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
Denison registers an average high-temperature of a still warm 74.5°F (23.6°C) with the arrival of September, showing minor deviation from the preceding month. Denison experiences a nighttime temperature average of 55.6°F (13.1°C) during September.Humidity
In Denison, the average relative humidity in September is 75%.Rainfall
In Denison, during September, the rain falls for 11.8 days and regularly aggregates up to 2.64" (67mm) of precipitation. In Denison, during the entire year, the rain falls for 123 days and collects up to 24.72" (628mm) of precipitation.Snowfall
In Denison, snow does not fall in June through September.Daylight
The average length of the day in September in Denison is 12h and 28min.On the first day of the month, sunrise is at 6:47 am and sunset at 7:54 pm. On the last day of September, sunrise is at 7:18 am and sunset at 7:04 pm CDT.
Sunshine
The average sunshine in September in Denison is 9h.UV index
The average daily maximum UV index in September in Denison is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Prioritize safety - Recommendations to avert sunburn are shared. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Denison?
What is the average humidity in September in Denison?
How much does it rain in Denison in September?
When it does not snow in Denison?
Does it snow in Denison in September?
What is the average length of the day in September in Denison?
When is the sunrise / sunset in September in Denison?
How many hours of sunshine does Denison have in September?
What is the UV index intensity in September in Denison?
Average temperature in September
Denison, IA
- Average high temperature in September: 74.5°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (27°F).
- Average low temperature in September: 55.6°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (14°F).
Average pressure in September
Denison, IA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Denison, IA
- Average wind speed in September: 8.7mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.4mph).
Average humidity in September
Denison, IA
- Average humidity in September: 75%
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are April and October (68%).
Average rainfall in September
Denison, IA
- Average rainfall in September: 2.64"
The wettest month (with the highest rainfall) is May (3.82").
The driest month (with the least rainfall) is January (0.71").
Average rainfall days in September
Denison, IA
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is June (16.5 days).
The month with the least rainy days is February (3 days).
Average snowfall in September
Denison, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Denison, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Denison, 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 12min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Denison, IA
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is June (11.9 days).
Average UV index in September
Denison, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Denison, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Denison, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Denison, Iowa, USA
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