September weather forecastPrinceton, AR
September
Weather in September
September, the first month of the autumn in Princeton, is also a hot month, with an average temperature fluctuating between 66°F (18.9°C) and 86.9°F (30.5°C).Temperature
The arrival of September is marked by a minor reduction in average high-temperature, sliding from a tropical 92.8°F (33.8°C) in August to a still hot 86.9°F (30.5°C). Princeton's nights in September cool down to an average low-temperature of 66°F (18.9°C).Heat index
The heat index value during September is evaluated at a very hot 98.6°F (37°C). Take greater precautions, heat exhaustion and heat cramps may be expected. Heatstroke could result from lengthy activity.Bear in mind that the heat index values are determined for shaded areas and light breezes. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.
When it comes to cooling down, the human body's primary method is through perspiration, making use of sweat evaporation to eliminate excess heat. When the air contains significant moisture, the efficiency of the evaporation process decreases, preventing the body from cooling down effectively and creating a feeling of overheating. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.
Humidity
In Princeton, the average relative humidity in September is 71%.Rainfall
In Princeton, in September, during 11.5 rainfall days, 1.77" (45mm) of precipitation is typically accumulated. In Princeton, during the entire year, the rain falls for 144.9 days and collects up to 29.17" (741mm) of precipitation.Snowfall
In Princeton, snow does not fall in April through November.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:44 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:55 pm CDT.
Sunshine
In Princeton, the average sunshine in September is 9.6h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Take precautions - Protection against sun damage is advised. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Princeton, AR
- Average high temperature in September: 86.9°F
The warmest month (with the highest average high temperature) is July (93.2°F).
The month with the lowest average high temperature is January (50.9°F).
- Average low temperature in September: 66°F
The month with the highest average low temperature is July (72.1°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in September
Princeton, AR
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Princeton, AR
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is April (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in September
Princeton, AR
- Average humidity in September: 71%
The months with the highest relative humidity are March and December (80%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Princeton, AR
- Average rainfall in September: 1.77"
The wettest month (with the highest rainfall) is April (3.23").
The driest month (with the least rainfall) is November (1.42").
Average rainfall days in September
Princeton, AR
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is July (16 days).
The month with the least rainy days is November (7.9 days).
Average snowfall in September
Princeton, AR
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Princeton, AR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.7 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, AR
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 9h and 36min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in September
Princeton, AR
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is October (20.3 days).
The months with the least sunshine days are July and August (12.4 days).
Average UV index in September
Princeton, AR
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Princeton, AR
- Average cloud cover in September: 29
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Princeton, AR
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
