Monthly outlook for Wentzville, MO: average high 98.7°, average low 72.9°. That is 7.4° above the climate normal for August. Precipitation is expected on 6 days (about 0.9 inches), against a normal of 5 days and 1.7 inches. The warmest day looks like 20 August (114.1°), the coolest 14 August (65°).
98.7°/72.9°
Average high / low
+7.4°
Above normal
6 / 5
Wet days / normal
0.9 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
92.4°
85.5°
+3.8°
19 August – 28 August
109.3°
85.6°
+13.1°
29 August – 7 September
at normal
83.3°
—
August records over 66 years
103.6°14 August 2007All-time high
51.4°29 August 1986All-time low
Climate normals and records are computed from the nearest reference point — O'Fallon (8 mi).
Mon, 10100° / 70°0.45
100 °
Wentzville, Monday, 10 August
Heavy rain. High 100°, low 70°.
Pressure29.91 inHg
Wind12.3 mph SW
Humidity41%
Visibility6.2 mi
Dew point68°
Tue, 11102° / 69°0.04
102 °
Wentzville, Tuesday, 11 August
Light rain. High 102°, low 69°.
Pressure29.85 inHg
Wind12.5 mph SW
Humidity41%
Visibility6.2 mi
Dew point68°
Wed, 1296° / 75°0.02
96 °
Wentzville, Wednesday, 12 August
Light rain. High 96°, low 75°.
Pressure29.83 inHg
Wind6.9 mph NW
Humidity48%
Visibility6.2 mi
Dew point69°
Thu, 1389° / 73°0.08
89 °
Wentzville, Thursday, 13 August
Light rain. High 89°, low 73°.
Pressure29.88 inHg
Wind13.2 mph E
Humidity57%
Visibility—
Dew point69°
Fri, 1474° / 65°0.05
74 °
Wentzville, Friday, 14 August
Light rain. High 74°, low 65°.
Pressure30.06 inHg
Wind13 mph E
Humidity83%
Visibility—
Dew point64°
Sat, 1588° / 66°0.07
88 °
Wentzville, Saturday, 15 August
Light rain. High 88°, low 66°.
Pressure30.12 inHg
Wind10.3 mph E
Humidity75%
Visibility—
Dew point68°
Sun, 1693° / 71°0
93 °
Wentzville, Sunday, 16 August
Overcast. High 93°, low 71°.
Pressure30.03 inHg
Wind8.9 mph NE
Humidity56%
Visibility—
Dew point70°
Mon, 1788° / 70°0.03
88 °
Wentzville, Monday, 17 August
Light rain. High 88°, low 70°.
Pressure30.06 inHg
Wind8.6 mph E
Humidity56%
Visibility—
Dew point67°
Tue, 1897° / 69°0.01
97 °
Wentzville, Tuesday, 18 August
Light rain. High 97°, low 69°.
Pressure29.94 inHg
Wind9.7 mph E
Humidity52%
Visibility—
Dew point68°
Wed, 19113° / 76°0
113 °
Wentzville, Wednesday, 19 August
Clear. High 113°, low 76°.
Pressure29.85 inHg
Wind14.5 mph S
Humidity21%
Visibility—
Dew point55°
Thu, 20114° / 83°0
114 °
Wentzville, Thursday, 20 August
Clear. High 114°, low 83°.
Pressure29.80 inHg
Wind14.1 mph SW
Humidity17%
Visibility—
Dew point53°
Fri, 21109° / 79°0
109 °
Wentzville, Friday, 21 August
Clear. High 109°, low 79°.
Pressure29.85 inHg
Wind9.5 mph E
Humidity23%
Visibility—
Dew point56°
Sat, 22112° / 78°0.02
112 °
Wentzville, Saturday, 22 August
Light rain. High 112°, low 78°.
Pressure29.83 inHg
Wind10.8 mph S
Humidity20%
Visibility—
Dew point55°
Sun, 23108° / 75°0.07
108 °
Wentzville, Sunday, 23 August
Light rain. High 108°, low 75°.
Pressure29.85 inHg
Wind10.3 mph SW
Humidity27%
Visibility—
Dew point60°
Mon, 24100° / 74°0.03
100 °
Wentzville, Monday, 24 August
Light rain. High 100°, low 74°.
Pressure29.97 inHg
Wind12.5 mph N
Humidity43%
Visibility—
Dew point66°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2587° / 69°0.06
87 °
Wentzville, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high87°
Average low69°
Average precipitation0.06 in
Chance of precipitation23%
Record high101° (2023)
Record low57° (2015)
Wed, 2686° / 69°0.15
86 °
Wentzville, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.15 in
Chance of precipitation25%
Record high99° (2003)
Record low54° (2025)
Thu, 2786° / 69°0.08
86 °
Wentzville, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.08 in
Chance of precipitation25%
Record high98° (1983)
Record low58° (2015)
Fri, 2886° / 69°0.08
86 °
Wentzville, Friday, 28 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.08 in
Chance of precipitation28%
Record high97° (2000)
Record low55° (1967)
Sat, 2985° / 68°0.07
85 °
Wentzville, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high85°
Average low68°
Average precipitation0.07 in
Chance of precipitation28%
Record high98° (1984)
Record low51° (1986)
Sun, 3084° / 68°0.13
84 °
Wentzville, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high84°
Average low68°
Average precipitation0.13 in
Chance of precipitation27%
Record high98° (2013)
Record low53° (1986)
Mon, 3184° / 68°0.11
84 °
Wentzville, Monday, 31 August
Climate normal for this date — 60-year average.
Average high84°
Average low68°
Average precipitation0.11 in
Chance of precipitation30%
Record high101° (2013)
Record low56° (1967)
Tue, 0183° / 67°0.11
83 °
Wentzville, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.11 in
Chance of precipitation28%
Record high99° (2011)
Record low52° (1967)
Wed, 0283° / 67°0.13
83 °
Wentzville, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.13 in
Chance of precipitation37%
Record high97° (2011)
Record low52° (1974)
Thu, 0383° / 67°0.07
83 °
Wentzville, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.07 in
Chance of precipitation25%
Record high96° (2011)
Record low49° (1974)
Fri, 0482° / 66°0.09
82 °
Wentzville, Friday, 4 September
Climate normal for this date — 60-year average.
Average high82°
Average low66°
Average precipitation0.09 in
Chance of precipitation27%
Record high96° (1960)
Record low49° (1974)
Sat, 0583° / 65°0.04
83 °
Wentzville, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high83°
Average low65°
Average precipitation0.04 in
Chance of precipitation17%
Record high97° (1998)
Record low51° (1974)
Sun, 0683° / 65°0.05
83 °
Wentzville, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high83°
Average low65°
Average precipitation0.05 in
Chance of precipitation23%
Record high98° (1990)
Record low53° (2017)
Mon, 0783° / 65°0.07
83 °
Wentzville, Monday, 7 September
Climate normal for this date — 60-year average.
Average high83°
Average low65°
Average precipitation0.07 in
Chance of precipitation23%
Record high96° (1960)
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 Wentzville, MO 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 Wentzville, MO 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.