September weather forecast
Topsail Beach, NC

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Weather in September

The arrival of September in Topsail Beach signifies a mild retreat from summer, with temperatures lowering to an average high of 81.9°F (27.7°C). The sea remains invitingly warm, with temperatures averaging 80.4°F (26.9°C). The daylight hours start to significantly shorten, marking a shift towards the cozier months ahead. The weather retains a summer ambiance, with the UV index dropping to a moderate value of 6. Interestingly, September experiences the highest rainfall of the year, averaging 2.91" (74mm), indicating the start of fall showers.

Temperature

Topsail Beach, North Carolina, registers an average high-temperature of a still warm 81.9°F (27.7°C) at the commencement of September, closely related to the preceding month. In the month of September, the average temperature dips to an agreeable 72°F (22.2°C) during the night.

Heat index

September's heat index is calculated to be a tropical 87.8°F (31°C). With extended exposure and activity, one might feel exhausted and experience heat cramps.
Remember that heat index calculations are made for conditions in the shade with light wind. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', reflects the blend of air temperature and relative humidity to give a temperature impression. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.

Humidity

The average relative humidity in September is 76%.

Rainfall

The month with the most rainfall is September, when the rain falls for 14.4 days and typically aggregates up to 2.91" (74mm) of precipitation.

Snowfall

March through November are months without snowfall.

Ocean temperature

In Topsail Beach, in September, the average water temperature is 80.4°F (26.9°C).
Note: For engaging in water activities including swimming and diving, temperatures from 77°F (25°C) to 84.2°F (29°C) are perceived as perfect, providing pleasure for extended durations.

Daylight

The average length of the day in September is 12h and 23min.
On the first day of September, sunrise is at 6:44 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:55 pm EDT.

Sunshine

In Topsail Beach, the average sunshine in September is 9.6h.

UV index

In Topsail Beach, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for average individuals.
Note: The daily high UV index of 6 during September translates into the following recommendations:
Sidestep overexposure. Individuals with fair complexions risk burning in fewer than 20 minutes. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Stay cautious! Sand and water reflections increase UV radiation potency.
Updated: Aug 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

The high-temperature, in September, in Topsail Beach, is 81.9°F (27.7°C), while the low-temperature averages to 72°F (22.2°C). The average heat index (a.k.a. 'feels like', 'real feel'), which combines relative humidity and air temperature, in September is calculated to be 87.8°F (31°C).

What is the average humidity in September?

In Topsail Beach, the average relative humidity in September is 76%.

What is the rainiest month?

September is the month with the most rainfall in Topsail Beach. Rain falls for 14.4 days and accumulates 2.91" (74mm) of precipitation.

How many days does it rain in September?

In Topsail Beach, in September, it is raining for 14.4 days, with typically 2.91" (74mm) of accumulated precipitation.

When it does not snow?

March through November are months without snowfall.

How warm is the water in September?

In Topsail Beach, in September, the average water temperature is 80.4°F (26.9°C). Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

What is the average length of the day in September?

In Topsail Beach, the average day length in September is 12h and 23min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:44 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:55 pm EDT.

How long on average sun shines in September?

In September, the average sunshine duration in Topsail Beach is 9.6h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Topsail Beach, NC

Average temperature in September - Topsail Beach, NC
  • Average high temperature in September: 81.9°F

The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (54.5°F).

  • Average low temperature in September: 72°F

The month with the highest average low temperature is July (77°F).
The coldest month (with the lowest average low temperature) is January (42.4°F).

Average pressure in September
Topsail Beach, NC

Average pressure in September - Topsail Beach, NC
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).

Average wind speed in September
Topsail Beach, NC

Average wind speed in September - Topsail Beach, NC
  • Average wind speed in September: 9.3mph

The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).

Average humidity in September
Topsail Beach, NC

Average humidity in September - Topsail Beach, NC
  • Average humidity in September: 76%

The months with the highest relative humidity are August and December (77%).
The months with the lowest relative humidity are January and March (73%).

Average rainfall in September
Topsail Beach, NC

Average rainfall in September - Topsail Beach, NC
  • Average rainfall in September: 2.91"

The wettest month (with the highest rainfall) is September (2.91").
The driest month (with the least rainfall) is January (0.79").

Average rainfall days in September
Topsail Beach, NC

Average rainfall days in September - Topsail Beach, NC
  • Average rainfall days in September: 14.4 days

The month with the highest number of rainy days is August (19.5 days).
The month with the least rainy days is November (8.2 days).

Average snowfall in September
Topsail Beach, NC

Average snowfall in September - Topsail Beach, NC
  • Average snowfall in September: 0"

The months with the highest snowfall are January, February and December (0.04").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").

Average snowfall days in September
Topsail Beach, NC

Average snowfall days in September - Topsail Beach, NC
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (0.3 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).

Average sea temperature in September
Topsail Beach, NC

Average sea temperature in September - Topsail Beach, NC
  • Average sea temperature in September: 80.4°F

The best month for swimming (with the highest average sea temperature) is August (82.8°F).
The coldest month (with the lowest average sea temperature) is February (57.5°F).

Average daylight in September /
Average sunshine in September
Topsail Beach, NC

Average daylight in September / Average sunshine in September - Topsail Beach, NC
  • Average daylight in September: 12h and 2min

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 4min

The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).

Average sunshine days in September
Topsail Beach, NC

Average sunshine days in September - Topsail Beach, NC
  • Average sunshine days in September: 13.1 days

The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is August (8.2 days).

Average UV index in September
Topsail Beach, NC

Average UV index in September - Topsail Beach, NC
  • Average UV index in September: 6

The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).

Average cloud cover in September
Topsail Beach, NC

Average cloud cover in September - Topsail Beach, NC
  • Average cloud cover in September: 30

The months with the most cloud cover are February and December (Cloud cover 39).
The months with the least cloud cover are June and July (Cloud cover 26).

Average visibility in September
Topsail Beach, NC

Average visibility in September - Topsail Beach, NC
  • Average visibility in September: 6mi

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

Topsail Beach, North Carolina, USA

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