The hottest month in Amami Oshima Island is August when the average maximum temperature is 31°, average temperature is 29° and average minimum temperature is 27°.
The coolest month in Amami Oshima Island is January when the average maximum temperature is 17°, average temperature is 15° and average minimum temperature is 13°.
The longest days in Amami Oshima Island are in June, with an average of 13.9 hours of daylight per day. December has the shortest days with an average of 10.3 hours of daylight per day.
The sunniest days in Amami Oshima Island are in May which has the most hours of sunshine per day with an average of 9.4 hours of sunshine per day, making it a sunny month with few clouds. December has the least sunshine with an average of 5.6 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 12.4 and lowest in December when it reaches 4.6.
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 Amami Oshima Island are found in July when they peak at 29° and lowest in March when they dip to 21°.
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 most humid month in Amami Oshima Island is July with a dew point (an indicator of humidity) of 25° 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 Amami Oshima Island is January with a dew point of 10° which is very comfortable.
The most windy month in Amami Oshima Island is October when the average maximum windspeed is 31kmh and the average wind speed is 23kmh.
The least windy month in Amami Oshima Island is July when the average maximum windspeed is 25kmh and the average wind speed is 18kmh.