September weather forecastHelena, OK
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Helena, Oklahoma, with an average temperature fluctuating between 66.4°F (19.1°C) and 84.9°F (29.4°C).Temperature
September's arrival comes with a mild decrease in the average high-temperature, moving subtly from a hot 93°F (33.9°C) in August to a moderately hot 84.9°F (29.4°C). Helena cools down to an average low-temperature of 66.4°F (19.1°C) throughout the month of September.Heat index
The heat index value for September is appraised at a tropical 89.6°F (32°C). Constant activity during exposure could result in a state of weariness and possibly heat cramps.Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', represents the fusion of temperature and moisture in the air to suggest how warm it feels. The influence of weather is personal, with varied individuals experiencing it differently due to differences in body mass, stature, and physical exertion levels. Consider the fact that direct sun exposure can influence how hot one feels, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
In September, the average relative humidity is 60%.Rainfall
In Helena, Oklahoma, during September, the rain falls for 11.8 days and regularly aggregates up to 1.61" (41mm) of precipitation. In Helena, during the entire year, the rain falls for 103.1 days and collects up to 18.11" (460mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 24min.On the first day of the month, sunrise is at 7:04 am and sunset at 8:00 pm. On the last day of September, sunrise is at 7:28 am and sunset at 7:17 pm CDT.
Sunshine
In Helena, Oklahoma, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 6 translates into these guidelines:
Elude overexposure. Fair-skinned people could get burnt in less than 20 minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Helena, OK
- Average high temperature in September: 84.9°F
The warmest month (with the highest average high temperature) is July (95.2°F).
The month with the lowest average high temperature is January (46.4°F).
- Average low temperature in September: 66.4°F
The month with the highest average low temperature is July (75.2°F).
The coldest month (with the lowest average low temperature) is January (29.7°F).
Average pressure in September
Helena, 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 (29.86"Hg).
Average wind speed in September
Helena, OK
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is April (11.8mph).
The calmest month (with the lowest average wind speed) is August (8.8mph).
Average humidity in September
Helena, OK
- Average humidity in September: 60%
The month with the highest relative humidity is May (66%).
The month with the lowest relative humidity is July (54%).
Average rainfall in September
Helena, OK
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is February (0.51").
Average rainfall days in September
Helena, OK
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is December (3.6 days).
Average snowfall in September
Helena, OK
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.46").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Helena, OK
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Helena, 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: 9h and 0min
The month with the most sunshine is June (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Helena, OK
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is January (25.5 days).
The month with the least sunshine days is May (15 days).
Average UV index in September
Helena, OK
- Average UV index in September: 6
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
Helena, OK
- Average cloud cover in September: 23
The months with the most cloud cover are March and April (Cloud cover 33).
The month with the least cloud cover is June (Cloud cover 17).
Average visibility in September
Helena, 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).
