September weather forecastFlynn, TX
September
Weather in September
September, the first month of the autumn in Flynn, is also a hot month, with an average temperature fluctuating between 68.9°F (20.5°C) and 88.7°F (31.5°C).Temperature
With the onset of September, the average high-temperature subtly recedes from August's torrid 95.9°F (35.5°C) to a hot 88.7°F (31.5°C). Throughout September, Flynn witnesses a nighttime temperature average of 68.9°F (20.5°C).Heat index
The heat index for September is calculated to be a fiery hot 102.2°F (39°C). Implement heightened safety measures - risk of heat exhaustion and heat cramps is increased. Prolonged activity may result in heatstroke.When considering the heat index, it's pivotal to note it is for shade and mild wind conditions. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This impact is subjective, influenced by the person's physical activity and individual heat perception, affected by factors including wind, attire, and metabolic differences. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
One way the human body deals with excessive warmth is by perspiring and allowing sweat to evaporate. Under high air temperature coupled with high humidity (high heat index), the body's perspiration is reduced, intensifying the sensation of heat. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.
Humidity
In September, the average relative humidity is 70%.Rainfall
In Flynn, in September, during 15.5 rainfall days, 2.56" (65mm) of precipitation is typically accumulated. Throughout the year, there are 149.4 rainfall days, and 30" (762mm) of precipitation is accumulated.Snowfall
Months with snowfall are January, February and September. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 1.1 snowfall days, and 0.47" (12mm) of snow is accumulated.Daylight
In Flynn, the average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 7:01 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 7:10 pm CDT.
Sunshine
The average sunshine in September is 8.4h.UV index
The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 6 suggests these recommendations:
Take precautions against overexposure. Protection against sun damage is needed. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Flynn, TX
- Average high temperature in September: 88.7°F
The warmest month (with the highest average high temperature) is August (95.9°F).
The month with the lowest average high temperature is January (56.8°F).
- Average low temperature in September: 68.9°F
The month with the highest average low temperature is August (73.9°F).
The coldest month (with the lowest average low temperature) is January (40.8°F).
Average pressure in September
Flynn, TX
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Flynn, TX
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is September (5.7mph).
Average humidity in September
Flynn, TX
- Average humidity in September: 70%
The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is August (65%).
Average rainfall in September
Flynn, TX
- Average rainfall in September: 2.56"
The wettest month (with the highest rainfall) is October (3.62").
The driest month (with the least rainfall) is February (1.69").
Average rainfall days in September
Flynn, TX
- Average rainfall days in September: 15.5 days
The month with the highest number of rainy days is September (15.5 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in September
Flynn, TX
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (0.28").
The months with the least snowfall are March, April, May, June, July, August, October, November and December (0").
Average snowfall days in September
Flynn, TX
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (0.6 days).
The months with the least snowfall days are March, April, May, June, July, August, October and November (0 days).
Average daylight in September /
Average sunshine in September
Flynn, TX
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).
- Average sunshine in September: 8h and 24min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
Flynn, TX
- Average sunshine days in September: 12.6 days
The month with the most sunshine days is January (19.8 days).
The month with the least sunshine days is September (12.6 days).
Average UV index in September
Flynn, TX
- Average UV index in September: 6
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 3).
Average cloud cover in September
Flynn, TX
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Flynn, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).





