Raleigh
North Carolina, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Raleigh, NC

The first month of the autumn, September, is also a moderately hot month in Raleigh, North Carolina, with temperature in the range of an average high of 81.7°F (27.6°C) and an average low of 64.4°F (18°C).

Temperature

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

Heat index

In September, 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.
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 'feels like', 'apparent temperature', 'real feel', or 'felt air temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (clothing, pregnancy, wind), and activity. 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 particularly important for children. 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

Months with the highest humidity are May, September and December, with an average relative humidity of 76%.

Rainfall

In Raleigh, during 13.4 rainfall days, 2.76" (70mm) of precipitation is typically accumulated. In Raleigh, North Carolina, during the entire year, the rain falls for 163.2 days and collects up to 32.2" (818mm) of precipitation.

Snowfall

In Raleigh, North Carolina, snow does not fall in April through October.

Daylight

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

Sunshine

In September, the average sunshine in Raleigh, North Carolina, is 9.1h.

UV index

In Raleigh, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against the skin and eye damage is obliged. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in September in Raleigh?

The average high-temperature, in September, in Raleigh, is 81.7°F (27.6°C), while the average low-temperature is 64.4°F (18°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), that combines air temperature and relative humidity, in September is evaluated 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?

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

How much does it rain in Raleigh in September?

In Raleigh, North Carolina, in September, during 13.4 rainfall days, 2.76" (70mm) of precipitation is typically accumulated.

When it does not snow in Raleigh?

April through October are months without snowfall in Raleigh.

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

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

How long on average sun shines in September in Raleigh?

In September, the average sunshine in Raleigh is 9.1h.

What is the UV index reading in September in Raleigh?

The average daily maximum UV index in September in Raleigh is 5. A UV Index estimate of 3 to 5 represents a medium health risk from the exposure to the Sun's UV rays.
Average temperature in September - Raleigh, NC
  • Average high temperature in September: 27.6°C

The warmest month (with the highest average high temperature) is July (31.9°C).
The month with the lowest average high temperature is January (8.9°C).

  • Average low temperature in September: 18°C

The month with the highest average low temperature is July (21.7°C).
The coldest month (with the lowest average low temperature) is January (0.5°C).

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: 70mm

The wettest month (with the highest rainfall) is August (87mm).
The driest month (with the least rainfall) is October (54mm).

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: 0mm

The month with the highest snowfall is January (37mm).
Months with the least snowfall are April, May, June, July, August, September and October (0mm).

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 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).