
Pressure30.00 inHg
Wind10.6 mph S
Humidity51%
Visibility—
Dew point55°
Sat, 2276° / 62°0.79
76 °
Merrimac, Saturday, 22 August
Rain. High 76°, low 62°.
Pressure29.77 inHg
Wind8.5 mph S
Humidity92%
Visibility—
Dew point67°
Sun, 2371° / 57°0
71 °
Merrimac, Sunday, 23 August
Partly cloudy. High 71°, low 57°.
Pressure29.77 inHg
Wind15.8 mph NW
Humidity47%
Visibility—
Dew point44°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2478° / 62°0.08
78 °
Merrimac, Monday, 24 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.08 in
Chance of precipitation28%
Record high91° (2007)
Record low52° (1971)
Tue, 2578° / 62°0.12
78 °
Merrimac, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.12 in
Chance of precipitation27%
Record high96° (2007)
Record low53° (1971)
Wed, 2680° / 62°0.04
80 °
Merrimac, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high80°
Average low62°
Average precipitation0.04 in
Chance of precipitation20%
Record high95° (1993)
Record low52° (1981)
Thu, 2780° / 63°0.08
80 °
Merrimac, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.08 in
Chance of precipitation33%
Record high97° (1993)
Record low51° (1989)
Fri, 2879° / 63°0.12
79 °
Merrimac, Friday, 28 August
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.12 in
Chance of precipitation27%
Record high95° (1993)
Record low53° (1986)
Sat, 2978° / 63°0.15
78 °
Merrimac, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high78°
Average low63°
Average precipitation0.15 in
Chance of precipitation28%
Record high93° (2018)
Record low48° (1982)
Sun, 3079° / 62°0.11
79 °
Merrimac, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.11 in
Chance of precipitation25%
Record high94° (1973)
Record low47° (1965)
Mon, 3178° / 61°0.09
78 °
Merrimac, Monday, 31 August
Climate normal for this date — 60-year average.
Average high78°
Average low61°
Average precipitation0.09 in
Chance of precipitation28%
Record high93° (2010)
Record low46° (1965)
Tue, 0177° / 61°0.05
77 °
Merrimac, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high77°
Average low61°
Average precipitation0.05 in
Chance of precipitation23%
Record high94° (2010)
Record low49° (1975)
Wed, 0276° / 60°0.14
76 °
Merrimac, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.14 in
Chance of precipitation27%
Record high94° (2010)
Record low49° (2017)
Thu, 0376° / 60°0.11
76 °
Merrimac, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.11 in
Chance of precipitation35%
Record high93° (1973)
Record low51° (1967)
Fri, 0477° / 60°0.11
77 °
Merrimac, Friday, 4 September
Climate normal for this date — 60-year average.
Average high77°
Average low60°
Average precipitation0.11 in
Chance of precipitation23%
Record high90° (1973)
Record low50° (1987)
Sat, 0576° / 60°0.08
76 °
Merrimac, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.08 in
Chance of precipitation22%
Record high92° (2018)
Record low49° (1994)
Sun, 0675° / 60°0.13
75 °
Merrimac, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high75°
Average low60°
Average precipitation0.13 in
Chance of precipitation27%
Record high94° (2018)
Record low49° (2000)
About the monthly outlook
How accurate is a 30-day forecast?
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Merrimac, MA are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
What does "above normal" mean?
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
Where do the 66-year records come from?
They are real temperature extremes recorded in Merrimac, MA since 1960: the highest and lowest reading for each calendar date, with the year it happened.
How often is it updated?
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.