September weather forecast
Royal Blue, TN

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Weather in September

The first month of the autumn, September, is still a warm month in Royal Blue, Tennessee, with an average temperature varying between 57.2°F (14°C) and 79.2°F (26.2°C).

Temperature

Royal Blue records a mild change in average high-temperature during September, easing from 84.9°F (29.4°C) in August to a still warm 79.2°F (26.2°C). Royal Blue, after hot September days, encounters a marked drop to an average nighttime temperature of 57.2°F (14°C).

Humidity

In September, the average relative humidity is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.6 days and accumulates 1.89" (48mm) of precipitation.

Snowfall

In Royal Blue, snow does not fall in May through October.

Daylight

The average length of the day in September is 12h and 24min.
On the first day of September, sunrise is at 7:09 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:21 pm EDT.

Sunshine

In Royal Blue, the average sunshine in September is 8.4h.

UV index

The average daily maximum UV index in September in Royal Blue is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Guard yourself - Avoiding sunburn is suggested. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.

Frequently asked questions

What are the temperatures in September?

In September, the average high-temperature and low-temperature are 79.2°F (26.2°C) and 57.2°F (14°C) respectively. In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is appraised at 95°F (35°C).

What is the average humidity in September?

In September, the average relative humidity is 78%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 12.6 days and accumulates 1.89" (48mm) of precipitation.

How much does it rain in September?

In September, the rain falls for 12.6 days. Throughout September, 1.89" (48mm) of precipitation is accumulated.

When it does not snow?

May through October are months without snowfall.

What is the average length of the day in September?

In Royal Blue, the average day length in September is 12h and 24min.

When is the sunrise / sunset in September in Royal Blue?

On the first day of September, sunrise is at 7:09 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:21 pm EDT.

How long on average sun shines in September?

In Royal Blue, the average sunshine duration in September is 8.4h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health threat 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
Royal Blue, TN

Average temperature in September - Royal Blue, TN
  • Average high temperature in September: 79.2°F

The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is January (42.3°F).

  • Average low temperature in September: 57.2°F

The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).

Average pressure in September
Royal Blue, TN

Average pressure in September - Royal Blue, TN
  • Average pressure in September: 30.04"Hg

The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).

Average wind speed in September
Royal Blue, TN

Average wind speed in September - Royal Blue, TN
  • Average wind speed in September: 3.7mph

The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).

Average humidity in September
Royal Blue, TN

Average humidity in September - Royal Blue, TN
  • Average humidity in September: 78%

The months with the highest relative humidity are February and December (81%).
The month with the lowest relative humidity is August (76%).

Average rainfall in September
Royal Blue, TN

Average rainfall in September - Royal Blue, TN
  • Average rainfall in September: 1.89"

The wettest month (with the highest rainfall) is February (3.94").
The driest month (with the least rainfall) is September (1.89").

Average rainfall days in September
Royal Blue, TN

Average rainfall days in September - Royal Blue, TN
  • Average rainfall days in September: 12.6 days

The month with the highest number of rainy days is July (19.3 days).
The month with the least rainy days is November (9.4 days).

Average snowfall in September
Royal Blue, TN

Average snowfall in September - Royal Blue, TN
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Royal Blue, TN

Average snowfall days in September - Royal Blue, TN
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (5.5 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
Royal Blue, TN

Average daylight in September / Average sunshine in September - Royal Blue, 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 42min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).

Average sunshine days in September
Royal Blue, TN

Average sunshine days in September - Royal Blue, TN
  • Average sunshine days in September: 15.5 days

The month with the most sunshine days is October (18.8 days).
The month with the least sunshine days is July (10.1 days).

Average UV index in September
Royal Blue, TN

Average UV index in September - Royal Blue, 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 January, February and December (UV index 2).

Average cloud cover in September
Royal Blue, TN

Average cloud cover in September - Royal Blue, TN
  • Average cloud cover in September: 35

The month with the most cloud cover is February (Cloud cover 56).
The months with the least cloud cover are June and August (Cloud cover 32).

Average visibility in September
Royal Blue, TN

Average visibility in September - Royal Blue, TN
  • Average visibility in September: 5mi

The month with the highest visibility is November (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October and December (5mi).

Royal Blue, Tennessee, USA

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