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 arrival of September is marked by an average high-temperature of a still warm 74.5°F (23.6°C), bearing a close resemblance to August. In Defiance, the expected average low-temperature for September is a moderate 55.6°F (13.1°C).Humidity
The average relative humidity in September is 75%.Rainfall
In Defiance, in September, during 11.8 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. In Defiance, during the entire year, the rain falls for 123 days and collects up to 24.72" (628mm) of precipitation.Snowfall
June through September are months without snowfall in Defiance.Daylight
In September, the average length of the day 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 Defiance is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Defiance have in September?
What is the UV index intensity in September?
Average temperature in September
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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
Defiance, 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).
Defiance, Iowa, USA
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