Sioux City in September
8.1out of 10
Yes, a good time to go
Warm and comfortable: highs around 25°C. Some rain: about 8 rainy days.
25°CAvg high
13°CAvg low
8Rainy days (76 mm)
12:16 hDaylight
07:12Sunrise · 19:28 Sunset
Why this score
- Warm and comfortable: highs around 25°C
- Some rain: about 8 rainy days
What to wear and pack
- T-shirts and light layers
- A light jacket for cooler evenings
How reliable is the forecast?
Rainfall in September is fairly consistent from year to year (2.6 days). Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | -1°C | -10°C | 23 mm | 5 | – | – | 4.4 |
| February | 2°C | -8°C | 27 mm | 5 | – | – | 4.5 |
| March | 9°C | -2°C | 55 mm | 7 | – | – | 5.8 |
| April | 17°C | 4°C | 100 mm | 11 | – | – | 6.7 |
| May | 22°C | 11°C | 126 mm | 13 | – | – | 7.2 |
| June | 28°C | 17°C | 123 mm | 12 | – | – | 7.3 |
| July | 30°C | 19°C | 76 mm | 9 | – | – | 7.7 |
| August | 28°C | 17°C | 98 mm | 9 | – | – | 7.8 |
| September | 25°C | 13°C | 76 mm | 8 | – | – | 8.1 |
| October | 17°C | 6°C | 61 mm | 7 | – | – | 7.4 |
| November | 9°C | -2°C | 40 mm | 6 | – | – | 5.9 |
| December | 1°C | -8°C | 30 mm | 5 | – | – | 4.4 |
Frequently asked questions
How hot is Sioux City in September?
Daytime highs average 25°C and nights about 13°C.
When is the best time to visit Sioux City?
The best months are September, August, July.