Mason City weather in August: Mason City, Iowa: normal highs, lows, rain and records for August
Mason City in August has a normal high of 80°F and a normal low of 58°F, a daily mean of 69°F, falling from 82°F on the 1st to 79°F by the 31st. Measurable precipitation falls on 9 days in a normal August, 3.79 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 14°C, 96 mm of precipitation in August.
- NOAA stationMason City Municipal Airport
- Station IDUSW00014940
- Location43.15°N 93.33°W
- Elevation1,225 ft (373 m)
- From the center6 miles
- Population26,948
- Jan 24° 7°
- Feb 29° 11°
- Mar 42° 24°
- Apr 58° 35°
- May 70° 47°
- Jun 80° 57°
- Jul 83° 61°
- Aug 80° 58°
- Sep 74° 49°
- Oct 60° 37°
- Nov 44° 24°
- Dec 30° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Mason City in August?
The normal high is 80°F and the normal low 58°F, for a daily mean of 68.9°F. August is 2.6°F cooler than July and 7.5°F warmer than September. August is the 2nd warmest month of the year in Mason City and the 5th wettest. Across the month the normal high falls 3°F, from 82°F on August 1 to 79°F on August 31. From one year to the next August's mean temperature typically moves about 2.4°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 67°F and 71°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 31%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 82°F | 60°F | 31% | 20% |
| August 8 | 81°F | 59°F | 31% | 19% |
| August 15 | 80°F | 58°F | 30% | 19% |
| August 22 | 80°F | 57°F | 29% | 19% |
| August 31 | 79°F | 54°F | 29% | 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 | 82°F | 60°F | 31% | 20% | 14 h 30 min |
| August 2 | 81°F | 60°F | 31% | 20% | 14 h 30 min |
| August 3 | 81°F | 60°F | 31% | 20% | 14 h 30 min |
| August 4 | 81°F | 60°F | 31% | 20% | 14 h 30 min |
| August 5 | 81°F | 59°F | 31% | 20% | 14 h 20 min |
| August 6 | 81°F | 59°F | 31% | 20% | 14 h 20 min |
| August 7 | 81°F | 59°F | 31% | 20% | 14 h 20 min |
| August 8 | 81°F | 59°F | 31% | 19% | 14 h 20 min |
| August 9 | 81°F | 59°F | 31% | 19% | 14 h 20 min |
| August 10 | 81°F | 59°F | 31% | 19% | 14 h 10 min |
| August 11 | 81°F | 59°F | 30% | 19% | 14 h 10 min |
| August 12 | 81°F | 59°F | 30% | 19% | 14 h 10 min |
| August 13 | 81°F | 58°F | 30% | 19% | 14 h 10 min |
| August 14 | 81°F | 58°F | 30% | 19% | 14 h |
| August 15 | 80°F | 58°F | 30% | 19% | 14 h |
| August 16 | 80°F | 58°F | 30% | 19% | 14 h |
| August 17 | 80°F | 58°F | 30% | 19% | 14 h |
| August 18 | 80°F | 58°F | 30% | 19% | 13 h 50 min |
| August 19 | 80°F | 57°F | 30% | 19% | 13 h 50 min |
| August 20 | 80°F | 57°F | 30% | 19% | 13 h 50 min |
| August 21 | 80°F | 57°F | 30% | 19% | 13 h 40 min |
| August 22 | 80°F | 57°F | 29% | 19% | 13 h 40 min |
| August 23 | 80°F | 57°F | 29% | 19% | 13 h 40 min |
| August 24 | 80°F | 56°F | 29% | 19% | 13 h 40 min |
| August 25 | 79°F | 56°F | 29% | 19% | 13 h 30 min |
| August 26 | 79°F | 56°F | 29% | 19% | 13 h 30 min |
| August 27 | 79°F | 56°F | 29% | 19% | 13 h 30 min |
| August 28 | 79°F | 55°F | 29% | 19% | 13 h 30 min |
| August 29 | 79°F | 55°F | 29% | 19% | 13 h 20 min |
| August 30 | 79°F | 55°F | 29% | 19% | 13 h 20 min |
| August 31 | 79°F | 54°F | 29% | 19% | 13 h 20 min |
- Normal high
- 80°FAugust average
- Normal low
- 58°FAugust average
- Precipitation
- 3.79 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 2
- Daylight
- 14 h 30 min to 13 h 20 minAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 18
- Sunshine
- 80%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014940; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Mason City in August?
On a given August day the chance of 0.01 inch or more is 30% on average, highest around August 1 (31%). In all, 3.79 in falls on 9 days of a normal August, 1 of them with an inch or more.
In a normal August in Mason City, 2 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014940.
How humid and windy is Mason City in August?
At 3 p.m. the normal temperature is 78°F with 55% relative humidity and a dew point of 60°F; at 6 a.m. it is 59°F with 92% humidity. The wind averages 8.1 mph, most often from the south-southwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 59°F | 57°F | 92% | 6.0 mph | 64% |
| 9 a.m. | 69°F | 61°F | 74% | 9.6 mph | 66% |
| noon | 76°F | 61°F | 59% | 11.1 mph | 62% |
| 3 p.m. | 78°F | 60°F | 55% | 11.3 mph | 64% |
| 6 p.m. | 74°F | 62°F | 66% | 7.9 mph | 74% |
| 9 p.m. | 64°F | 60°F | 87% | 6.2 mph | 75% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014940. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in Mason City?
The warmest August temperature on this station's record (since 1948) is 101°F, on August 13, 1965; the coldest is 35°F, on August 20, 1950. The wettest August brought 15.76 in (1980).
The August mean against the 1991-2020 normal of 68.9°F: 2021 70.1°F (+1.2), 2022 69.6°F (+0.7), 2023 71.7°F (+2.8), 2024 69.3°F (+0.4), 2025 68.9°F (at normal), 2026 70.0°F (+1.1). 5 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.1°F | +1.2°F | 7.77 in |
| 2022 | 69.6°F | +0.7°F | 7.12 in |
| 2023 | 71.7°F | +2.8°F | 2.11 in |
| 2024 | 69.3°F | +0.4°F | 1.59 in |
| 2025 | 68.9°F | at normal | 4.17 in |
| 2026 | 70.0°F | +1.1°F | 2.55 in |
Source: records: ACIS, station USW00014940; recent months: ACIS, station USW00014940. Records and recent months use complete months only.
How does August in Mason City 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; Mason City's is 80°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.