When time-series data is plotted as a normal x-y plot with the time variable along the x-axis it is difficult to identify seasonality or other factors that may influence the data.

Florence Nightingale used a form of radial polar plots to display data from the Crimean War that demonstrated the death rate among soldiers could be reduced by better hygiene practices. Plotting the monthly numbers of deaths using this radial form demonstrates the variability during the year.

Based on the graphic displayed below, it is likely that approximately 836,000 Americans, at a minimum, prematurely died in 2020 & 2021, primarily due to the effects of COVID-19. This rough estimate is an extrapolation derived from California Department of Health and Human Services’ 2020-2021 Provisional Deaths by Month Statewide as of 11-29-2021.  The state’s aggregate provisional deaths by month for 2020 and 2021 as well as the state’s total deaths by year for the three prior years were overlaid on a polar coordinate grid by month to approximate a Nightingale rose chart. The approximate area between the solid red and black outlined ‘drop’ and ‘hook’ and the ‘rough circles’ translates into about 103,000 excess deaths in California for 2020 & 2021 combined to date during the pandemic period. Based on California’s proportion of the national population, this returns 836,000 as a rough low-ball estimate for total U.S. ‘excess deaths’ for 2020 & 2021 combined to date. (See this link for a discussion of this concept. The estimate is framed as low-end because California mitigations are assumed to be superior to U.S. average mitigations.)

The dark solid line in the upper right quadrant of the ‘target’ shows the steep decline in overall deaths in California from January to June 2021 (which was probably due to the introduction of COVID-19 vaccinations) and an uptick from July to September 2021 probably due to the Delta variant and complacency. The Omicron variant is a new factor beginning late November 2021.