Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's arrival aligns with a minor decrease in average high-temperatures, from August's sweltering 95°F (35°C) to a tropical 89.6°F (32°C). In Calallen, an average nighttime temperature of 76.5°F (24.7°C) is expected during September.Heat index
During September, the heat index is estimated at a scorching 104°F (40°C). Additional precautions are required to avert heat cramps and heat exhaustion. Persistent activity may culminate in heatstroke.It is worth noting that heat index values are gauged for conditions in the shade and light breezes. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a measure of how hot it feels when the actual air humidity is factored in. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. 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.
Perspiration, which is the evaporation of sweat, is a primary way the human body manages and dispels excessive warmth. A surge in relative humidity can disrupt the body's normal cooling function by slowing evaporation, hence reducing the rate at which the body cools and intensifying the perception of heat. Excessive heat gain, when not shed effectively by the body, can result in increasing body temperatures and related hazards.
Humidity
The average relative humidity in September is 70%.Rainfall
The month with the most rainfall is September, when the rain falls for 16.5 days and typically aggregates up to 2.48" (63mm) of precipitation.Snowfall
In Calallen, snow does not fall in January, March through December.Daylight
In Calallen, the average length of the day in September is 12h and 19min.On the first day of September, sunrise is at 7:09 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 7:17 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
The average daily maximum UV index in September is 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for average individuals.Note: In September, the maximum UV index of 7 transforms into these recommendations:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
What is the wettest month?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Calallen have in September?
What time are sunrise and sunset in September in Calallen?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Calallen, TX
- Average high temperature in September: 89.6°F
The warmest month (with the highest average high temperature) is August (95°F).
The month with the lowest average high temperature is January (64.9°F).
- Average low temperature in September: 76.5°F
The month with the highest average low temperature is August (79°F).
The coldest month (with the lowest average low temperature) is January (50.4°F).
Average pressure in September
Calallen, TX
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are May and June (29.88"Hg).
Average wind speed in September
Calallen, TX
- Average wind speed in September: 8.3mph
The windiest month (with the highest average wind speed) is May (11.1mph).
The calmest month (with the lowest average wind speed) is September (8.3mph).
Average humidity in September
Calallen, TX
- Average humidity in September: 70%
The month with the highest relative humidity is May (75%).
The month with the lowest relative humidity is August (66%).
Average rainfall in September
Calallen, TX
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is September (2.48").
The driest month (with the least rainfall) is August (0.71").
Average rainfall days in September
Calallen, TX
- Average rainfall days in September: 16.5 days
The month with the highest number of rainy days is September (16.5 days).
The month with the least rainy days is August (7.1 days).
Average snowfall days in September
Calallen, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Calallen, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 54min).
The month with the shortest days is December (Average daylight: 10h and 24min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).
Average sunshine days in September
Calallen, TX
- Average sunshine days in September: 11.3 days
The month with the most sunshine days is July (21.6 days).
The month with the least sunshine days is September (11.3 days).
Average UV index in September
Calallen, TX
- Average UV index in September: 7
The month with the highest UV index is July (UV index 8).
The months with the lowest UV index are January and December (UV index 4).
Average cloud cover in September
Calallen, TX
- Average cloud cover in September: 30
The months with the most cloud cover are February and December (Cloud cover 46).
The month with the least cloud cover is August (Cloud cover 19).
Average visibility in September
Calallen, 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).
Calallen, Texas, USA
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