September weather forecast and climate
Decatur, AL

The first month of the autumn, September, is also a moderately hot month in Decatur, Alabama, with average temperature varying between 63.7°F (17.6°C) and 83.1°F (28.4°C).

Temperature

In September, the average high-temperature is almost the same as in August - a warm 83.1°F (28.4°C). In Decatur, the average low-temperature is 63.7°F (17.6°C).

Heat index

In September, the average heat index is appraised at a tropical 89.8°F (32.1°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'real feel', 'feels like', or 'felt air temperature', is a measure that combines both air temperature and relative humidity into a single value that indicates how hot the weather feels. Additional factors like activity, differences in body mass, height, and shape, wind, and pregnancy affect individual temperature impact. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

In September, the average relative humidity is 74%.

Rainfall

Months with the least rainfall in Decatur are September and November Rain falls for 13.8 days and accumulates 2.48" (63mm) of rain.

Snowfall

April through October are months without snowfall.

Daylight

In September, the average length of the day in Decatur is 12.4h.

Sunshine

In September, the average sunshine is 8.8h.

UV index

In Decatur, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in September in Decatur?

The average high-temperature, in September, is 83.1°F (28.4°C), while the average low-temperature is 63.7°F (17.6°C). The average heat index (a.k.a. 'real feel', 'feels like'), that combines relative humidity and air temperature, in September is calculated to 89.8°F (32.1°C).

What is the average humidity in September in Decatur?

In September, the average relative humidity is 74%.

How much does it rain in Decatur in September?

In September, in Decatur, the rain falls for 13.8 days. Throughout September, 2.48" (63mm) of precipitation is accumulated.

What is the driest month in Decatur?

September and November are months with the least rain when the rain falls for 13.8 days and typically aggregates up to 2.48" (63mm) of rain.

When it does not snow in Decatur?

April through October are months without snowfall.

How many hours of daylight does Decatur have in September?

In September, the average length of the day in Decatur is 12.4h.

How long on average sun shines in September in Decatur?

The average sunshine in September in Decatur is 8.8h.

What is the UV index reading in September in Decatur?

In Decatur, Alabama, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health risk from the exposure to the Sun's UV rays.
Average temperature in September - Decatur, AL
  • Average high temperature in September: 83.1°F

The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is January (47.5°F).

  • Average low temperature in September: 63.7°F

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (33.3°F).

Average pressure in September - Decatur, AL
  • Average pressure in September: 30.02"

The month with the highest atmospheric pressure is January (30.17").
The month with the lowest atmospheric pressure is June (29.98").

Average wind speed in September - Decatur, AL
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is February (8.6mph).
The calmest month (with the lowest average wind speed) is July (4.8mph).

Average humidity in September - Decatur, AL
  • Average humidity in September: 74%

The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September - Decatur, AL
  • Average rainfall in September: 2.48"

The wettest month (with the highest rainfall) is December (4.45").
The driest months (with the least rainfall) are September and November (2.48").

Average rainfall days in September - Decatur, AL
  • Average rainfall days in September: 13.8 days

The month with the highest number of rainy days is July (20 days).
The month with the least rainy days is November (10.4 days).

Average snowfall in September - Decatur, AL
  • Average snowfall in September: 0"

Months with the highest snowfall are January and February (0.55").
Months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September - Decatur, AL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (2.5 days).
Months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September / Average sunshine in September - Decatur, AL
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.4h).
The month with the shortest days is December (Average daylight: 9.9h).

  • Average sunshine in September: 8.8h

The month with the most sunshine is June (Average sunshine: 10.5h).
The month with the least sunshine is February (Average sunshine: 4.6h).

Average sunshine days in September - Decatur, AL
  • Average sunshine days in September: 13.9 days

The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is July (8.8 days).

Average UV index in September - Decatur, AL
  • Average UV index in September: 5

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January and December (UV index 2).

Average cloud cover in September - Decatur, AL
  • Average cloud cover in September: 30

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is June (Cloud cover 29).

Average visibility in September - Decatur, AL
  • Average visibility in September: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).