Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The transition from August to September sees average high-temperatures adjusting to a still warm 74.1°F (23.4°C), from a not significantly different 79.2°F (26.2°C). In the month of September, Knierim witnesses a consistent average low-temperature of 54.9°F (12.7°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In September, the rain falls for 8.8 days. Throughout September, 0.79" (20mm) of precipitation is accumulated. Throughout the year, there are 84.6 rainfall days, and 7.91" (201mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:43 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:14 am and sunset at 7:00 pm CDT.
Sunshine
In September, the average sunshine in Knierim is 9h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average UV index of 5 in September transforms into this advice:
Take precautions - Protection against sunburn is recommended. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Knierim have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September in Knierim?
Average temperature in September
Knierim, IA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (25°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).
Average pressure in September
Knierim, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Knierim, IA
- Average wind speed in September: 8.5mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in September
Knierim, IA
- Average humidity in September: 75%
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are April and October (68%).
Average rainfall in September
Knierim, IA
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (1.34").
The driest month (with the least rainfall) is January (0.24").
Average rainfall days in September
Knierim, IA
- Average rainfall days in September: 8.8 days
The month with the highest number of rainy days is June (12 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in September
Knierim, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Knierim, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Knierim, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Knierim, IA
- Average sunshine days in September: 19.1 days
The month with the most sunshine days is December (24.3 days).
The month with the least sunshine days is June (15.5 days).
Average UV index in September
Knierim, IA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and February (UV index 1).
Average cloud cover in September
Knierim, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are July and September (Cloud cover 31).
Average visibility in September
Knierim, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Knierim, Iowa, USA
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