Monthly outlook for Sweetwater, IL: average high 91.7°, average low 70.9°. That is 5.1° above the climate normal for August. Precipitation is expected on 5 days (about 1.3 inches), against a normal of 5 days and 1.7 inches. The warmest day looks like 20 August (112.6°), the coolest 14 August (62.5°).
91.7°/70.9°
Average high / low
+5.1°
Above normal
5 / 5
Wet days / normal
1.3 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
86°
82.5°
+1.9°
19 August – 28 August
101.2°
82.9°
+10.2°
29 August – 7 September
at normal
81.4°
—
August records over 66 years
98.1°3 August 1964All-time high
46.2°29 August 1986All-time low
Climate normals and records are computed from the nearest reference point — Broadwell (13 mi).
Mon, 1097° / 79°0
97 °
Sweetwater, Monday, 10 August
Partly cloudy. High 97°, low 79°.
Pressure29.91 inHg
Wind11.2 mph SW
Humidity48%
Visibility6.2 mi
Dew point69°
Tue, 1197° / 68°0.03
97 °
Sweetwater, Tuesday, 11 August
Light rain. High 97°, low 68°.
Pressure29.83 inHg
Wind15.7 mph SW
Humidity47%
Visibility6.2 mi
Dew point70°
Wed, 1288° / 72°0.13
88 °
Sweetwater, Wednesday, 12 August
Light rain. High 88°, low 72°.
Pressure29.83 inHg
Wind3.7 mph N
Humidity70%
Visibility6.2 mi
Dew point73°
Thu, 1384° / 68°0
84 °
Sweetwater, Thursday, 13 August
Overcast. High 84°, low 68°.
Pressure29.94 inHg
Wind12.6 mph E
Humidity57%
Visibility—
Dew point65°
Fri, 1471° / 62°0.55
71 °
Sweetwater, Friday, 14 August
Rain. High 71°, low 62°.
Pressure30.12 inHg
Wind12.3 mph E
Humidity94%
Visibility—
Dew point62°
Sat, 1577° / 63°0.29
77 °
Sweetwater, Saturday, 15 August
Light rain. High 77°, low 63°.
Pressure30.15 inHg
Wind11.9 mph SE
Humidity73%
Visibility—
Dew point66°
Sun, 1682° / 66°0.08
82 °
Sweetwater, Sunday, 16 August
Light rain. High 82°, low 66°.
Pressure30.06 inHg
Wind7.8 mph E
Humidity72%
Visibility—
Dew point70°
Mon, 1784° / 67°0
84 °
Sweetwater, Monday, 17 August
Overcast. High 84°, low 67°.
Pressure30.06 inHg
Wind6.8 mph E
Humidity57%
Visibility—
Dew point64°
Tue, 1886° / 66°0
86 °
Sweetwater, Tuesday, 18 August
Overcast. High 86°, low 66°.
Pressure30.00 inHg
Wind9.6 mph SE
Humidity50%
Visibility—
Dew point61°
Wed, 1999° / 74°0
99 °
Sweetwater, Wednesday, 19 August
Partly cloudy. High 99°, low 74°.
Pressure29.85 inHg
Wind16.4 mph S
Humidity47%
Visibility—
Dew point69°
Thu, 20113° / 80°0
113 °
Sweetwater, Thursday, 20 August
Overcast. High 113°, low 80°.
Pressure29.77 inHg
Wind13.6 mph W
Humidity19%
Visibility—
Dew point54°
Fri, 2196° / 75°0
96 °
Sweetwater, Friday, 21 August
Overcast. High 96°, low 75°.
Pressure29.88 inHg
Wind11.3 mph E
Humidity58%
Visibility—
Dew point73°
Sat, 22107° / 74°0
107 °
Sweetwater, Saturday, 22 August
Clear. High 107°, low 74°.
Pressure29.83 inHg
Wind12.8 mph S
Humidity27%
Visibility—
Dew point60°
Sun, 23105° / 80°0.02
105 °
Sweetwater, Sunday, 23 August
Light rain. High 105°, low 80°.
Pressure29.83 inHg
Wind18.1 mph S
Humidity31%
Visibility—
Dew point61°
Mon, 2488° / 71°0.22
88 °
Sweetwater, Monday, 24 August
Rain. High 88°, low 71°.
Pressure30.00 inHg
Wind15 mph NE
Humidity61%
Visibility—
Dew point69°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2583° / 66°0.1
83 °
Sweetwater, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high83°
Average low66°
Average precipitation0.1 in
Chance of precipitation32%
Record high94° (2014)
Record low55° (1966)
Wed, 2683° / 67°0.11
83 °
Sweetwater, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.11 in
Chance of precipitation33%
Record high94° (2003)
Record low52° (2025)
Thu, 2783° / 67°0.09
83 °
Sweetwater, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.09 in
Chance of precipitation30%
Record high94° (2013)
Record low53° (2025)
Fri, 2883° / 66°0.11
83 °
Sweetwater, Friday, 28 August
Climate normal for this date — 60-year average.
Average high83°
Average low66°
Average precipitation0.11 in
Chance of precipitation28%
Record high96° (2013)
Record low50° (1986)
Sat, 2983° / 66°0.09
83 °
Sweetwater, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high83°
Average low66°
Average precipitation0.09 in
Chance of precipitation27%
Record high95° (1984)
Record low46° (1986)
Sun, 3082° / 65°0.07
82 °
Sweetwater, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.07 in
Chance of precipitation18%
Record high96° (2013)
Record low50° (1986)
Mon, 3182° / 65°0.08
82 °
Sweetwater, Monday, 31 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.08 in
Chance of precipitation28%
Record high97° (2013)
Record low53° (1967)
Tue, 0182° / 65°0.18
82 °
Sweetwater, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.18 in
Chance of precipitation25%
Record high99° (2011)
Record low49° (1967)
Wed, 0282° / 65°0.09
82 °
Sweetwater, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.09 in
Chance of precipitation20%
Record high97° (2011)
Record low49° (2017)
Thu, 0382° / 64°0.07
82 °
Sweetwater, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high82°
Average low64°
Average precipitation0.07 in
Chance of precipitation23%
Record high95° (2011)
Record low47° (1974)
Fri, 0480° / 63°0.1
80 °
Sweetwater, Friday, 4 September
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.1 in
Chance of precipitation27%
Record high94° (2007)
Record low47° (1974)
Sat, 0581° / 63°0.04
81 °
Sweetwater, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high81°
Average low63°
Average precipitation0.04 in
Chance of precipitation20%
Record high94° (1990)
Record low50° (1974)
Sun, 0680° / 63°0.06
80 °
Sweetwater, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high80°
Average low63°
Average precipitation0.06 in
Chance of precipitation25%
Record high95° (1990)
Record low48° (1962)
Mon, 0781° / 63°0.09
81 °
Sweetwater, Monday, 7 September
Climate normal for this date — 60-year average.
Average high81°
Average low63°
Average precipitation0.09 in
Chance of precipitation20%
Record high94° (2015)
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 Sweetwater, 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 Sweetwater, 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.