Sioux Falls weather in August: Sioux Falls, South Dakota: normal highs, lows, rain and records for August
Sioux Falls in August has a normal high of 83°F and a normal low of 61°F, a daily mean of 72°F, falling from 85°F on the 1st to 80°F by the 31st. Measurable precipitation falls on 9 days in a normal August, 3.34 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 28°C and low of 16°C, 85 mm of precipitation in August.
- NOAA stationSioux Falls Foss Field
- Station IDUSW00014944
- Location43.59°N 96.73°W
- Elevation1,430 ft (436 m)
- From the center3 miles
- Population209,289
- Jan 27° 9°
- Feb 32° 13°
- Mar 45° 24°
- Apr 59° 36°
- May 71° 48°
- Jun 81° 59°
- Jul 85° 63°
- Aug 83° 61°
- Sep 76° 52°
- Oct 61° 38°
- Nov 45° 25°
- Dec 32° 13°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Sioux Falls in August?
The normal high is 83°F and the normal low 61°F, for a daily mean of 72.0°F. August is 2.4°F cooler than July and 8.2°F warmer than September. August is the 2nd warmest month of the year in Sioux Falls and the 3rd wettest. Across the month the normal high falls 5°F, from 85°F on August 1 to 80°F on August 31. From one year to the next August's mean temperature typically moves about 2.3°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 70°F and 74°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 | 85°F | 63°F | 31% | 17% |
| August 8 | 84°F | 63°F | 30% | 17% |
| August 15 | 83°F | 62°F | 30% | 17% |
| August 22 | 82°F | 60°F | 29% | 17% |
| August 31 | 80°F | 58°F | 28% | 16% |
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 | 85°F | 63°F | 31% | 17% | 14 h 40 min |
| August 2 | 85°F | 63°F | 31% | 17% | 14 h 30 min |
| August 3 | 85°F | 63°F | 31% | 17% | 14 h 30 min |
| August 4 | 85°F | 63°F | 31% | 17% | 14 h 30 min |
| August 5 | 84°F | 63°F | 31% | 17% | 14 h 30 min |
| August 6 | 84°F | 63°F | 31% | 17% | 14 h 20 min |
| August 7 | 84°F | 63°F | 31% | 17% | 14 h 20 min |
| August 8 | 84°F | 63°F | 30% | 17% | 14 h 20 min |
| August 9 | 84°F | 63°F | 30% | 17% | 14 h 20 min |
| August 10 | 84°F | 62°F | 30% | 17% | 14 h 10 min |
| August 11 | 84°F | 62°F | 30% | 17% | 14 h 10 min |
| August 12 | 84°F | 62°F | 30% | 17% | 14 h 10 min |
| August 13 | 83°F | 62°F | 30% | 17% | 14 h 10 min |
| August 14 | 83°F | 62°F | 30% | 17% | 14 h |
| August 15 | 83°F | 62°F | 30% | 17% | 14 h |
| August 16 | 83°F | 61°F | 30% | 17% | 14 h |
| August 17 | 83°F | 61°F | 30% | 17% | 14 h |
| August 18 | 83°F | 61°F | 30% | 17% | 13 h 50 min |
| August 19 | 83°F | 61°F | 30% | 17% | 13 h 50 min |
| August 20 | 82°F | 61°F | 29% | 17% | 13 h 50 min |
| August 21 | 82°F | 60°F | 29% | 17% | 13 h 50 min |
| August 22 | 82°F | 60°F | 29% | 17% | 13 h 40 min |
| August 23 | 82°F | 60°F | 29% | 17% | 13 h 40 min |
| August 24 | 82°F | 60°F | 29% | 17% | 13 h 40 min |
| August 25 | 81°F | 60°F | 29% | 17% | 13 h 40 min |
| August 26 | 81°F | 59°F | 29% | 16% | 13 h 30 min |
| August 27 | 81°F | 59°F | 29% | 16% | 13 h 30 min |
| August 28 | 81°F | 59°F | 29% | 16% | 13 h 30 min |
| August 29 | 81°F | 58°F | 29% | 16% | 13 h 20 min |
| August 30 | 81°F | 58°F | 28% | 16% | 13 h 20 min |
| August 31 | 80°F | 58°F | 28% | 16% | 13 h 20 min |
- Normal high
- 83°FAugust average
- Normal low
- 61°FAugust average
- Precipitation
- 3.34 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 4
- Daylight
- 14 h 40 min to 13 h 20 minAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 20
- Sunshine
- 81%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014944; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Sioux Falls in August?
On a given August day the chance of 0.01 inch or more is 30% on average, highest around August 3 (31%). In all, 3.34 in falls on 9 days of a normal August, 1 of them with an inch or more.
In a normal August in Sioux Falls, 4 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014944.
How humid and windy is Sioux Falls in August?
At 3 p.m. the normal temperature is 79°F with 52% relative humidity and a dew point of 60°F; at 6 a.m. it is 61°F with 88% humidity. The wind averages 9.2 mph, most often from the south in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 61°F | 57°F | 88% | 6.7 mph | 60% |
| 9 a.m. | 69°F | 60°F | 73% | 9.8 mph | 67% |
| noon | 76°F | 60°F | 57% | 11.8 mph | 57% |
| 3 p.m. | 79°F | 60°F | 52% | 12.2 mph | 64% |
| 6 p.m. | 76°F | 60°F | 58% | 10.5 mph | 63% |
| 9 p.m. | 68°F | 60°F | 76% | 8.1 mph | 75% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014944. 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 Sioux Falls?
The warmest August temperature on Sioux Falls's official record (since 1893) is 109°F, on August 24, 1936; the coldest is 34°F, on August 29, 1893. The wettest August brought 9.33 in (1932).
The August mean against the 1991-2020 normal of 72.0°F: 2021 74.4°F (+2.4), 2022 73.6°F (+1.6), 2023 75.5°F (+3.5), 2024 71.6°F (−0.4), 2025 71.1°F (−0.9), 2026 73.6°F (+1.6). 4 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 74.4°F | +2.4°F | 6.29 in |
| 2022 | 73.6°F | +1.6°F | 6.88 in |
| 2023 | 75.5°F | +3.5°F | 4.54 in |
| 2024 | 71.6°F | −0.4°F | 2.19 in |
| 2025 | 71.1°F | −0.9°F | 2.81 in |
| 2026 | 73.6°F | +1.6°F | 1.21 in |
Source: records: ACIS, NWS threaded record FSDthr; recent months: ACIS, station USW00014944. Records and recent months use complete months only.
How does August in Sioux Falls compare across South Dakota?
Across the 100 places PlainClimate covers in South Dakota, August normal highs run from 78°F in Astoria to 91°F in Interior; Sioux Falls's is 83°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Sioux Falls in July85°F by day, 63°F at night
- Sioux Falls in September76°F by day, 52°F at night
- Sioux Falls through the yearEvery month, frost dates, records and recent years
- South Dakota in AugustThe statewide normal and the warmest and coolest places
- Interior: South Dakota's warmest Augustnormal high 91°F