It's not as cold as you think in Tromsø in winter: The average temperature hovers around -4C/25F, and the temperature very rarely drops below -10C/14F, which is very inviting for outdoor activities. The light conditions, however, are on the extreme side, with a seven weeks' absence of sun around mid winter, although days are back to normal by March. Winter is the time for the most beautiful of all sights, the fragile dance of the Northern Lights.