The hottest month in Yaeyama Islands is July when the average maximum temperature is 32°, average temperature is 29° and average minimum temperature is 27°.
The coolest month in Yaeyama Islands is January when the average maximum temperature is 21°, average temperature is 18° and average minimum temperature is 17°.
The longest days in Yaeyama Islands are in June, with an average of 13.6 hours of daylight per day. December has the shortest days with an average of 10.6 hours of daylight per day.
The sunniest days in Yaeyama Islands are in May which has the most hours of sunshine per day with an average of 6.4 hours of sunshine per day, making it a quite sunny month with some cloud cover. December has the least sunshine with an average of 3.6 hours of sunshine per day, making it not a particularly sunny month.
The ultraviolet index is the highest in July when it reaches 12.9 and lowest in December when it reaches 5.9.
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 Yaeyama Islands are found in July when they peak at 29° and lowest in March when they dip to 23°.
The sea is best for swimming between May and December when the temperature is above 26° which is very warm and ideal for relaxing and swimming for the whole day.
The wettest month in Yaeyama Islands is June with 3.6cm of rain and January has the most days of rain with 20.1 days with some rain, a very wet time to visit the beach.
The driest month in Yaeyama Islands is January with 0.6cm of rain and July has the fewest days of rain with 11.5 days with some rain, a slightly wet time to visit the beach.
The most humid month in Yaeyama Islands is August with a dew point (an indicator of humidity) of 26° 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 Yaeyama Islands is January with a dew point of 15° which is comfortable for everyone.
The most windy month in Yaeyama Islands is October when the average maximum windspeed is 30kmh and the average wind speed is 21kmh.
The least windy month in Yaeyama Islands is May when the average maximum windspeed is 23kmh and the average wind speed is 15kmh.