Key Biscayne Weather in September
September in Key Biscayne sees daytime temperatures around 31°C (88°F) and lows of 26°C (79°F) at night. Being part of the rainy season, heavy rainfall is a regular part of the day, so pack accordingly.
Rainfall in Key Biscayne in September
As part of the rainy season, Key Biscayne sees around 26 days of rain in September, with an average of 181 mm (7.1 in). The rainy season here brings regular, substantial showers. It's worth being prepared for rain on most days you're out.
Temperature in Key Biscayne in September
Temperatures in Key Biscayne in September top out at 31°C (88°F) and drop to 26°C (79°F) overnight. It's usually most comfortable outside during the morning and later in the day. With overnight lows of 26°C (79°F), evenings and nights remain warm. Light clothing and an open window or fan can help you sleep comfortably.
Sunshine in Key Biscayne in September
There are approximately 260 hours of sunshine this month, despite being the rainy season. Rain often arrives in the late afternoon or evening, keeping mornings and early afternoons sunny. Even during the wet season, it could still be a nice time to visit.
Wind Speed in Key Biscayne in September
In September, average wind speeds reach 4 m/s (8 knots), leading to light to moderate breezes. Conditions vary from day to day, with both calm and windier periods.
Average water temperature in September
The water is 28°C (82°F) this month — warm enough that getting in requires no effort at all. Good conditions for swimming, snorkeling, or just floating around.September in Key Biscayne can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Key Biscayne's climate page.
Key Biscayne Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
31°C (88°F)
Water Temperature
28°C (82°F) *
Chance of Rain
85%
Precipitation
181 mm (7.1 in)
Rainy days
26 days
Humidity
78% *
Windspeed
4 m/s (8 knots) *
Sunshine
260 hours *
Percentage Sunshine
71% *
Best Places in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in September →
perfect weather
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What to Wear in Key Biscayne in September
Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Heavy rain is guaranteed, please bring a good poncho and waterproof everything! Expect water temperatures of around 28°C (82°F), which is ideal for taking a refreshing dip. Bring swimwear and consider packing a towel for drying off. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Key Biscayne in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Key Biscayne's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Key Biscayne climate overview or explore weather in the United States of America.
