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# Why Does COVID-19 Target the Northern Hemisphere?

A graph of death rates by latitude is revealing

Like the grim reaper, COVID-19 is menacing the world, bring economies to a standstill and pushing the “free countries” to adopt the tactics of authoritarian regimes. Originally promised to last only a few weeks, the lockdowns are drawing into potentially months. A further concern has arisen; there may be multiple waves, as happened with the Spanish flu, where the second and third waves were even more deadly. If COVID-19 is a pandemic, there seems to be no escape.

But, is it really a global pandemic? If you’ve been watching the news, you might notice that some areas of the world are oddly absent from the reporting. Wouldn’t we expect the disease to rip through the most densely packed and least developed countries? Instead, the virus has mostly shut down some of the most advanced nations, which in turn only represent a small portion of the world’s population. How can we explain this oddity? Well, let’s look at a graph of covid-19 death rates by latitude:

The graph above was generated from data I took from the Google front page statistics for coronavirus cases and deaths on April 4. The materials used in creating the graph are here. Countries were matched to their latitudes and countries with fewer than 500 cases were removed from the dataset. The result shows a best fit quadratic curve. It turns out, the quadratic curve has a much greater statistical significance than a normal linear regression.

First of all, COVID-19 clearly does not attack the globe uniformly by latitude. The second standout feature is that it targets the northern hemisphere. This is bizarre. How can a disease’s spread be affected by hemisphere, let alone latitude? That is not a statistical fluke because the graph comprises 198 different countries and the best fit quadratic curve parameters have statistical significance scores of 0.12, 0.07 and 0.0000016 for the x^2, x and c components respectively.

What was the big difference between the hemispheres when the data was pulled? Due to the northern hemisphere bias of much of the internet, many information seekers will overlook the fact that it is nearing the end of summer in the southern hemisphere.

How could that affect the COVID-19 death rates? The disease virus is a variant within the same group as cold viruses and the cold virus is destroyed by heat. Is COVID-19 vulnerable to heat? It is worth asking whether that explains the lower mortality rate near the equator and in the southern hemisphere. At any rate, given how little we know about COVID-19, we should acknowledge the unknown unknowns before drawing firm conclusions on the subject.