September weather forecastAllen, TX
September
Weather in September
The first month of the autumn, September, is still a tropical month in Allen, Texas, with an average temperature varying between 70°F (21.1°C) and 87.6°F (30.9°C).Temperature
The transition into September involves a small decrease in the average high-temperature, dipping slightly from a fiery hot 95.5°F (35.3°C) in August to a hot 87.6°F (30.9°C). Allen in September anticipates an average nighttime temperature of 70°F (21.1°C).Heat index
September's mean heat index is evaluated at a torrid 95°F (35°C). Incorporate additional safety actions, heat cramps and heat exhaustion are possible. Long-term activity may induce heatstroke.Heat index specifics point out values are for conditions of shade and a slight breeze. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', comes about by integrating the temperature readings with the humidity levels. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Should you be directly under the sun, anticipate a possible increase in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. Elevated relative humidity disrupts typical body cooling by reducing the evaporation rate, consequently decreasing the body's cooling rate and enhancing the feeling of heat. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.
Humidity
The average relative humidity in September is 63%.Rainfall
In Allen, in September, it is raining for 14.5 days, with typically 2.76" (70mm) of accumulated precipitation. In Allen, during the entire year, the rain falls for 143 days and collects up to 33.15" (842mm) of precipitation.Snowfall
In Allen, snow does not fall in March through October.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 7:01 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:12 pm CDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
In Allen, 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, a daily UV index of 6 turns into the following recommendations:
Deflect overexposure. Sun protection is a necessity. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete 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
Allen, TX
- Average high temperature in September: 87.6°F
The warmest month (with the highest average high temperature) is August (95.5°F).
The month with the lowest average high temperature is January (54°F).
- Average low temperature in September: 70°F
The month with the highest average low temperature is July (76.1°F).
The coldest month (with the lowest average low temperature) is January (38.7°F).
Average pressure in September
Allen, 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 (29.91"Hg).
Average wind speed in September
Allen, TX
- Average wind speed in September: 6.8mph
The windiest months (with the highest average wind speed) are March and April (9.9mph).
The calmest month (with the lowest average wind speed) is September (6.8mph).
Average humidity in September
Allen, 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 (56%).
Average rainfall in September
Allen, TX
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is October (4.21").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in September
Allen, TX
- Average rainfall days in September: 14.5 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is January (7.1 days).
Average snowfall in September
Allen, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.71").
The months with the least snowfall are March, April, May, June, July, August, September and October (0").
Average snowfall days in September
Allen, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Allen, 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 August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
Allen, TX
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is January (22.5 days).
The month with the least sunshine days is April (13.9 days).
Average UV index in September
Allen, 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
Allen, TX
- Average cloud cover in September: 29
The months with the most cloud cover are February and March (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in September
Allen, 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).





