September weather forecastKeller, TX
September
Weather in September
The first month of the autumn, September, is still a hot month in Keller, Texas, with temperature in the range of an average high of 87.4°F (30.8°C) and an average low of 69.6°F (20.9°C).Temperature
The arrival of September correlates with a minor temperature reduction, down from August's very hot 95.9°F (35.5°C) to a hot 87.4°F (30.8°C). An average low-temperature of 69.6°F (20.9°C) is observed during the September nights.Heat index
September's average heat index is evaluated at a fiery hot 95°F (35°C). Greater safety measures are needed, risk of heat exhaustion and heat cramps is high. Continuous activity might trigger heatstroke.When referencing the heat index, its values are suitable for shady environments and light breezes. In the presence of direct sunshine, the heat index could be augmented by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', gauges the sensation of temperature factoring in the air's moisture content. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Awareness of direct sun exposure is crucial as it has the potential to heighten the weather's effects, pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. Excessive relative humidity disturbs the body's typical cooling process by reducing evaporation, leading to a decrease in body cooling rate and an increase in the sensation of warmth. Accumulating more heat than the body can dissipate leads to an uptick in body temperature, with potential heat stress consequences.
Humidity
In Keller, Texas, the average relative humidity in September is 63%.Rainfall
In Keller, during September, the rain falls for 10.7 days and regularly aggregates up to 1.38" (35mm) of precipitation. Throughout the year, there are 100.6 rainfall days, and 13.94" (354mm) of precipitation is accumulated.Snowfall
In Keller, snow does not fall in January, April through November.Daylight
In Keller, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 7:03 am and sunset at 7:53 pm. On the last day of September, in Keller, sunrise is at 7:22 am and sunset at 7:14 pm CDT.
Sunshine
In Keller, the average sunshine in September is 8.5h.UV index
In Keller, Texas, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A maximum UV index of 6 in September translates into the following recommendations:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Keller, TX
- Average high temperature in September: 87.4°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 (54.5°F).
- Average low temperature in September: 69.6°F
The months with the highest average low temperature are July and August (75.7°F).
The coldest month (with the lowest average low temperature) is January (38.3°F).
Average pressure in September
Keller, TX
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Keller, TX
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is September (6.8mph).
Average humidity in September
Keller, TX
- Average humidity in September: 63%
The month with the highest relative humidity is May (73%).
The month with the lowest relative humidity is August (55%).
Average rainfall in September
Keller, TX
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days in September
Keller, TX
- Average rainfall days in September: 10.7 days
The month with the highest number of rainy days is May (11.9 days).
The month with the least rainy days is January (4 days).
Average snowfall in September
Keller, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.31").
The months with the least snowfall are January, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Keller, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.8 days).
The months with the least snowfall days are January, April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Keller, TX
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Keller, TX
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is January (26.2 days).
The month with the least sunshine days is May (15.9 days).
Average UV index in September
Keller, 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
Keller, TX
- Average cloud cover in September: 29
The month with the most cloud cover is March (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 19).
Average visibility in September
Keller, TX
- 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).
