In 1990 the Swedish public service TV introduced the so-called sun league table, where they measured the amount of sunshine hours on different places in Sweden. Ever since, Gotland has been the one to beat and is considered to be the sunniest place in the country with over 1900 sunshine hours per year.
The competition runs for 8 weeks every summer and measures the time when direct radiation is exceeding 120 watts per square meter. The reason why Gotland so often is topping the table is the favorable location in the Baltic Sea. This gives us relatively little cumulus and we therefore have many hours of sun per day. Obviously it rains on Gotland as well but there are often shorter showers and even in a “bad day” we can get several hours of sunlight.