Monthly outlook for Crestwood, IL: average high 80.1°, average low 65.2°. That is 0.2° above the climate normal for August. Precipitation is expected on 4 days (about 0.6 inches), against a normal of 6 days and 1.9 inches. The warmest day looks like 10 August (88.4°), the coolest 21 August (57.3°).
80.1°/65.2°
Average high / low
+0.2°
Above normal
4 / 6
Wet days / normal
0.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
81.7°
79.9°
+1°
19 August – 28 August
77.6°
79.9°
-1.3°
29 August – 7 September
at normal
78.2°
—
August records over 66 years
98.1°24 August 2023All-time high
49.1°29 August 1965All-time low
Climate normals and records are computed from the nearest reference point — Blue Island (3 mi).
Mon, 1088° / 72°0.31
88 °
Crestwood, Monday, 10 August
Rain. High 88°, low 72°.
Pressure29.91 inHg
Wind2.9 mph S
Humidity60%
Visibility6.2 mi
Dew point71°
Tue, 1184° / 72°0.06
84 °
Crestwood, Tuesday, 11 August
Light rain. High 84°, low 72°.
Pressure29.83 inHg
Wind10.8 mph SW
Humidity88%
Visibility6.2 mi
Dew point72°
Wed, 1284° / 69°0
84 °
Crestwood, Wednesday, 12 August
Light rain. High 84°, low 69°.
Pressure29.85 inHg
Wind4.1 mph N
Humidity51%
Visibility6.2 mi
Dew point65°
Thu, 1376° / 66°0
76 °
Crestwood, Thursday, 13 August
Overcast. High 76°, low 66°.
Pressure30.00 inHg
Wind7.4 mph NE
Humidity46%
Visibility—
Dew point53°
Fri, 1481° / 62°0
81 °
Crestwood, Friday, 14 August
Clear. High 81°, low 62°.
Pressure30.09 inHg
Wind9.5 mph NE
Humidity37%
Visibility—
Dew point50°
Sat, 1571° / 64°0.01
71 °
Crestwood, Saturday, 15 August
Light rain. High 71°, low 64°.
Pressure30.27 inHg
Wind7.5 mph SW
Humidity57%
Visibility—
Dew point52°
Sun, 1678° / 65°0
78 °
Crestwood, Sunday, 16 August
Overcast. High 78°, low 65°.
Pressure30.12 inHg
Wind5.5 mph S
Humidity52%
Visibility—
Dew point55°
Mon, 1783° / 66°0
83 °
Crestwood, Monday, 17 August
Overcast. High 83°, low 66°.
Pressure30.03 inHg
Wind7.2 mph SW
Humidity55%
Visibility—
Dew point61°
Tue, 1884° / 67°0
84 °
Crestwood, Tuesday, 18 August
Overcast. High 84°, low 67°.
Pressure29.97 inHg
Wind9.8 mph SW
Humidity58%
Visibility—
Dew point64°
Wed, 1975° / 67°0.04
75 °
Crestwood, Wednesday, 19 August
Light rain. High 75°, low 67°.
Pressure29.91 inHg
Wind11.7 mph NW
Humidity52%
Visibility—
Dew point55°
Thu, 2069° / 60°0.01
69 °
Crestwood, Thursday, 20 August
Light rain. High 69°, low 60°.
Pressure30.06 inHg
Wind9.3 mph N
Humidity58%
Visibility—
Dew point51°
Fri, 2178° / 57°0
78 °
Crestwood, Friday, 21 August
Clear. High 78°, low 57°.
Pressure30.06 inHg
Wind8.3 mph NE
Humidity40%
Visibility—
Dew point49°
Sat, 2273° / 59°0
73 °
Crestwood, Saturday, 22 August
Overcast. High 73°, low 59°.
Pressure29.88 inHg
Wind9.5 mph S
Humidity66%
Visibility—
Dew point56°
Sun, 2385° / 65°0
85 °
Crestwood, Sunday, 23 August
Clear. High 85°, low 65°.
Pressure29.91 inHg
Wind12.3 mph W
Humidity39%
Visibility—
Dew point55°
Mon, 2486° / 65°0
86 °
Crestwood, Monday, 24 August
Overcast. High 86°, low 65°.
Pressure30.00 inHg
Wind7.5 mph SW
Humidity40%
Visibility—
Dew point56°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2580° / 66°0.07
80 °
Crestwood, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high80°
Average low66°
Average precipitation0.07 in
Chance of precipitation27%
Record high92° (2021)
Record low53° (2017)
Wed, 2681° / 67°0.17
81 °
Crestwood, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high81°
Average low67°
Average precipitation0.17 in
Chance of precipitation35%
Record high94° (2024)
Record low54° (2025)
Thu, 2780° / 67°0.14
80 °
Crestwood, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high80°
Average low67°
Average precipitation0.14 in
Chance of precipitation37%
Record high96° (2024)
Record low54° (2025)
Fri, 2880° / 67°0.15
80 °
Crestwood, Friday, 28 August
Climate normal for this date — 60-year average.
Average high80°
Average low67°
Average precipitation0.15 in
Chance of precipitation37%
Record high92° (1984)
Record low51° (1986)
Sat, 2980° / 66°0.1
80 °
Crestwood, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high80°
Average low66°
Average precipitation0.1 in
Chance of precipitation28%
Record high92° (1984)
Record low49° (1965)
Sun, 3079° / 65°0.09
79 °
Crestwood, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high79°
Average low65°
Average precipitation0.09 in
Chance of precipitation30%
Record high92° (2013)
Record low54° (1986)
Mon, 3178° / 65°0.06
78 °
Crestwood, Monday, 31 August
Climate normal for this date — 60-year average.
Average high78°
Average low65°
Average precipitation0.06 in
Chance of precipitation23%
Record high89° (2012)
Record low55° (2023)
Tue, 0178° / 65°0.13
78 °
Crestwood, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high78°
Average low65°
Average precipitation0.13 in
Chance of precipitation30%
Record high94° (2011)
Record low54° (1967)
Wed, 0279° / 65°0.06
79 °
Crestwood, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high79°
Average low65°
Average precipitation0.06 in
Chance of precipitation27%
Record high92° (2011)
Record low52° (1965)
Thu, 0379° / 65°0.07
79 °
Crestwood, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high79°
Average low65°
Average precipitation0.07 in
Chance of precipitation23%
Record high93° (2023)
Record low53° (1974)
Fri, 0477° / 64°0.09
77 °
Crestwood, Friday, 4 September
Climate normal for this date — 60-year average.
Average high77°
Average low64°
Average precipitation0.09 in
Chance of precipitation33%
Record high91° (2023)
Record low50° (2025)
Sat, 0577° / 63°0.07
77 °
Crestwood, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high77°
Average low63°
Average precipitation0.07 in
Chance of precipitation27%
Record high90° (2023)
Record low53° (2010)
Sun, 0677° / 64°0.1
77 °
Crestwood, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high77°
Average low64°
Average precipitation0.1 in
Chance of precipitation37%
Record high91° (1990)
Record low49° (2025)
Mon, 0777° / 63°0.13
77 °
Crestwood, Monday, 7 September
Climate normal for this date — 60-year average.
Average high77°
Average low63°
Average precipitation0.13 in
Chance of precipitation30%
Record high92° (1960)
Record low48° (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 Crestwood, 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 Crestwood, 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.