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
September ushers in a minute temperature change, with average high-temperatures reducing from August's moderately hot 78.4°F (25.8°C) to a pleasant 72°F (22.2°C). An average nighttime temperature of 53.2°F (11.8°C) is noted during the month of September.Humidity
In September, the average relative humidity is 80%.Rainfall
In O'Neill, during September, the rain falls for 12.5 days and regularly aggregates up to 2.56" (65mm) of precipitation. In O'Neill, during the entire year, the rain falls for 139.6 days and collects up to 24.92" (633mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:37 pm. On the last day of September, sunrise is at 7:00 am and sunset at 6:46 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In O'Neill, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Act with care - The suggestion to avoid sunburn is emphasized. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Boost your sun resistance with garments that are densely woven yet spacious.
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 O'Neill have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does O'Neill have in September?
How high is the UV index in September?
Average temperature in September
O'Neill, IA
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (11.7°F).
Average pressure in September
O'Neill, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
O'Neill, IA
- Average wind speed in September: 7.9mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
O'Neill, IA
- Average humidity in September: 80%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
O'Neill, IA
- Average rainfall in September: 2.56"
The wettest months (with the highest rainfall) are May and June (3.54").
The driest month (with the least rainfall) is December (0.98").
Average rainfall days in September
O'Neill, IA
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.1 days).
Average snowfall in September
O'Neill, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.29").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
O'Neill, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
O'Neill, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
O'Neill, IA
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is May (9.4 days).
Average UV index in September
O'Neill, IA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
O'Neill, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
O'Neill, IA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
O'Neill, Iowa, USA
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