Des Moines, IA weather in August
August in Des Moines: warm and often humid, with some rain. Highs 84°F, lows 64°F, about 9 wet days. This is the peak of the warm season in Des Moines.
- Normal high
- 84°F
- Normal low
- 64°F
- Wet days
- 9
- 4.2 in total
- Muggy days
- 14
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 85°F | 81°F |
| Normal low | 66°F | 61°F |
| Chance of a wet day | 31% | 29% |
| Sunrise / sunset | 6:09 am / 8:32 pm | 6:39 am / 7:49 pm |
| Daylight | 14.4 h | 13.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Central Time).
A typical August day
- 6 am66°Fdew point 62°F
- 9 am73°Fdew point 64°F
- Noon80°Fdew point 64°F
- 3 pm82°Fdew point 64°F
- 6 pm80°Fdew point 64°F
- 9 pm73°Fdew point 64°F
NOAA hourly normals (local standard time) from Des Moines Intl Airport (5 mi away); average wind 8 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F5 of 31
- Hot dayshigh 90°F or more6 of 31
- Muggy daysdaily mean dew point 65°F or more14 of 31
- Wet daysat least 0.01 in of rain or melted snow9 of 31
- Notable rainat least 0.10 in6 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 4.2 in; a dry August brings about 2.0 in and a wet one about 5.6 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20201995: average high 89°F
- Coolest August2004: average high 78°F
- Wettest August1993: 12.2 in
- Driest August2003: 0.7 in
- Highest reading104°F (August 30, 2013)
- Lowest reading46°F (August 31, 1992)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 86°F | 84°F | 77°F |
| Normal low | 66°F | 64°F | 55°F |
| Wet days | 10 | 9 | 8 |
| Comfortable days | 3 | 5 | 14 |
| Daylight | 14.8 h | 13.8 h | 12.5 h |
Highs change by -2°F from July and -7°F into September.
Nearby alternatives in August
- Warmer: Kansas City, MO180 mi · high 89°F · 8 wet days
- Cooler: Rochester, MN177 mi · high 78°F · 10 wet days
How Des Moines ranks in August
- Normal high239th warmest of 378 cities; 2nd of 3 in Iowa
- Wet days210th driest of 378
- Comfortable days130th most of 341
What to pack for Des Moines in August
- A rain jacket or umbrella – rain on about 9 days
Heating and cooling
August has 4 heating degree days and 280 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Des Moines in August?
The normal high is 84°F and the normal low is 64°F. From 1991 to 2020 the hottest August reading was 104°F (August 30, 2013).
Does it rain a lot in Des Moines in August?
About 9 days in August have at least 0.01 in of precipitation, and the normal total is 4.2 in. The wettest August in 1991-2020 was in 1993 (12.2 in); the driest was in 2003 (0.7 in).
Is August a good time to visit Des Moines?
August ranks 6th of 12 months on our comfort score for Des Moines (55 out of 100). It has about 5 comfortable days and about 6 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates and humidity and wind by hour: Des Moines Intl Airport (USW00014933), 5.1 mi SSW of the city center, 957 ft (85 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Des Moines International Airport (725460-14933), 5.1 mi SSW of the city center, 939 ft (67 ft higher than the city). Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).