Miami Weather in September

September's weather is the wettest of the year for Miami, Florida. Even so, while few days are entirely clear of clouds, the city still enjoys mainly sunny skies.

This page gives detailed information on the typical September temperature, precipitation, sun, humidity, wind and storms for Miami. The numbers here are historical averages based on climate data gathered at the Miami International Airport, located five miles west of downtown Miami.

Temperature Weather iconTemperature

89 °F September average high 32 °C
77 °F September average low 25 °C
15 days 90 °F max. or more (32 °C)
0 days 70 °F min. or less (21 °C)

Typically every September day at Miami has a temperature of at least 80 degrees Fahrenheit (27 degrees Celsius). Temperatures above 100 °F (38 °C) are not expected here during this month.

Once a decade the thermometer does dip to 70 °F (21 °C) or below in September.

Rainy Weather iconRain

10.2 in total precipitation 260 mm
18 days of rain

Half the time, Miami receives 7.2 to 12.6 inches (183 to 319 mm) of rainfall in September. One in four years has drier weather, while another one in four is wetter.

Sunny Weather iconSun

70 % sunshine
2 days clear skies

The sun's rays reach the ground in Miami during 70 percent of daylight hours on average in September, for a total of 258 hours in the month. Typically on 2 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in September at Miami lasts for 12 hours and 17 minutes a day on average. The longest day of the month is the 1st with 12 hours and 39 minutes of daylight. By the end of the month, the days have shortened to 11:55 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humid Weather iconHumidity

78 % September average humidity

September is Miami's most humid month. The relative humidity this month usually peaks at 88 percent in the morning then drops to 66 percent by early afternoon.

Local Time1 am4 am7 am10 am1 pm4 pm7 pm10 pm
Humidity % 85 88 88 71 66 69 76 81

Windy Weather iconWind

8.1 mph September wind speed average 13.0 kph

September is less windy than most other months in Miami.

Stormy Weather iconStorms

6 days rainfall of 0.5 inches (13 mm) or more
11 days with thunderstorms in September
14 % chance a named storm approaches

There's a 8 percent probability that a hurricane will approach within 100 miles (165 km) of Miami during September. The chance of a major category 3 to 5 hurricane reaching the area is three percent.


The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals. The named storm probabilities come from the Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division.

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