Monthly outlook for Northfield, IL: average high 78.4°, average low 66.7°. That is 0.2° below the climate normal for August. Precipitation is expected on 7 days (about 2.4 inches), against a normal of 6 days and 1.9 inches. The warmest day looks like 19 August (84.7°), the coolest 23 August (58.5°).
78.4°/66.7°
Average high / low
−0.2°
Below normal
7 / 6
Wet days / normal
2.4 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
80.3°
79.1°
+0.7°
18 August – 27 August
75.4°
78.8°
-1.9°
28 August – 6 September
at normal
77.3°
—
August records over 66 years
99.3°24 August 2023All-time high
50.2°22 August 2024All-time low
Climate normals and records are computed from the nearest reference point — Skokie (5 mi).
Sun, 0983° / 66°1.24
83 °
Northfield, Sunday, 9 August
Heavy rain. High 83°, low 66°.
Pressure29.94 inHg
Wind2.4 mph NE
Humidity92%
Visibility4.2 mi
Dew point63°
Mon, 1084° / 73°0.19
84 °
Northfield, Monday, 10 August
Heavy rain. High 84°, low 73°.
Pressure29.88 inHg
Wind4.3 mph S
Humidity83%
Visibility6.2 mi
Dew point69°
Tue, 1182° / 72°0.37
82 °
Northfield, Tuesday, 11 August
Rain. High 82°, low 72°.
Pressure29.80 inHg
Wind6.4 mph NW
Humidity72%
Visibility6.2 mi
Dew point71°
Wed, 1285° / 69°0.02
85 °
Northfield, Wednesday, 12 August
Light rain. High 85°, low 69°.
Pressure29.85 inHg
Wind1.4 mph E
Humidity59%
Visibility6.2 mi
Dew point64°
Thu, 1373° / 66°0.07
73 °
Northfield, Thursday, 13 August
Light rain. High 73°, low 66°.
Pressure29.97 inHg
Wind11.6 mph NE
Humidity65%
Visibility—
Dew point59°
Fri, 1473° / 64°0
73 °
Northfield, Friday, 14 August
Clear. High 73°, low 64°.
Pressure30.18 inHg
Wind10.9 mph NE
Humidity48%
Visibility—
Dew point51°
Sat, 1578° / 62°0
78 °
Northfield, Saturday, 15 August
Overcast. High 78°, low 62°.
Pressure30.30 inHg
Wind6.2 mph E
Humidity38%
Visibility—
Dew point47°
Sun, 1682° / 63°0
82 °
Northfield, Sunday, 16 August
Overcast. High 82°, low 63°.
Pressure30.18 inHg
Wind9.5 mph SW
Humidity39%
Visibility—
Dew point51°
Mon, 1782° / 69°0.04
82 °
Northfield, Monday, 17 August
Light rain. High 82°, low 69°.
Pressure30.00 inHg
Wind6.7 mph S
Humidity84%
Visibility—
Dew point65°
Tue, 1879° / 71°0.01
79 °
Northfield, Tuesday, 18 August
Light rain. High 79°, low 71°.
Pressure30.03 inHg
Wind8.7 mph NE
Humidity63%
Visibility—
Dew point64°
Wed, 1985° / 69°0.43
85 °
Northfield, Wednesday, 19 August
Rain. High 85°, low 69°.
Pressure29.91 inHg
Wind5.3 mph S
Humidity51%
Visibility—
Dew point62°
Thu, 2075° / 69°0.01
75 °
Northfield, Thursday, 20 August
Light rain. High 75°, low 69°.
Pressure29.91 inHg
Wind10.4 mph NE
Humidity73%
Visibility—
Dew point64°
Fri, 2175° / 66°0
75 °
Northfield, Friday, 21 August
Partly cloudy. High 75°, low 66°.
Pressure29.97 inHg
Wind10.2 mph NE
Humidity63%
Visibility—
Dew point60°
Sat, 2275° / 62°0.06
75 °
Northfield, Saturday, 22 August
Light rain. High 75°, low 62°.
Pressure29.97 inHg
Wind17.6 mph NE
Humidity80%
Visibility—
Dew point59°
Sun, 2364° / 59°0
64 °
Northfield, Sunday, 23 August
Clear. High 64°, low 59°.
Pressure30.27 inHg
Wind15.4 mph NE
Humidity51%
Visibility—
Dew point45°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2479° / 68°0.12
79 °
Northfield, Monday, 24 August
Climate normal for this date — 60-year average.
Average high79°
Average low68°
Average precipitation0.12 in
Chance of precipitation28%
Record high99° (2023)
Record low58° (1966)
Tue, 2579° / 67°0.07
79 °
Northfield, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high79°
Average low67°
Average precipitation0.07 in
Chance of precipitation23%
Record high92° (2024)
Record low53° (2017)
Wed, 2680° / 68°0.15
80 °
Northfield, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high80°
Average low68°
Average precipitation0.15 in
Chance of precipitation33%
Record high96° (2024)
Record low55° (2025)
Thu, 2779° / 69°0.11
79 °
Northfield, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high79°
Average low69°
Average precipitation0.11 in
Chance of precipitation32%
Record high98° (2024)
Record low56° (2025)
Fri, 2879° / 68°0.13
79 °
Northfield, Friday, 28 August
Climate normal for this date — 60-year average.
Average high79°
Average low68°
Average precipitation0.13 in
Chance of precipitation35%
Record high91° (2021)
Record low53° (1986)
Sat, 2979° / 67°0.11
79 °
Northfield, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high79°
Average low67°
Average precipitation0.11 in
Chance of precipitation30%
Record high91° (1984)
Record low53° (1965)
Sun, 3078° / 67°0.13
78 °
Northfield, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high78°
Average low67°
Average precipitation0.13 in
Chance of precipitation27%
Record high91° (2013)
Record low57° (1965)
Mon, 3177° / 66°0.07
77 °
Northfield, Monday, 31 August
Climate normal for this date — 60-year average.
Average high77°
Average low66°
Average precipitation0.07 in
Chance of precipitation22%
Record high89° (2012)
Record low56° (2023)
Tue, 0177° / 66°0.12
77 °
Northfield, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high77°
Average low66°
Average precipitation0.12 in
Chance of precipitation32%
Record high90° (2011)
Record low56° (1987)
Wed, 0278° / 66°0.05
78 °
Northfield, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high78°
Average low66°
Average precipitation0.05 in
Chance of precipitation23%
Record high88° (2023)
Record low52° (2017)
Thu, 0377° / 66°0.08
77 °
Northfield, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high77°
Average low66°
Average precipitation0.08 in
Chance of precipitation30%
Record high94° (2023)
Record low54° (1974)
Fri, 0476° / 65°0.09
76 °
Northfield, Friday, 4 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.09 in
Chance of precipitation30%
Record high93° (2023)
Record low50° (2025)
Sat, 0576° / 65°0.09
76 °
Northfield, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.09 in
Chance of precipitation22%
Record high91° (2023)
Record low55° (2017)
Sun, 0676° / 65°0.1
76 °
Northfield, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.1 in
Chance of precipitation35%
Record high90° (1990)
Record low50° (2025)
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 Northfield, IL 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 Northfield, IL 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.