Jan Mayen has an arctic maritime climate, which causes frequent storms and persistent fog. Though the island is small, the weather can vary greatly from one place to another; travelers on one side of the island might be treated with bright sunshine, while at the same time others will be experiencing impenetrable fog on the other. When the fog clears, however, the views of white-capped Beerenberg are stunning. A day may start out perfectly calm but end in a gale, and it is this wind that makes the average winter day’s 23° F feel like an icy -15°. Those enjoying a Jan Mayen tour in the summer will notice that the Southern Lagoon dries out, leaving a dry, sandy plain, making the eastern side of the island subject to dust and sandstorms.
The average temperature on Jan Mayen is 30° F, with very little fluctuation between summer and winter. In February and March, the coldest months, temperatures average around 20° F. In July and August they stay around 40° F, though the island has experienced temperatures as warm as 64° F and as cold as –22°. The island receives very little precipitation, averaging about 27 inches per year. If you travel in September and October you will see the most moisture, with about three inches falling per month. April and May are the drier months, with only an inch and a half of rain or snow.