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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors and will be provided to the relevant journal upon publication.