September weather forecast
St. Augustine, FL

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Palm trees and colorful houses in front of water fountains in a popular town square in St. Augustine, Florida
Palm trees and colorful houses in front of water fountains in a popular town square in St. Augustine, Florida

Weather in September

As summer winds down, September brings a combinative climatic pattern to St. Augustine, Florida. The city starts witnessing shortened daylight hours, yet the weather retains the warmth typical of the summer months. However, the month bagged highest rainfall measuring an impressive 7.5" (191mm). Despite the rainy period, sun-seekers can still expect exceedingly generous doses of sunshine. Consequently, the city emanates an indomitable spirit in September, overcoming the rains with a radiant disposition.

Temperature

The unfolding of September in St. Augustine shows an average high-temperature of a still tropical 86°F (30°C), indicating a slight variance from August's 89.1°F (31.7°C). During the month of September, an average low-temperature of 71.1°F (21.7°C) is recorded in St. Augustine.

Rainfall

September is the month with the most rainfall in St. Augustine, Florida. Rain falls for 13 days and accumulates 7.52" (191mm) of precipitation.

Ocean temperature

In St. Augustine, in September, the average water temperature is 83.1°F (28.4°C).
Note: Water temperatures between 77°F (25°C) and 84.2°F (29°C) are ideal for swimming, diving, and other activities, ensuring comfort and enjoyment for lengthened periods.

Daylight

In September, the average length of the day in St. Augustine is 12h and 20min.
On the first day of September in St. Augustine, sunrise is at 7:02 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 7:11 pm EDT.

Sunshine

The average sunshine in September in St. Augustine is 8h.

UV index

In September, the average daily maximum UV index in St. Augustine, Florida, is 9. A UV Index value of 8 to 10 symbolizes a very high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum UV index of 9 in September translates into the following recommendations:
Always stay safe. Unprotected skin and eyes can get damaged rapidly. Between 10 a.m. and 4 p.m., the Sun emits the most powerful UV radiation. Limit direct exposure to the Sun during these hours. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Applying and reapplying liberally a broad-spectrum sunscreen of SPF 30+ every two hours, and straight after a swim or outdoor activity is recommended. Caution! The Sun's UV rays become stronger due to reflections from water and sand.

Frequently asked questions

How hot is September?

In September, the average high-temperature and low-temperature are 86°F (30°C) and 71.1°F (21.7°C) respectively.

What is the wettest month?

September is the month with the most rainfall in St. Augustine. Rain falls for 13 days and accumulates 7.52" (191mm) of precipitation.

How much does it rain in September?

In St. Augustine, during September, the rain falls for 13 days and regularly aggregates up to 7.52" (191mm) of precipitation.

What is the ocean temperature in September in St. Augustine?

In September, the average ocean temperature is 83.1°F (28.4°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

What is the average length of the day in September?

In September, the average day length is 12h and 20min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 7:02 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 7:11 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 9. A UV Index reading of 8 to 10 represents a very high health vulnerability from unsafe exposure to Sun's UV rays.
Average rainfall days
Average daylight
Average sunshine
Average UV index

Average temperature in September
St. Augustine, FL

Average temperature in September - St. Augustine, FL
  • Average high temperature in September: 86°F

The warmest month (with the highest average high temperature) is July (90°F).
The month with the lowest average high temperature is January (66°F).

  • Average low temperature in September: 71°F

The month with the highest average low temperature is August (73°F).
The coldest month (with the lowest average low temperature) is January (46°F).

Average rainfall in September
St. Augustine, FL

Average rainfall in September - St. Augustine, FL
  • Average rainfall in September: 7.5"

The wettest month (with the highest rainfall) is September (7.5").
The driest month (with the least rainfall) is November (2.3").

Average rainfall days in September
St. Augustine, FL

Average rainfall days in September - St. Augustine, FL
  • Average rainfall days in September: 13 days

The months with the highest number of rainy days are July and August (15 days).
The month with the least rainy days is April (6 days).

Average sea temperature in September
St. Augustine, FL

Average sea temperature in September - St. Augustine, FL
  • Average sea temperature in September: 83.2°F

The best month for swimming (with the highest average sea temperature) is August (83.8°F).
The coldest months (with the lowest average sea temperature) are January and February (64.3°F).

Average daylight in September /
Average sunshine in September
St. Augustine, FL

Average daylight in September / Average sunshine in September - St. Augustine, FL
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).

  • Average sunshine in September: 8h

The months with the most sunshine are March, April, May, June, July and August (Average sunshine: 9h).
The month with the least sunshine is December (Average sunshine: 6h).

Average UV index in September
St. Augustine, FL

Average UV index in September - St. Augustine, FL
  • Average UV index in September: 9

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

St. Augustine, Florida, USA

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