Marshalltown weather in August: Marshalltown, Iowa: normal highs, lows, rain and records for August
Marshalltown in August has a normal high of 81°F and a normal low of 60°F, a daily mean of 70°F, falling from 83°F on the 1st to 79°F by the 31st. Measurable precipitation falls on 12 days in a normal August, 3.88 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 15°C, 99 mm of precipitation in August.
- NOAA stationMarshalltown Municipal Airport
- Station IDUSW00094988
- Location42.11°N 92.92°W
- Elevation974 ft (297 m)
- From the center5 miles
- Population27,886
- Jan 28° 10°
- Feb 32° 14°
- Mar 46° 26°
- Apr 60° 37°
- May 71° 49°
- Jun 81° 59°
- Jul 83° 62°
- Aug 81° 60°
- Sep 75° 51°
- Oct 62° 39°
- Nov 46° 26°
- Dec 33° 16°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Marshalltown in August?
The normal high is 81°F and the normal low 60°F, for a daily mean of 70.2°F. August is 2.4°F cooler than July and 7.4°F warmer than September. August is the 2nd warmest month of the year in Marshalltown and the 3rd wettest. Across the month the normal high falls 4°F, from 83°F on August 1 to 79°F on August 31. From one year to the next August's mean temperature typically moves about 2.5°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 68°F and 73°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 39%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 83°F | 62°F | 36% | 19% |
| August 8 | 82°F | 61°F | 38% | 20% |
| August 15 | 81°F | 60°F | 39% | 20% |
| August 22 | 80°F | 58°F | 39% | 20% |
| August 31 | 79°F | 56°F | 37% | 19% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 83°F | 62°F | 36% | 19% | 14 h 30 min |
| August 2 | 82°F | 62°F | 36% | 19% | 14 h 30 min |
| August 3 | 82°F | 62°F | 37% | 19% | 14 h 20 min |
| August 4 | 82°F | 62°F | 37% | 20% | 14 h 20 min |
| August 5 | 82°F | 62°F | 37% | 20% | 14 h 20 min |
| August 6 | 82°F | 61°F | 37% | 20% | 14 h 20 min |
| August 7 | 82°F | 61°F | 38% | 20% | 14 h 20 min |
| August 8 | 82°F | 61°F | 38% | 20% | 14 h 10 min |
| August 9 | 82°F | 61°F | 38% | 20% | 14 h 10 min |
| August 10 | 82°F | 61°F | 38% | 20% | 14 h 10 min |
| August 11 | 82°F | 61°F | 38% | 20% | 14 h 10 min |
| August 12 | 82°F | 61°F | 39% | 20% | 14 h |
| August 13 | 81°F | 60°F | 39% | 20% | 14 h |
| August 14 | 81°F | 60°F | 39% | 20% | 14 h |
| August 15 | 81°F | 60°F | 39% | 20% | 14 h |
| August 16 | 81°F | 60°F | 39% | 20% | 13 h 50 min |
| August 17 | 81°F | 60°F | 39% | 20% | 13 h 50 min |
| August 18 | 81°F | 59°F | 39% | 20% | 13 h 50 min |
| August 19 | 81°F | 59°F | 39% | 20% | 13 h 50 min |
| August 20 | 81°F | 59°F | 39% | 20% | 13 h 40 min |
| August 21 | 81°F | 59°F | 39% | 20% | 13 h 40 min |
| August 22 | 80°F | 58°F | 39% | 20% | 13 h 40 min |
| August 23 | 80°F | 58°F | 39% | 20% | 13 h 40 min |
| August 24 | 80°F | 58°F | 39% | 20% | 13 h 30 min |
| August 25 | 80°F | 58°F | 38% | 20% | 13 h 30 min |
| August 26 | 80°F | 57°F | 38% | 19% | 13 h 30 min |
| August 27 | 80°F | 57°F | 38% | 19% | 13 h 30 min |
| August 28 | 80°F | 57°F | 38% | 19% | 13 h 20 min |
| August 29 | 79°F | 57°F | 38% | 19% | 13 h 20 min |
| August 30 | 79°F | 56°F | 37% | 19% | 13 h 20 min |
| August 31 | 79°F | 56°F | 37% | 19% | 13 h 10 min |
- Normal high
- 81°FAugust average
- Normal low
- 60°FAugust average
- Precipitation
- 3.88 inmonth total
- Days with precipitation
- 120.01 inch or more
- Days at 90°F or more
- 3
- Daylight
- 14 h 30 min to 13 h 10 minAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 19
- Sunshine
- 80%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00094988; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Marshalltown in August?
On a given August day the chance of 0.01 inch or more is 38% on average, highest around August 17 (39%). In all, 3.88 in falls on 12 days of a normal August, 1 of them with an inch or more.
In a normal August in Marshalltown, 3 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00094988.
What are the records for August in Marshalltown?
The warmest August temperature on this station's record (since 1996) is 100°F, on August 23, 2023; the coldest is 41°F, on August 31, 2009. The wettest August brought 9.24 in (2010).
The August mean against the 1991-2020 normal of 70.2°F: 2021 72.5°F (+2.3), 2022 71.8°F (+1.6), 2023 73.2°F (+3.0), 2024 71.8°F (+1.6), 2025 70.5°F (+0.3), 2026 72.0°F (+1.8). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 72.5°F | +2.3°F | 3.56 in |
| 2022 | 71.8°F | +1.6°F | 3.33 in |
| 2023 | 73.2°F | +3.0°F | 1.17 in |
| 2024 | 71.8°F | +1.6°F | 1.58 in |
| 2025 | 70.5°F | +0.3°F | 3.00 in |
| 2026 | 72.0°F | +1.8°F | 3.40 in |
Source: records: ACIS, station USW00094988; recent months: ACIS, station USW00094988. Records and recent months use complete months only.
How does August in Marshalltown compare across Iowa?
Across the 132 places PlainClimate covers in Iowa, August normal highs run from 76°F in Northwood to 85°F in Donnellson; Marshalltown's is 81°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.