September weather forecast
Harbor Isles, TN

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Weather in September

The first month of the autumn, September, is still a warm month in Harbor Isles, Tennessee, with temperature in the range of an average low of 62.6°F (17°C) and an average high of 81.9°F (27.7°C).

Temperature

A minor decrease in the average high-temperature is observed during September, shifting from a tropical 88°F (31.1°C) in August to a moderately hot 81.9°F (27.7°C). During September, Harbor Isles experiences an average low-temperature of 62.6°F (17°C) at night.

Heat index

Throughout September, the heat index is appraised at a hot 87.8°F (31°C). Uninterrupted exposure and activity might result in fatigue, potentially causing heat cramps.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'apparent temperature' or 'real feel', reflects the feeling of heat when considering both air temperature and humidity. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are especially crucial for babies and toddlers. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.

Humidity

The average relative humidity in September is 74%.

Rainfall

In Harbor Isles, during September, the rain falls for 12.1 days and regularly aggregates up to 1.5" (38mm) of precipitation. Throughout the year, there are 150.1 rainfall days, and 24.41" (620mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 23min.
On the first day of September, sunrise is at 6:18 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 6:30 pm CDT.

Sunshine

In Harbor Isles, the average sunshine in September is 8.4h.

UV index

In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Exercise prevention - Warding off sunburn is urged. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The average high-temperature and low-temperature during September are 81.9°F (27.7°C) and 62.6°F (17°C) respectively. The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines relative humidity and air temperature, in September is appraised at 87.8°F (31°C).

What is the average humidity in September?

In Harbor Isles, the average relative humidity in September is 74%.

How many days does it rain in September?

In Harbor Isles, Tennessee, in September, during 12.1 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.

When it does not snow?

In Harbor Isles, Tennessee, snow does not fall in May through October.

How many hours of daylight does Harbor Isles have in September?

The average day length in September is 12h and 23min.

When is the sunrise / sunset in September in Harbor Isles?

In September, on the first day of the month, sunrise is at 6:18 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 6:30 pm CDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.4h.

What is the UV index reading in September?

In Harbor Isles, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from 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
Harbor Isles, TN

Average temperature in September - Harbor Isles, TN
  • Average high temperature in September: 81.9°F

The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is January (45.1°F).

  • Average low temperature in September: 62.6°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 (30.7°F).

Average pressure in September
Harbor Isles, TN

Average pressure in September - Harbor Isles, TN
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).

Average wind speed in September
Harbor Isles, TN

Average wind speed in September - Harbor Isles, TN
  • Average wind speed in September: 4.8mph

The windiest month (with the highest average wind speed) is February (8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).

Average humidity in September
Harbor Isles, TN

Average humidity in September - Harbor Isles, TN
  • Average humidity in September: 74%

The month with the highest relative humidity is December (78%).
The months with the lowest relative humidity are June, August and October (73%).

Average rainfall in September
Harbor Isles, TN

Average rainfall in September - Harbor Isles, TN
  • Average rainfall in September: 1.5"

The wettest month (with the highest rainfall) is July (3.19").
The driest month (with the least rainfall) is November (1.38").

Average rainfall days in September
Harbor Isles, TN

Average rainfall days in September - Harbor Isles, TN
  • Average rainfall days in September: 12.1 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is November (7.7 days).

Average snowfall in September
Harbor Isles, TN

Average snowfall in September - Harbor Isles, TN
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.71").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Harbor Isles, TN

Average snowfall days in September - Harbor Isles, TN
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (3.5 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
Harbor Isles, TN

Average daylight in September / Average sunshine in September - Harbor Isles, TN
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • Average sunshine in September: 8h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 24min).

Average sunshine days in September
Harbor Isles, TN

Average sunshine days in September - Harbor Isles, TN
  • Average sunshine days in September: 15.6 days

The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is July (11.8 days).

Average UV index in September
Harbor Isles, TN

Average UV index in September - Harbor Isles, 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 February and December (UV index 2).

Average cloud cover in September
Harbor Isles, TN

Average cloud cover in September - Harbor Isles, TN
  • Average cloud cover in September: 32

The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is June (Cloud cover 30).

Average visibility in September
Harbor Isles, TN

Average visibility in September - Harbor Isles, TN
  • 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).

Harbor Isles, Tennessee, USA

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