The hottest month in Willemstad is September when the average maximum temperature is 32°, average temperature is 29° and average minimum temperature is 27°.
The coolest month in Willemstad is January when the average maximum temperature is 29°, average temperature is 27° and average minimum temperature is 24°.
The longest days in Willemstad are in June, with an average of 12.8 hours of daylight per day. December has the shortest days with an average of 11.4 hours of daylight per day.
The sunniest days in Willemstad are in February which has the most hours of sunshine per day with an average of 8.2 hours of sunshine per day, making it a sunny month with few clouds. May has the least sunshine with an average of 6.3 hours of sunshine per day, making it a quite sunny month with some cloud cover.
The ultraviolet index is the highest in April when it reaches 14.6 and lowest in December when it reaches 9.7.
An ultraviolet index reading above 11 indicates an extreme risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 10 minutes. Take all precautions because unprotected skin and eyes can burn in minutes. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in Willemstad are found in September when they peak at 28° and lowest in April when they dip to 26°.
The sea is best for swimming between August and December when the temperature is above 27° which is very warm and ideal for relaxing and swimming for the whole day.
The wettest month in Willemstad is November with 3cm of rain and the most days of rain with 14.2 days with some rain, a slightly wet time to visit the beach.
The driest month in Willemstad is March with 0cm of rain and April has the fewest days of rain with 3.4 days with some rain, a very dry time to visit the beach.
The most humid month in Willemstad is September with a dew point (an indicator of humidity) of 26° which is very uncomfortable and fairly oppressive unless you are on a beach. At night you would most likely require airconditioning.
The least humid month in Willemstad is February with a dew point of 24° which is very humid and quite uncomfortable for most unless you are on a beach. At night you would most likely require a fan.
The most windy month in Willemstad is May when the average maximum windspeed is 31kmh and the average wind speed is 19kmh.
The least windy month in Willemstad is October when the average maximum windspeed is 25kmh and the average wind speed is 15kmh.