September weather forecastHeyburn, OK
September
Weather in September
September, the first month of the autumn in Heyburn, is also a moderately hot month, with an average temperature ranging between min 64.2°F (17.9°C) and max 83.7°F (28.7°C).Temperature
Transitioning from August to September involves a subtle drop in average high-temperatures, descending from a hot 90.9°F (32.7°C) to a moderately hot 83.7°F (28.7°C). September nights cool down to an average low-temperature of 64.2°F (17.9°C).Heat index
September's heat index is computed to be a tropical 89.6°F (32°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.The standards for the heat index are set for locations in shade and under light breezes. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', is a measure of how hot it feels when the actual air humidity is factored in. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.
Humidity
In September, the average relative humidity is 69%.Rainfall
In September, the rain falls for 11.5 days. Throughout September, 3.35" (85mm) of precipitation is accumulated. In Heyburn, Oklahoma, during the entire year, the rain falls for 129.3 days and collects up to 29.13" (740mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Heyburn, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 6:57 am and sunset at 7:52 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 7:09 pm CDT.
Sunshine
In Heyburn, the average sunshine in September is 8.6h.UV index
The average daily maximum UV index in September is 5. 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 maximum daily UV index of 5 during September translates into the following directions:
Guard yourself - Avoiding sunburn is suggested. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Heyburn, OK
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is July (91.4°F).
The month with the lowest average high temperature is January (46.9°F).
- Average low temperature in September: 64.2°F
The month with the highest average low temperature is July (72.1°F).
The coldest month (with the lowest average low temperature) is January (31.5°F).
Average pressure in September
Heyburn, 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 (29.89"Hg).
Average wind speed in September
Heyburn, OK
- Average wind speed in September: 7.6mph
The windiest months (with the highest average wind speed) are March and April (10.9mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in September
Heyburn, OK
- Average humidity in September: 69%
The month with the highest relative humidity is May (80%).
The months with the lowest relative humidity are January and August (66%).
Average rainfall in September
Heyburn, OK
- Average rainfall in September: 3.35"
The wettest month (with the highest rainfall) is May (4.92").
The driest month (with the least rainfall) is January (1.22").
Average rainfall days in September
Heyburn, OK
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (16.4 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in September
Heyburn, OK
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.65").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Heyburn, OK
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.4 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
Heyburn, 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 48min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Heyburn, OK
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is January (22.5 days).
The month with the least sunshine days is May (12.7 days).
Average UV index in September
Heyburn, OK
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Heyburn, OK
- Average cloud cover in September: 28
The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 21).
Average visibility in September
Heyburn, 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).





