Gods Lockdown: the effect of the April 2022 Colorado low blizzard on SARS-Cov-2 transmission in the midwest United States

Background Lockdowns have been used as a primary non-pharmaceutical intervention to stop transmission of COVID19. There are many issues with interpreting the causal effects of most of these intentional, policy driven interventions. We leverage a natural experiment to avoid many of these issues to better understand the direct effects of lockdown like conditions on COVID19 transmission. Methods We exploit a blizzard that interrupted activity across several midwestern states in April 2022. This blizzard broke records for snowfall and caused economic disruption. We leverage this to create control and treatment counties that were more or less affected by the snowfall. We demonstrate effects using event studies comparing these treatment and control counties. Results We find that mobility within treatment counties was severely curtailed as a result of the blizzard relative to control counties. We find cumulative declines in the number of COVID19 cases per country by 400 and cumulative declines in COVID19 deaths by 1 per county over the 30 days after the storm. We find declines in by one per hospitalization due to COVID19. Conclusions The April 2022 blizzard caused disruption in activity across the midwest United States akin to a lockdown. It reduced the number of COVID19 cases, deaths, and hospitalizations in treatment counties relative to control counties suggesting that similar policies do limit transmissions of SARS-Cov-2.