September weather forecastPrinceton, TX
September
Weather in September
The first month of the autumn, September, is also a hot month in Princeton, Texas, with an average temperature ranging between max 87.1°F (30.6°C) and min 68.9°F (20.5°C).Temperature
In Princeton, entering September brings a subtle temperature decrement, reducing from August's 94.8°F (34.9°C) to a still tropical 87.1°F (30.6°C). In the month of September, the average low-temperature in Princeton usually rests at an agreeable 68.9°F (20.5°C).Heat index
During September, the heat index is calculated to be a fiery hot 95°F (35°C). Exercise heightened safety, heat cramps and heat exhaustion are probable. Persistent activity may provoke heatstroke.Be advised, the heat index considers values for conditions in shade and with a light breeze. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a single figure representing how weather conditions feel when combining temperature and humidity. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
When the body gets too warm, it perspires, leading to sweat evaporation which cools it down. 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. Overheating risks increase with rising body temperatures, especially if heat release isn't efficient.
Humidity
In Princeton, the average relative humidity in September is 65%.Rainfall
In Princeton, in September, during 15.1 rainfall days, 3.07" (78mm) of precipitation is typically accumulated. In Princeton, during the entire year, the rain falls for 144.7 days and collects up to 33.54" (852mm) of precipitation.Snowfall
March through October are months without snowfall.Daylight
In September, the average length of the day in Princeton is 12h and 22min.On the first day of the month, sunrise is at 7:00 am and sunset at 7:50 pm. On the last day of September, in Princeton, sunrise is at 7:20 am and sunset at 7:11 pm CDT.
Sunshine
In Princeton, Texas, the average sunshine in September is 8.5h.UV index
In Princeton, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In September, an average UV index of 6 transforms into the following instructions:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Princeton, TX
- Average high temperature in September: 87.1°F
The warmest month (with the highest average high temperature) is August (94.8°F).
The month with the lowest average high temperature is January (53.2°F).
- Average low temperature in September: 68.9°F
The month with the highest average low temperature is August (75.2°F).
The coldest month (with the lowest average low temperature) is January (37.9°F).
Average pressure in September
Princeton, 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
Princeton, TX
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is March (10.1mph).
The calmest month (with the lowest average wind speed) is September (6.8mph).
Average humidity in September
Princeton, TX
- Average humidity in September: 65%
The month with the highest relative humidity is May (76%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
Princeton, TX
- Average rainfall in September: 3.07"
The wettest month (with the highest rainfall) is October (4.17").
The driest month (with the least rainfall) is January (1.77").
Average rainfall days in September
Princeton, TX
- Average rainfall days in September: 15.1 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in September
Princeton, 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
Princeton, 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
Princeton, 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 6min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
Average sunshine days in September
Princeton, TX
- Average sunshine days in September: 13.6 days
The month with the most sunshine days is January (22.3 days).
The month with the least sunshine days is September (13.6 days).
Average UV index in September
Princeton, 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, November and December (UV index 3).
Average cloud cover in September
Princeton, TX
- Average cloud cover in September: 28
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
Princeton, 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).





