The hottest month in Glenan Islands is July when the average maximum temperature is 21°, average temperature is 17° and average minimum temperature is 14°.
The coolest month in Glenan Islands is February when the average maximum temperature is 10°, average temperature is 7° and average minimum temperature is 4°.
The longest days in Glenan Islands are in June, with an average of 16 hours of daylight per day. December has the shortest days with an average of 8.4 hours of daylight per day.
The sunniest days in Glenan Islands are in June which has the most hours of sunshine per day with an average of 8.5 hours of sunshine per day, making it a sunny month with few clouds. December has the least sunshine with an average of 2 hours of sunshine per day, making it not a particularly sunny month.
The ultraviolet index is the highest in July when it reaches 8.3 and lowest in December when it reaches 0.8.
An ultraviolet index reading of 8 to 10 indicates a very high risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 15 minutes. Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly. 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 Glenan Islands are found in August when they peak at 18° and lowest in February when they dip to 11°.
The sea is best for swimming between June and December when the temperature is above 14° which is cold for swimming, a full wet suit is required to spend any length of time in the sea.
The wettest month in Glenan Islands is February with 1.7cm of rain and January has the most days of rain with 19.9 days with some rain, a wet time to visit the beach.
The driest month in Glenan Islands is September with 0cm of rain and the least days of rain with 10.6 days with some rain, a slightly wet time to visit the beach.
The most humid month in Glenan Islands is August with a dew point (an indicator of humidity) of 16° which is comfortable for everyone.
The least humid month in Glenan Islands is February with a dew point of 6° which is a bit dry for some.
The most windy month in Glenan Islands is January when the average maximum windspeed is 27kmh and the average wind speed is 15kmh.
The least windy month in Glenan Islands is September when the average maximum windspeed is 21kmh and the average wind speed is 11kmh.