September weather forecastAltus, OK
September
Weather in September
The weather slightly eases off in Altus come September, with a high of 86.7°F (30.4°C). Signals of autumn's arrival become more apparent, as the lush greenery begins to transition into a myriad of warm colors. Reminiscent of the heat of summer, the afternoon sun still manages to warm the day quite generously. The streets start getting quieter, with the song of crickets providing a soft end-of-summer melody. The stars seem to twinkle more brightly, witch the cool nights becoming noticeably longer.Temperature
The start of September signals a decrease in the average high-temperature, transitioning from a sweltering 95.7°F (35.4°C) in August to a hot 86.7°F (30.4°C). In the month of September, the average low-temperature usually rests at a comfortable 67.8°F (19.9°C).Heat index
In September, the average heat index is calculated to be a hot 91.4°F (33°C). Implement enhanced safety actions, heat cramps and heat exhaustion could occur. Sustained activity might result in heatstroke.It is important to note that the heat index values are for shaded areas and light wind scenarios. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is an estimation of the warmth sensation when considering humidity levels. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Kids often lack the knowledge about the necessity to take breaks and consume liquids. Thirst, as a late symptom of dehydration, necessitates the maintenance of hydration, particularly during enduring physical activities.
Humidity
The average relative humidity in September is 58%.Rainfall
In Altus, during September, the rain falls for 12.3 days and regularly aggregates up to 2.09" (53mm) of precipitation. In Altus, during the entire year, the rain falls for 104.5 days and collects up to 20.59" (523mm) of precipitation.Snowfall
May through October are months without snowfall in Altus.Daylight
The average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 7:10 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:22 pm CDT.
Sunshine
In Altus, the average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 6 during September leads to these advisories:
Shun overexposure. Protection from sun ravages is indispensable. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Altus, OK
- Average high temperature in September: 86.7°F
The warmest month (with the highest average high temperature) is July (96.4°F).
The month with the lowest average high temperature is December (51.6°F).
- Average low temperature in September: 67.8°F
The month with the highest average low temperature is July (76.3°F).
The coldest month (with the lowest average low temperature) is January (33.4°F).
Average pressure in September
Altus, OK
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Altus, OK
- Average wind speed in September: 9.2mph
The windiest month (with the highest average wind speed) is April (12.4mph).
The calmest month (with the lowest average wind speed) is August (8.9mph).
Average humidity in September
Altus, OK
- Average humidity in September: 58%
The months with the highest relative humidity are May and December (60%).
The month with the lowest relative humidity is August (49%).
Average rainfall in September
Altus, OK
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is May (3.35").
The driest months (with the least rainfall) are February and November (0.75").
Average rainfall days in September
Altus, OK
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in September
Altus, OK
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Altus, 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
Altus, OK
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 54min
The month with the most sunshine is June (Average sunshine: 11h and 30min).
The month with the least sunshine is December (Average sunshine: 6h and 30min).
Average sunshine days in September
Altus, OK
- Average sunshine days in September: 15.3 days
The month with the most sunshine days is January (25.9 days).
The month with the least sunshine days is August (15.1 days).
Average UV index in September
Altus, OK
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
Altus, OK
- Average cloud cover in September: 24
The month with the most cloud cover is March (Cloud cover 29).
The months with the least cloud cover are June and August (Cloud cover 17).
Average visibility in September
Altus, 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).





