September weather forecast
Johnson City, TN

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The front entrance to the Public Library in Johnson City, Tennessee
The front entrance to the Public Library in Johnson City, Tennessee

Weather in September

September serves as a bridge between the sultry summer and the crisp autumn in Johnson City. The distinctive onset of cooler temperatures and shorter days earmarks the change of season. While nestled in the quintessential charm of summer, the city begins to showcase colorful leaves and cooler evenings. Precipitation declines to 1.77" (45mm), permitting observers to appreciate the clear skies and changing foliage. As the daylight recedes, the sun holds its ground, continuing to radiate warmth and brightness throughout September.

Temperature

Entering September, the average high-temperature is recorded at a still warm 77.5°F (25.3°C), exhibiting a minimal shift from August's 82.6°F (28.1°C). Johnson City reports a marked divergence from daytime peaks throughout September, with lows averaging at a cool 54.9°F (12.7°C).

Humidity

In Johnson City, the average relative humidity in September is 77%.

Rainfall

September is the month with the least rainfall. Rain falls for 15.5 days and accumulates 1.77" (45mm) of precipitation.

Snowfall

May through September are months without snowfall in Johnson City.

Daylight

In Johnson City, the average length of the day in September is 12h and 24min.
On the first day of September, sunrise is at 7:01 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:13 pm EDT.

Sunshine

In Johnson City, the average sunshine in September is 8.7h.

UV index

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.
Note: A daily high UV index of 4 in September leads to these guidelines:
Put precautions into practice - Guidance to elude sunburn is provided. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.

Frequently asked questions

What are September temperatures?

September temperatures vary between a high-temperature of 77.5°F (25.3°C) and a low-temperature of 54.9°F (12.7°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is computed to be 89.6°F (32°C).

What is the average humidity in September?

In Johnson City, the average relative humidity in September is 77%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 15.5 days and accumulates 1.77" (45mm) of precipitation.

How much does it rain in Johnson City in September?

In Johnson City, Tennessee, during September, the rain falls for 15.5 days and regularly aggregates up to 1.77" (45mm) of precipitation.

When it does not snow?

In Johnson City, snow does not fall in May through September.

Does it snow in September?

In Johnson City, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Johnson City have in September?

The average day length in September in Johnson City is 12h and 24min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 7:01 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:13 pm EDT.

How many hours of sunshine does Johnson City have in September?

In September, the average sunshine duration is 8.7h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability 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
Johnson City, TN

Average temperature in September - Johnson City, TN
  • Average high temperature in September: 77.5°F

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (41.5°F).

  • Average low temperature in September: 54.9°F

The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (26.6°F).

Average pressure in September
Johnson City, TN

Average pressure in September - Johnson City, TN
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).

Average wind speed in September
Johnson City, TN

Average wind speed in September - Johnson City, TN
  • Average wind speed in September: 4mph

The windiest month (with the highest average wind speed) is April (6.6mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).

Average humidity in September
Johnson City, TN

Average humidity in September - Johnson City, TN
  • Average humidity in September: 77%

The months with the highest relative humidity are February and December (79%).
The month with the lowest relative humidity is November (75%).

Average rainfall in September
Johnson City, TN

Average rainfall in September - Johnson City, TN
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is February (3.27").
The driest month (with the least rainfall) is September (1.77").

Average rainfall days in September
Johnson City, TN

Average rainfall days in September - Johnson City, TN
  • Average rainfall days in September: 15.5 days

The month with the highest number of rainy days is July (19.6 days).
The month with the least rainy days is November (11.2 days).

Average snowfall in September
Johnson City, TN

Average snowfall in September - Johnson City, TN
  • Average snowfall in September: 0"

The month with the highest snowfall is December (3.74").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Johnson City, TN

Average snowfall days in September - Johnson City, TN
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Johnson City, TN

Average daylight in September / Average sunshine in September - Johnson City, 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 4min

The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 5h and 0min).

Average sunshine days in September
Johnson City, TN

Average sunshine days in September - Johnson City, TN
  • Average sunshine days in September: 11.9 days

The month with the most sunshine days is October (16.5 days).
The month with the least sunshine days is July (8.3 days).

Average UV index in September
Johnson City, TN

Average UV index in September - Johnson City, TN
  • Average UV index in September: 4

The months with the highest UV index are 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
Johnson City, TN

Average cloud cover in September - Johnson City, TN
  • Average cloud cover in September: 33

The month with the most cloud cover is February (Cloud cover 52).
The months with the least cloud cover are June and August (Cloud cover 31).

Average visibility in September
Johnson City, TN

Average visibility in September - Johnson City, TN
  • Average visibility in September: 5mi

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

Johnson City, Tennessee, USA

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