Monthly outlook for Hillsdale, IL: average high 84.9°, average low 67.7°. That is 2.3° above the climate normal for August. Precipitation is expected on 6 days (about 1.6 inches), against a normal of 5 days and 1.8 inches. The warmest day looks like 22 August (94°), the coolest 15 August (61°).
84.9°/67.7°
Average high / low
+2.3°
Above normal
6 / 5
Wet days / normal
1.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
81.6°
80.8°
+0.4°
19 August – 28 August
90.5°
81°
+5.3°
29 August – 7 September
at normal
79.2°
—
August records over 66 years
101.5°16 August 1988All-time high
46.8°29 August 1986All-time low
Climate normals and records are computed from the nearest reference point — Princeton (10 mi).
Mon, 1089° / 71°0.02
89 °
Hillsdale, Monday, 10 August
Light rain. High 89°, low 71°.
Pressure29.88 inHg
Wind2.4 mph SE
Humidity76%
Visibility6.2 mi
Dew point75°
Tue, 1189° / 69°0
89 °
Hillsdale, Tuesday, 11 August
Overcast. High 89°, low 69°.
Pressure29.80 inHg
Wind6.7 mph S
Humidity70%
Visibility6.2 mi
Dew point72°
Wed, 1284° / 68°0.05
84 °
Hillsdale, Wednesday, 12 August
Light rain. High 84°, low 68°.
Pressure29.83 inHg
Wind8.9 mph NE
Humidity69%
Visibility6.2 mi
Dew point71°
Thu, 1375° / 62°0.45
75 °
Hillsdale, Thursday, 13 August
Rain. High 75°, low 62°.
Pressure30.03 inHg
Wind10.1 mph NE
Humidity73%
Visibility—
Dew point64°
Fri, 1473° / 61°0.28
73 °
Hillsdale, Friday, 14 August
Rain. High 73°, low 61°.
Pressure30.15 inHg
Wind11.8 mph E
Humidity63%
Visibility—
Dew point57°
Sat, 1574° / 61°0.06
74 °
Hillsdale, Saturday, 15 August
Light rain. High 74°, low 61°.
Pressure30.21 inHg
Wind10.8 mph SE
Humidity66%
Visibility—
Dew point60°
Sun, 1677° / 66°0.03
77 °
Hillsdale, Sunday, 16 August
Light rain. High 77°, low 66°.
Pressure30.09 inHg
Wind5.5 mph E
Humidity83%
Visibility—
Dew point68°
Mon, 1782° / 65°0
82 °
Hillsdale, Monday, 17 August
Overcast. High 82°, low 65°.
Pressure30.09 inHg
Wind5.4 mph W
Humidity64%
Visibility—
Dew point65°
Tue, 1882° / 64°0
82 °
Hillsdale, Tuesday, 18 August
Overcast. High 82°, low 64°.
Pressure29.97 inHg
Wind11.3 mph S
Humidity70%
Visibility—
Dew point68°
Wed, 1992° / 70°0
92 °
Hillsdale, Wednesday, 19 August
Overcast. High 92°, low 70°.
Pressure29.83 inHg
Wind12.2 mph S
Humidity65%
Visibility—
Dew point72°
Thu, 2093° / 77°0
93 °
Hillsdale, Thursday, 20 August
Overcast. High 93°, low 77°.
Pressure29.77 inHg
Wind9.5 mph S
Humidity47%
Visibility—
Dew point66°
Fri, 2187° / 73°0
87 °
Hillsdale, Friday, 21 August
Mostly clear. High 87°, low 73°.
Pressure29.91 inHg
Wind13 mph NE
Humidity57%
Visibility—
Dew point67°
Sat, 2294° / 67°0
94 °
Hillsdale, Saturday, 22 August
Light rain. High 94°, low 67°.
Pressure29.83 inHg
Wind11.7 mph S
Humidity57%
Visibility—
Dew point71°
Sun, 2392° / 76°0.02
92 °
Hillsdale, Sunday, 23 August
Light rain. High 92°, low 76°.
Pressure29.80 inHg
Wind18.8 mph S
Humidity47%
Visibility—
Dew point67°
Mon, 2486° / 68°0.56
86 °
Hillsdale, Monday, 24 August
Rain. High 86°, low 68°.
Pressure30.03 inHg
Wind12.3 mph NE
Humidity69%
Visibility—
Dew point70°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2581° / 65°0.12
81 °
Hillsdale, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.12 in
Chance of precipitation32%
Record high94° (2003)
Record low53° (2025)
Wed, 2681° / 65°0.19
81 °
Hillsdale, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.19 in
Chance of precipitation30%
Record high94° (2003)
Record low51° (1964)
Thu, 2781° / 66°0.12
81 °
Hillsdale, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high81°
Average low66°
Average precipitation0.12 in
Chance of precipitation25%
Record high96° (2024)
Record low54° (1968)
Fri, 2881° / 65°0.17
81 °
Hillsdale, Friday, 28 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.17 in
Chance of precipitation35%
Record high94° (1984)
Record low47° (1986)
Sat, 2981° / 64°0.09
81 °
Hillsdale, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high81°
Average low64°
Average precipitation0.09 in
Chance of precipitation22%
Record high94° (1984)
Record low47° (1986)
Sun, 3080° / 64°0.07
80 °
Hillsdale, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.07 in
Chance of precipitation22%
Record high96° (2013)
Record low53° (2009)
Mon, 3180° / 63°0.09
80 °
Hillsdale, Monday, 31 August
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.09 in
Chance of precipitation23%
Record high94° (2000)
Record low47° (2009)
Tue, 0180° / 63°0.1
80 °
Hillsdale, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.1 in
Chance of precipitation30%
Record high95° (1984)
Record low47° (1967)
Wed, 0280° / 63°0.06
80 °
Hillsdale, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.06 in
Chance of precipitation28%
Record high92° (2000)
Record low49° (1967)
Thu, 0379° / 63°0.13
79 °
Hillsdale, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.13 in
Chance of precipitation33%
Record high93° (2023)
Record low49° (1974)
Fri, 0478° / 62°0.1
78 °
Hillsdale, Friday, 4 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.1 in
Chance of precipitation27%
Record high92° (2023)
Record low46° (1974)
Sat, 0578° / 61°0.07
78 °
Hillsdale, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high78°
Average low61°
Average precipitation0.07 in
Chance of precipitation22%
Record high92° (1990)
Record low49° (1974)
Sun, 0678° / 62°0.12
78 °
Hillsdale, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.12 in
Chance of precipitation28%
Record high93° (1960)
Record low46° (1962)
Mon, 0778° / 62°0.11
78 °
Hillsdale, Monday, 7 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.11 in
Chance of precipitation32%
Record high93° (1960)
Record low46° (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 Hillsdale, 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 Hillsdale, 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.