September weather forecastSumner, OK
September
Weather in September
September, the first month of the autumn in Sumner, is still a warm month, with an average temperature ranging between max 84.4°F (29.1°C) and min 64.9°F (18.3°C).Temperature
The beginning of September subtly marks a decrease in the average high-temperature, transitioning from a hot 92.8°F (33.8°C) in August to a warm 84.4°F (29.1°C). In Sumner, in September, the average low-temperature is an enjoyable 64.9°F (18.3°C).Heat index
For most parts of September, the heat index is evaluated at a tropical 89.6°F (32°C). Continuous exposure and activity could induce a sense of tiredness and subsequently, heat cramps.One should consider that heat index numbers are for shaded settings and light wind. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', ties air temperature with relative humidity to produce the perceived temperature sensation. An individual's temperature experience can be influenced by extra factors, including metabolic differences, activity levels, and clothing. By being directly under the sun, it's possible for the felt temperature to increase by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.
Humidity
The average relative humidity in September is 65%.Rainfall
In Sumner, in September, during 12.1 rainfall days, 2.52" (64mm) of precipitation is typically accumulated. Throughout the year, there are 119.3 rainfall days, and 23.27" (591mm) of precipitation is accumulated.Snowfall
In Sumner, snow does not fall in April through October.Daylight
In Sumner, the average length of the day in September is 12h and 24min.On the first day of the month, sunrise is at 7:00 am and sunset at 7:55 pm. On the last day of September, sunrise is at 7:23 am and sunset at 7:12 pm CDT.
Sunshine
In Sumner, the average sunshine in September is 8.7h.UV index
In Sumner, Oklahoma, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: A maximum UV index of 5 in September translates into the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sumner, OK
- Average high temperature in September: 84.4°F
The warmest month (with the highest average high temperature) is July (93.9°F).
The month with the lowest average high temperature is January (46.9°F).
- Average low temperature in September: 64.9°F
The month with the highest average low temperature is July (73.4°F).
The coldest month (with the lowest average low temperature) is January (30.2°F).
Average pressure in September
Sumner, OK
- Average pressure in September: 29.98"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
Sumner, OK
- Average wind speed in September: 8.7mph
The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Sumner, OK
- Average humidity in September: 65%
The month with the highest relative humidity is May (74%).
The month with the lowest relative humidity is August (61%).
Average rainfall in September
Sumner, OK
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.21").
The driest month (with the least rainfall) is December (0.83").
Average rainfall days in September
Sumner, OK
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is May (14.5 days).
The month with the least rainy days is January (4.2 days).
Average snowfall in September
Sumner, OK
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.38").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Sumner, OK
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Sumner, OK
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is August (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 6h and 6min).
Average sunshine days in September
Sumner, OK
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is December (23.4 days).
The month with the least sunshine days is May (13.9 days).
Average UV index in September
Sumner, OK
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
Sumner, OK
- Average cloud cover in September: 25
The month with the most cloud cover is March (Cloud cover 37).
The months with the least cloud cover are June and August (Cloud cover 19).
Average visibility in September
Sumner, OK
- 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).





