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 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 signals a slight drop in average high-temperature, sliding from August's hot 86.9°F (30.5°C) to a warm 81°F (27.2°C). In September, Allen records an average nighttime temperature of 59.9°F (15.5°C).Heat index
The average heat index in September is evaluated at a tropical 86°F (30°C). Continuing activity during long-lasting exposure might induce tiredness and result in heat cramps.Remember that heat index calculations are made for conditions in the shade with light wind. 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 'felt air temperature', melds the effects of warmth and moisture to generate a feeling of heat. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Humidity
In Allen, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.7 days and typically collects 2.32" (59mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 23min.On the first day of the month, sunrise is at 7:12 am and sunset at 8:06 pm. On the last day of September, sunrise is at 7:34 am and sunset at 7:24 pm EDT.
Sunshine
The average sunshine in September is 8.5h.UV index
In Allen, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 translates into these guidelines:
Act with care - The need to guard against sun damage is communicated. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Allen?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Allen have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Allen, TN
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (45.5°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (30.6°F).
Average pressure in September
Allen, TN
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Allen, TN
- Average wind speed in September: 4.2mph
The windiest months (with the highest average wind speed) are February, March and April (6.5mph).
The calmest months (with the lowest average wind speed) are July and August (3.9mph).
Average humidity in September
Allen, TN
- Average humidity in September: 76%
The month with the highest relative humidity is December (80%).
The months with the lowest relative humidity are June, August, October and November (75%).
Average rainfall in September
Allen, TN
- Average rainfall in September: 2.32"
The wettest months (with the highest rainfall) are July and December (4.29").
The driest month (with the least rainfall) is September (2.32").
Average rainfall days in September
Allen, TN
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is November (9.5 days).
Average snowfall in September
Allen, TN
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.02").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Allen, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Allen, TN
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 3min
The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
Allen, TN
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is October (18.6 days).
The month with the least sunshine days is July (10.2 days).
Average UV index in September
Allen, TN
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Allen, TN
- Average cloud cover in September: 31
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 30).
Average visibility in September
Allen, TN
- Average visibility in September: 6mi
The months with the highest visibility are February, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and March (5mi).
Allen, Tennessee, USA
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