He believes that winter-based downturns in mood in the darkest months may be a reaction to that history: “There is some evidence that suggests that in the more northern latitudes there is more seasonal depression.”

Source: https://www.minnpost.com/mental-health-addiction/2023/12/hibernation-season-for-many-winter-presents-a-mental-health-challenge/

Only about one-third of the plant species studied, including holly, wild olives, and ivy, produce fruit in the spring when the birds are heading north—a time that would help the species move to cooler latitudes.

Source: https://www.theatlantic.com/science/archive/2023/11/plant-seed-dispersing-climate-change/675898/?utm_source=feed

That is basically what causes the greenish ghostly lights in the sky, though they're not often seen in latitudes this far south.

Source: https://wibx950.com/ixp/705/p/northern-lights-new-york/

The team showed that correlations between Covid-19 metrics (new cases and deaths, total cases and deaths) and temperature and latitude strengthened during cooler months and at higher latitudes.

Source: https://www.canindia.com/study-traces-covids-seasonal-behaviour-to-genetics-global-change/

Usually a strong jet stream confines Arctic air to the north, stabilized by a big difference in temperature between low and high latitudes.

Source: https://www.vox.com/climate/23780315/south-heat-wave-jet-stream-louisiana-texas-climate-el-nino