Biscayne National Park weather in September
September in Biscayne National Park: sweltering, soaked, with clean air — a fair time to visit.
#11 of 12 months in Biscayne National Park · #531 of 604 destinations to visit in September · comfort 57/100 (tier D)
Updated June 2026 · climate normals from ERA5 reanalysis
Biscayne National Park climate normals — September
| Daytime high | 30°C / 86°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 26°C / 78°F | |
| Feels like (high) | 35°C / 95°F | |
| Rainfall | 187 mm / 7.3 in | ⛈ soaked |
| Rainy days | 21 days | |
| Humidity | 82% | 💦 very humid |
| Dew point | 24°C / 75°F | |
| Sunshine | 9.8 h/day | |
| Daylight | 12.3 h | |
| Wind | 18 km/h / 11 mph | |
| Air quality (US AQI) | 32 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Biscayne National Park?
Loading map…
Biscayne National Park in September — FAQ
- Is September a good time to visit Biscayne National Park?
- September in Biscayne National Park: sweltering, soaked, with clean air — a fair time to visit. It ranks #11 of 12 months for Biscayne National Park on SeasonMap's comfort score (57/100).
- What is the weather like in Biscayne National Park in September?
- In September, Biscayne National Park averages a daily high of 30°C and a low of 25.7°C, with about 186.6 mm of rain over roughly 21.4 rainy days.
- What is the air quality in Biscayne National Park in September?
- Biscayne National Park has a mean US Air Quality Index of about 32 in September.