Why is it so cold in Harbin?

Harbin has a long winter time and short direct sunlight time all year round. Although spring has arrived in solar terms, in fact, there is no sign of spring yet. It seems that the average temperature for ten consecutive days is above 10 degrees, so it can be judged that spring has arrived. So far, not to mention that there is no continuous weather above 10 degrees in Harbin, so it is still the end of winter.

The heating date in Harbin will be April 15, which means it will be cold for a while. In addition, when the snow melts, the temperature will inevitably drop again, so keep warm. Isn't there a saying that spring is chilly and autumn is crisp?