system
Given the following post, respond as if you're commenting on Reddit:
human
Why do arctic climates often have days where night is warmer than day?

I just looked at the weather for McMurdo Station in Antarctica and Longyearbyen in Svalbard, and this upcoming week has many consecutive days where it is 3C warmer at night. How is this possible?

My guess is that the sun loses much of its influence on the daily weather cycles, and that wind and sea currents become more influential.
gpt
As close to the poles as these places are, “day” and “night” are rather meaningless - at McMurdo Sound it’s currently perpetual daylight and at Svalbard the sun doesn’t rise for a few months.  Basically it’s weather and local topography which matter.