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
Diagonal observes a small decrease in the average high-temperature with the arrival of September, falling from August's 81.7°F (27.6°C) to a still warm 75.9°F (24.4°C). September nights are marked by an average low-temperature of 56.3°F (13.5°C).Humidity
In Diagonal, the average relative humidity in September is 76%.Rainfall
In Diagonal, in September, during 11 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. In Diagonal, during the entire year, the rain falls for 126.9 days and collects up to 22.6" (574mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 27min.On the first day of September, sunrise is at 6:45 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 7:00 pm CDT.
Sunshine
The average sunshine in September in Diagonal is 9.3h.UV index
In Diagonal, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 5 during September translates into the following directions:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Frequently asked questions
What are the temperatures in Diagonal in September?
What is the average humidity in September in Diagonal?
How much does it rain in Diagonal in September?
When it does not snow in Diagonal?
Does it snow in Diagonal in September?
How many hours of daylight does Diagonal have in September?
What time are sunrise and sunset in September in Diagonal?
How many hours of sunshine does Diagonal have in September?
How high is the UV index in September in Diagonal?
Average temperature in September
Diagonal, IA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in September
Diagonal, 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
Diagonal, IA
- Average wind speed in September: 7.8mph
The windiest months (with the highest average wind speed) are January, February and March (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Diagonal, IA
- Average humidity in September: 76%
The month with the highest relative humidity is June (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Diagonal, IA
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is June (3.86").
The driest months (with the least rainfall) are February and December (0.71").
Average rainfall days in September
Diagonal, IA
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Diagonal, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Diagonal, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Diagonal, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 2min
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 36min).
Average sunshine days in September
Diagonal, IA
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is May (10.6 days).
Average UV index in September
Diagonal, IA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Diagonal, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Diagonal, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Diagonal, Iowa, USA
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