Monthly outlook for Northwest Harwinton, CT: average high 79.2°, average low 60.6°. That is 0.5° above the climate normal for August. Precipitation is expected on 4 days (about 0.9 inches), against a normal of 6 days and 2.5 inches. The warmest day looks like 24 August (85.6°), the coolest 15 August (53.5°).
79.2°/60.6°
Average high / low
+0.5°
Above normal
4 / 6
Wet days / normal
0.9 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
78.1°
79.3°
-0.6°
19 August – 28 August
81°
77.3°
+2.1°
29 August – 7 September
at normal
75.8°
—
August records over 66 years
97.2°2 August 1975All-time high
44.2°30 August 1986All-time low
Climate normals and records are computed from the nearest reference point — Plymouth (8 mi).
Mon, 1082° / 64°0.19
82 °
Northwest Harwinton, Monday, 10 August
Rain. High 82°, low 64°.
Pressure29.97 inHg
Wind7.4 mph SW
Humidity43%
Visibility6.2 mi
Dew point60°
Tue, 1182° / 64°0
82 °
Northwest Harwinton, Tuesday, 11 August
Partly cloudy. High 82°, low 64°.
Pressure29.85 inHg
Wind9.7 mph NW
Humidity42%
Visibility6.2 mi
Dew point55°
Wed, 1274° / 62°0.04
74 °
Northwest Harwinton, Wednesday, 12 August
Light rain. High 74°, low 62°.
Pressure29.80 inHg
Wind2.9 mph NE
Humidity66%
Visibility6.2 mi
Dew point60°
Thu, 1380° / 57°0
80 °
Northwest Harwinton, Thursday, 13 August
Clear. High 80°, low 57°.
Pressure29.83 inHg
Wind11.2 mph NW
Humidity47%
Visibility6.2 mi
Dew point55°
Fri, 1471° / 54°0
71 °
Northwest Harwinton, Friday, 14 August
Overcast. High 71°, low 54°.
Pressure30.09 inHg
Wind7.2 mph NW
Humidity44%
Visibility—
Dew point45°
Sat, 1577° / 54°0
77 °
Northwest Harwinton, Saturday, 15 August
Overcast. High 77°, low 54°.
Pressure30.18 inHg
Wind6.6 mph NW
Humidity42%
Visibility—
Dew point45°
Sun, 1673° / 59°0.46
73 °
Northwest Harwinton, Sunday, 16 August
Rain. High 73°, low 59°.
Pressure29.97 inHg
Wind15.5 mph S
Humidity99%
Visibility—
Dew point64°
Mon, 1775° / 59°0
75 °
Northwest Harwinton, Monday, 17 August
Partly cloudy. High 75°, low 59°.
Pressure29.88 inHg
Wind13.8 mph NW
Humidity63%
Visibility—
Dew point53°
Tue, 1881° / 58°0
81 °
Northwest Harwinton, Tuesday, 18 August
Mostly clear. High 81°, low 58°.
Pressure30.09 inHg
Wind8.8 mph S
Humidity43%
Visibility—
Dew point51°
Wed, 1981° / 64°0.2
81 °
Northwest Harwinton, Wednesday, 19 August
Light rain. High 81°, low 64°.
Pressure29.88 inHg
Wind11.1 mph NW
Humidity98%
Visibility—
Dew point68°
Thu, 2080° / 56°0
80 °
Northwest Harwinton, Thursday, 20 August
Overcast. High 80°, low 56°.
Pressure29.97 inHg
Wind7.5 mph W
Humidity45%
Visibility—
Dew point50°
Fri, 2179° / 66°0
79 °
Northwest Harwinton, Friday, 21 August
Overcast. High 79°, low 66°.
Pressure29.80 inHg
Wind11.8 mph SW
Humidity67%
Visibility—
Dew point64°
Sat, 2279° / 61°0
79 °
Northwest Harwinton, Saturday, 22 August
Overcast. High 79°, low 61°.
Pressure29.91 inHg
Wind5.3 mph NE
Humidity60%
Visibility—
Dew point56°
Sun, 2382° / 60°0
82 °
Northwest Harwinton, Sunday, 23 August
Mostly clear. High 82°, low 60°.
Pressure30.06 inHg
Wind8.7 mph S
Humidity60%
Visibility—
Dew point59°
Mon, 2486° / 61°0.03
86 °
Northwest Harwinton, Monday, 24 August
Light rain. High 86°, low 61°.
Pressure29.97 inHg
Wind9.5 mph W
Humidity65%
Visibility—
Dew point65°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2578° / 60°0.12
78 °
Northwest Harwinton, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high78°
Average low60°
Average precipitation0.12 in
Chance of precipitation28%
Record high90° (2020)
Record low48° (1971)
Wed, 2678° / 60°0.09
78 °
Northwest Harwinton, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high78°
Average low60°
Average precipitation0.09 in
Chance of precipitation28%
Record high90° (2021)
Record low49° (1963)
Thu, 2778° / 62°0.18
78 °
Northwest Harwinton, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.18 in
Chance of precipitation38%
Record high91° (1993)
Record low50° (1989)
Fri, 2878° / 62°0.21
78 °
Northwest Harwinton, Friday, 28 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.21 in
Chance of precipitation37%
Record high91° (2018)
Record low51° (1968)
Sat, 2977° / 61°0.17
77 °
Northwest Harwinton, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high77°
Average low61°
Average precipitation0.17 in
Chance of precipitation37%
Record high91° (2018)
Record low45° (1982)
Sun, 3077° / 60°0.09
77 °
Northwest Harwinton, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high77°
Average low60°
Average precipitation0.09 in
Chance of precipitation23%
Record high91° (1973)
Record low44° (1986)
Mon, 3177° / 60°0.07
77 °
Northwest Harwinton, Monday, 31 August
Climate normal for this date — 60-year average.
Average high77°
Average low60°
Average precipitation0.07 in
Chance of precipitation23%
Record high92° (1973)
Record low46° (1965)
Tue, 0176° / 60°0.13
76 °
Northwest Harwinton, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.13 in
Chance of precipitation27%
Record high92° (2010)
Record low48° (1975)
Wed, 0276° / 59°0.16
76 °
Northwest Harwinton, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high76°
Average low59°
Average precipitation0.16 in
Chance of precipitation30%
Record high93° (2010)
Record low47° (1991)
Thu, 0375° / 59°0.12
75 °
Northwest Harwinton, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high75°
Average low59°
Average precipitation0.12 in
Chance of precipitation38%
Record high90° (2018)
Record low46° (1967)
Fri, 0476° / 60°0.11
76 °
Northwest Harwinton, Friday, 4 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.11 in
Chance of precipitation25%
Record high91° (1973)
Record low48° (1987)
Sat, 0575° / 59°0.07
75 °
Northwest Harwinton, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high75°
Average low59°
Average precipitation0.07 in
Chance of precipitation27%
Record high91° (2018)
Record low47° (1989)
Sun, 0675° / 59°0.22
75 °
Northwest Harwinton, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high75°
Average low59°
Average precipitation0.22 in
Chance of precipitation32%
Record high93° (2018)
Record low46° (1989)
Mon, 0775° / 58°0.13
75 °
Northwest Harwinton, Monday, 7 September
Climate normal for this date — 60-year average.
Average high75°
Average low58°
Average precipitation0.13 in
Chance of precipitation32%
Record high93° (2023)
Record low44° (1984)
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 Northwest Harwinton, CT 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 Northwest Harwinton, CT 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.