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September Weather in Jacksonville, United States

Last updated: June 24, 2025

In September, the average temperature in Jacksonville, United States is a pleasant 26°C (80°F). Expect a minimum of 17°C (63°F) and a maximum of 36°C (97°F), perfect for both cozy and warm days. With an average precipitation of 137 mm (5.4 in) spread across 16 days, and humidity levels around 83%, it’s wise to pack for some refreshing rain while enjoying the tropical heat!

September Temperature in Jacksonville

In September in Jacksonville, the average temperature is 26°C (80°F). Maximum temperatures can reach 36°C (97°F), while minimums can drop as low as 17°C (63°F). This pleasant climate makes Jacksonville an ideal destination for travelers seeking warm and comfortable weather.

September Weather in Jacksonville: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Jacksonville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Jacksonville, September typically has an average temperature of 26°C (80°F), with highs reaching up to 36°C (97°F) and lows dropping to around 17°C (63°F).
JanFebMarAprMayJunJulAugSepOctNovDec566264707679818180746359
Data source: Temperature data for Jacksonville generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Jacksonville

In Jacksonville in September, the precipitation amount is 137 mm (5.4 in) over the course of 16 days.

September Precipitation Trends in Jacksonville

The chart displays monthly precipitation patterns in Jacksonville, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Jacksonville, September typically receives around 137 mm (5.4 inches) of precipitation spread over approximately 16 days.
JanFebMarAprMayJunJulAugSepOctNovDec4370417187157184164137776579
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Jacksonville

In Jacksonville in September humidity is 83%. With an average temperature of 26°C (80°F), this humidity feels like a warm, enveloping blanket that can make traveling quite uncomfortable; you may find yourself needing frequent breaks for hydration and cool shade as the thick air clings to your skin.

September Average Humidity in Jacksonville

This chart illustrates the average monthly humidity levels in Jacksonville, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Jacksonville is approximately 83%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%79%78%73%72%74%82%82%83%79%82%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Jacksonville

In Jacksonville in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Jacksonville.

Maximum UV Index Levels in Jacksonville for September

The chart shows the monthly maximum UV Index (UVI) for Jacksonville in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Jacksonville typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec579111111111110865
Data source: Jacksonville September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Jacksonville Compares to Other Months

Weather in Jacksonville varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Jacksonville, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Jacksonville, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather13°C (56°F)43 mm (1.7 inches)84%moderate
February Weather17°C (62°F)70 mm (2.8 inches)79%high
March Weather18°C (65°F)41 mm (1.6 inches)78%very high
April Weather21°C (70°F)71 mm (2.8 inches)72%extreme
May Weather24°C (76°F)87 mm (3.4 inches)72%extreme
June Weather26°C (80°F)157 mm (6.2 inches)74%extreme
July Weather27°C (81°F)184 mm (7.2 inches)82%extreme
August Weather27°C (82°F)164 mm (6.4 inches)82%extreme
September Weather26°C (80°F)137 mm (5.4 inches)83%very high
October Weather24°C (75°F)77 mm (3.0 inches)79%very high
November Weather17°C (64°F)65 mm (2.6 inches)82%high
December Weather15°C (59°F)79 mm (3.1 inches)85%moderate

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