Climate on the Riau Islands
(Indonesia)

The number of hours of sunshine refers to the time when the sun is actually visible. That is, without any obstruction of visibility by clouds, fog or mountains. With 7 hours per day, February is the sunniest month in archipelago Riau Islands. In December, the sun shines the least.

A rain day is a day on which at least 0.1 mm precipitation (=0.1 liter) per square meter falls. This can be rain, snow, hail or even dew. So it does not have to rain the whole day. With 17 rain days, November offers the most rain days, while February has the fewest.

The amount of precipitation is measured in millimeters per square meter. Thus, at two mm/day, two liters of water fall on one square meter within 24 hours. With only 3.9 mm, the least amount of rain falls in February. November, on the other hand, has the most rain.