Jacksonville
Florida, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Jacksonville, FL

Water geysers at the fountain of Jacksonville in Florida, with the cityscape
Water geysers at the fountain of Jacksonville in Florida, with the cityscape
The first month of the autumn, September, is also a hot month in Jacksonville, Florida, with temperature in the range of an average low of 69.4°F (20.8°C) and an average high of 86.9°F (30.5°C).

Temperature

In September, the average high-temperature is practically the same as in August - a still tropical 86.9°F (30.5°C). The average low-temperature, in Jacksonville, Florida, is 69.4°F (20.8°C).

Humidity

The most humid month is September, with an average relative humidity of 80.8%.

Rainfall

The month with the most rainfall is September when the rain falls for 12.2 days and typically aggregates up to 8.2" (208mm) of precipitation.

Ocean temperature

In Jacksonville, the average seawater temperature is 82.9°F (28.3°C). For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

In Jacksonville, the average length of the day in September is 12.3h.

Sunshine

The average sunshine is 7.6h.

UV index

In Jacksonville, the average daily maximum UV index is 9. A UV Index reading of 8 to 10 represents a very high health risk from the exposure to the Sun's UV rays for ordinary individuals.
In September, the average maximum UV index of 9 translate into the following recommendations:
Take special precautions, as unprotected skin can be damaged and can burn quickly. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in September in Jacksonville?

The average high-temperature, in September, in Jacksonville, Florida, is 86.9°F (30.5°C), while the average low-temperature is 69.4°F (20.8°C).

What is the most humid month in Jacksonville?

With an average relative humidity of 80.8%, September is the most humid month in Jacksonville.

What is the average humidity in September in Jacksonville?

In Jacksonville, Florida, the average relative humidity in September is 80.8%.

How many days does it rain in September in Jacksonville?

In Jacksonville, Florida, during September, the rain falls for 12.2 days and regularly aggregates up to 8.2" (208mm) of precipitation.

What is the wettest month in Jacksonville?

The month with the most rainfall in Jacksonville, Florida, is September when the rain falls for 12.2 days and typically aggregates up to 8.2" (208mm) of precipitation.

How warm is the water in September in Jacksonville?

In Jacksonville, Florida, in September, the average water temperature is 82.9°F (28.3°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.

How many hours of daylight does Jacksonville have in September?

In September, the average length of the day in Jacksonville is 12.3h.

How many hours of sunshine does Jacksonville have in September?

The average sunshine in September is 7.6h.

What is the UV index intensity in September in Jacksonville?

The average daily maximum UV index in September is 9. A UV Index estimate of 8 to 10 represents a very high hazard to health from unsafe exposure to the Sun's UV rays.
Average temperature in September - Jacksonville, FL
  • Average high temperature in September: 86.9°F

The warmest month (with the highest average high temperature) is July (92°F).
The month with the lowest average high temperature is January (64.8°F).

  • Average low temperature in September: 69.5°F

The month with the highest average low temperature is August (72.7°F).
The coldest month (with the lowest average low temperature) is January (41.4°F).

Average humidity in September - Jacksonville, FL
  • Average humidity in September: 80.8%

The month with the highest relative humidity is September (80.8%).
The month with the lowest relative humidity is April (69.5%).

Average rainfall in September - Jacksonville, FL
  • Average rainfall in September: 8.2"

The wettest month (with the highest rainfall) is September (8.2").
The driest month (with the lowest rainfall) is November (2.1").

Average rainfall days in September - Jacksonville, FL
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is August (15 days).
The month with the lowest number of rainy days is April (5.7 days).

Average sea temperature in September - Jacksonville, FL
  • Average sea temperature in September: 82.9°F

The best month for swimming (with the highest average sea temperature) is August (83.5°F).
The coldest month (with the lowest average sea temperature) is February (60.4°F).

Average daylight in September / Average sunshine in September - Jacksonville, FL
  • Average daylight in September: 12.3h

The month with the longest days is June (Average daylight: 14.1h).
The month with shortest days is December (Average daylight: 10.2h).

  • Average sunshine in September: 7.6h

The month with most sunshine is May (Average sunshine: 9.8h).
The month with least sunshine is December (Average sunshine: 5.9h).

Average UV index in September - Jacksonville, FL
  • Average UV index in September: 9

Months with the highest UV index are June and July (UV index 11).
Months with the lowest UV index are January and December (UV index 4).