Sioux City weather in September 2025

The temperatures in Sioux City in September are comfortable with low of 14°C and and high up to 25°C.

You can expect about 3 to 8 days of rain in Sioux City during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.

Our weather forecast can give you a great sense of what weather to expect in Sioux City in September 2025.

If you’re planning to visit Sioux City in the near future, we highly recommend that you review the 14 day weather forecast for Sioux City before you arrive.

Temperatures

25° / 14°

Rainy Days

Snowy Days

Dry Days

Rainfall

Sun Hours

8.2

Hrs

Sun	Mon	Tue	Wed	Thu	Fri	Sat
	1 36° /15°	2 38° /15°	3 35° /14°	4 37° /14°	5 33° /17°	6 32° /14°
7 34° /10°	8 37° /15°	9 32° /15°	10 27° /15°	11 31° /14°	12 31° /12°	13 33° /13°
14 34° /13°	15 32° /19°	16 31° /15°	17 30° /13°	18 34° /14°	19 36° /17°	20 34° /16°
21 27° /14°	22 23° /13°	23 24° /10°	24 28° /9°	25 29° /11°	26 26° /9°	27 26° /10°
28 30° /9°	29 32° /12°	30 31° /14°

Explore the weather in Sioux City in other months

Sioux City annual weather

Month	Temperatures	Rainy Days	Dry Days	Snowy Days	Rainfall	Weather	More details
January	-2° / -10°	6	22	3	23 mm	Awful	Sioux City in January
February	0° / -9°	6	19	3	26 mm	Awful	Sioux City in February
March	9° / -1°	6	23	2	52 mm	Bad	Sioux City in March
April	15° / 5°	7	22	1	97 mm	Ok	Sioux City in April
May	21° / 11°	9	22	0	133 mm	Ok	Sioux City in May
June	27° / 17°	8	22	0	143 mm	Good	Sioux City in June
July	30° / 19°	6	25	0	80 mm	Good	Sioux City in July
August	29° / 17°	7	24	0	123 mm	Ok	Sioux City in August
September	25° / 14°	5	25	0	77 mm	Perfect	Sioux City in September
October	17° / 7°	5	25	0	64 mm	Good	Sioux City in October
November	9° / 0°	4	25	1	33 mm	Ok	Sioux City in November
December	1° / -7°	6	22	3	41 mm	Awful	Sioux City in December

Temperatures in Sioux City in September

Rain in Sioux City in September

Weather in Sioux City in September - FAQ

What is the average temperature in Sioux City in September?

The average temperature in Sioux City in September is 14/25° C.

What is the chance of rain in Sioux City in September?

On average, there are 5 rainy days in Sioux City during September.

Weather wise, is September a good time to visit Sioux City?

The weather in Sioux City in September is perfect.

Can it snow in Sioux City in September?

On average, there are 0 snowy days in Sioux City in September.

More about the weather in Sioux City