Taking the local weather in Sandnessjøen into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually July and August, with an average temperature of 12°C, while the coldest months are February and January, with an average of 0°C. The rainiest months in Sandnessjøen are September, October, March and December, with each month seeing an average of 193 mm of rainfall.