The climate of Rovaniemi, the capital of the Lapland province, is cold continental, with freezing winters and mild summers.
The city is located just south of the Polar Circle, but due to atmospheric refraction, one can observe the sun at midnight from 7 June to 6 July. Furthermore, the white nights, when the sun sets but it is not completely dark even at midnight, occur from April 21st to August 23rd. In December, you can see the sun on the horizon for just over two hours. To observe the polar night, in which the sun does not rise, it is necessary to go further north of about 100 km (60 mi), for example, in Sodankylä, on the days of the winter solstice (December 21st).
The average temperature of the coldest month (January) is of -13.4 °C (8 °F), that of the warmest month (July) is of 15 °C (59 °F). In January 1999, the temperature dropped to -47.5 °C (-53.5 °F), while in July 2018, it reached 32 °C (89.5 °F). Here are the average temperatures.

Precipitation amounts to 580 millimeters (22.8 inches) per year: so, it is at an intermediate level. It ranges from 30 mm (1.2 in) in the driest month (April) to 70 mm (2.8 in) in the wettest ones (July, August). Here is the average precipitation.

On average, there are around 1,550 sunshine hours per year. Here are the average sunshine hours per day.

Best Time

The best time to visit Rovaniemi is the summer, from June to August, since it is the mildest season. However, you must take into account some rainy days and a bit of cold at night.