September weather forecast and climate
Raleigh, NC

The George Washington statue overlooking the city buildings of Raleigh, North Carolina
The George Washington statue overlooking the city buildings of Raleigh, North Carolina
The first month of the autumn, September, is also a moderately hot month in Raleigh, North Carolina, with average temperature varying between 64.4°F (18°C) and 81.7°F (27.6°C).

Temperature

In Raleigh, the average high-temperature in September marginally drops, from a tropical 87.3°F (30.7°C) in August, to a moderately hot 81.7°F (27.6°C). In September, the average low-temperature is 64.4°F (18°C).

Heat index

The average heat index is estimated at a tropical 87.1°F (30.6°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'felt air temperature', 'apparent temperature', or 'feels like', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. Additional factors like pregnancy, clothing, metabolic differences, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

May, September and December, with an average relative humidity of 76%, are most humid months in Raleigh.

Rainfall

In Raleigh, during September, the rain falls for 13.4 days and regularly aggregates up to 2.76" (70mm) of precipitation. Throughout the year, in Raleigh, there are 163.2 rainfall days, and 32.2" (818mm) of precipitation is accumulated.

Snowfall

In Raleigh snow does not fall in April through October.

Daylight

In Raleigh, the average length of the day is 12.4h.

Sunshine

The average sunshine in September is 9.1h.

UV index

In Raleigh, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from the exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 5 in September transform into the following instructions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Raleigh?

In Raleigh, in September, the average high-temperature is 81.7°F (27.6°C), and the average low-temperature is 64.4°F (18°C). In September, the average heat index (a.k.a. 'feels like', 'felt air temperature'), that factores the actual air temperature with the relative humidity, is estimated at 87.1°F (30.6°C).

What are the most humid months in Raleigh?

May, September and December, with an average relative humidity of 76%, are most humid months in Raleigh, North Carolina.

What is the average humidity in September in Raleigh?

In Raleigh, North Carolina, the average relative humidity in September is 76%.

How many days does it rain in September in Raleigh?

In Raleigh, North Carolina, in September, it is raining for 13.4 days, with typically 2.76" (70mm) of accumulated precipitation.

When it does not snow in Raleigh?

In Raleigh snow does not fall in April through October.

What is the average length of the day in September in Raleigh?

In Raleigh, North Carolina, the average length of the day in September is 12.4h.

How many hours of sunshine does Raleigh have in September?

In September, the average sunshine is 9.1h.

What is the UV index intensity in September in Raleigh?

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium hazard to health from unsafe exposure to the Sun's UV rays.
Average temperature in September - Raleigh, NC
  • Average high temperature in September: 81.7°F

The warmest month (with the highest average high temperature) is July (89.4°F).
The month with the lowest average high temperature is January (48°F).

  • Average low temperature in September: 64.4°F

The month with the highest average low temperature is July (71.1°F).
The coldest month (with the lowest average low temperature) is January (32.9°F).

Average pressure in September - Raleigh, NC
  • Average pressure in September: 30.03"

The month with the highest atmospheric pressure is November (30.15").
The month with the lowest atmospheric pressure is June (29.96").

Average wind speed in September - Raleigh, NC
  • Average wind speed in September: 6.1mph

The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in September - Raleigh, NC
  • Average humidity in September: 76%

Months with the highest relative humidity are May, September and December (76%).
Months with the lowest relative humidity are January, March, April, June, July and November (73%).

Average rainfall in September - Raleigh, NC
  • Average rainfall in September: 2.76"

The wettest month (with the highest rainfall) is August (3.43").
The driest month (with the least rainfall) is October (2.13").

Average rainfall days in September - Raleigh, NC
  • Average rainfall days in September: 13.4 days

The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is November (9.1 days).

Average snowfall in September - Raleigh, NC
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.46").
Months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September - Raleigh, NC
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (2.1 days).
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 - Raleigh, NC
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.6h).
The month with the shortest days is December (Average daylight: 9.8h).

  • Average sunshine in September: 9.1h

Months with the most sunshine are June and July (Average sunshine: 10.8h).
The month with the least sunshine is December (Average sunshine: 5.5h).

Average sunshine days in September - Raleigh, NC
  • Average sunshine days in September: 15.1 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (10.5 days).

Average UV index in September - Raleigh, NC
  • Average UV index in September: 5

Months with the highest UV index are June and July (UV index 7).
The month with the lowest UV index is January (UV index 2).

Average cloud cover in September - Raleigh, NC
  • Average cloud cover in September: 35

The month with the most cloud cover is February (Cloud cover 42).
The month with the least cloud cover is June (Cloud cover 30).

Average visibility in September - Raleigh, NC
  • 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).