Willemstad weather in September
September in Willemstad: hot, a little rain, with clean air — an excellent time to visit.
#4 of 12 months in Willemstad · #400 of 897 destinations to visit in September · comfort 85/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Traveller notes on Willemstad in September
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Willemstad climate normals — September
| Daytime high | 30°C / 85°F | 🥵 hot |
|---|---|---|
| Nighttime low | 28°C / 82°F | |
| Rainfall | 48 mm / 1.9 in | 🌦 some rain |
| Rainy days | 8 days | |
| Humidity | 78% | 💦 very humid |
| Dew point | 25°C / 76°F | |
| Sunshine | 10.9 h/day | |
| Daylight | 12.2 h | |
| Wind | 31 km/h / 19 mph | |
| Air quality (US AQI) | 44 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Willemstad in September — FAQ
- Is September a good time to visit Willemstad?
- September in Willemstad: hot, a little rain, with clean air — an excellent time to visit. It ranks #4 of 12 months for Willemstad on SeasonMap's comfort score (85/100).
- What is the weather like in Willemstad in September?
- In September, Willemstad averages a daily high of 29.7°C and a low of 27.6°C, with about 47.7 mm of rain over roughly 8.4 rainy days.
- What is the air quality in Willemstad in September?
- Willemstad has a mean US Air Quality Index of about 44 in September.