The hottest month in Okinawa is July when the average maximum temperature is 31°, average temperature is 29° and average minimum temperature is 26°.
The coolest month in Okinawa is January when the average maximum temperature is 19°, average temperature is 16° and average minimum temperature is 12°.
The longest days in Okinawa are in June, with an average of 13.8 hours of daylight per day. December has the shortest days with an average of 10.5 hours of daylight per day.
The sunniest days in Okinawa are in June which has the most hours of sunshine per day with an average of 8.8 hours of sunshine per day, making it a sunny month with few clouds. December has the least sunshine with an average of 5.2 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in July when it reaches 12.7 and lowest in December when it reaches 5.3.
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 Okinawa are found in July when they peak at 29° and lowest in February when they dip to 22°.
The sea is best for swimming between June and December when the temperature is above 25° which is warm and pleasant for relaxing and swimming for long periods.
The wettest month in Okinawa is June with 34.6cm of rain and January has the most days of rain with 22 days with some rain, a very wet time to visit the beach.
The driest month in Okinawa is January with 9.7cm of rain and July has the fewest days of rain with 14.6 days with some rain, a slightly wet time to visit the beach.
The most humid month in Okinawa is July with a dew point (an indicator of humidity) of 27° which is extremely humid and uncomfortable unless you are on a beach. At night you would most likely require airconditioning.
The least humid month in Okinawa is January with a dew point of 14° which is comfortable for everyone.
The most windy month in Okinawa is October when the average maximum windspeed is 31kmh and the average wind speed is 18kmh.
The least windy month in Okinawa is January when the average maximum windspeed is 27kmh and the average wind speed is 16kmh.