U.S. Lightning Deaths since the Year 1000

The present study estimates the total number of lightning fatalities since the year 1000 within the continental United States. The book 1491 by Charles C. Mann refers to estimates of past populations in the Americas. Although the number of people is not well known during the earlier years of this period, lower and upper population bounds can be estimated from various sources. In addition, lower and upper bounds of lightning fatality rates can be estimated based on past and present rates in the United States and elsewhere. As a result, it is instructive to develop a baseline estimate of lightning deaths after 1000, since lightning has such a strong presence in history, art, myths, stories, and folklore of all people through the ages.

Records have been kept for lightning fatalities in the U.S. during the last few decades with ever-increasing accuracy. The average number of deaths during the last decade from 2008-2017 is 28 per year; the corresponding population-weighted rate is 0.1 deaths /million people/year. Going back to 1959 when the National Weather Service publication Storm Data began, there have been 4,136 reported deaths for an annual average of 70 per year at a rate of 0.3 deaths/million people/year. Summaries of fatalities reaching back to 1900 in the U.S. show much larger death totals in the early part of the 20^th century that reached as high as 476 deaths per year, and individual years had rates up to 6.0 deaths/million people/year.

The developed countries of Western Europe, Japan, and Australia also had annual fatality rates as high as 3.0 in the 1800s that have reduced to a current value of 0.1. These dramatic reductions have been attributed in numerous studies to greatly improved quality of buildings including dwellings and other public buildings, a massive reduction in the number of people involved in labor-intensive outdoor agriculture, the ready availability of lightning-safe vehicles, and improved lightning education and medical care.

In contrast, some developing nations in Africa and Asia continue to have very large annual lightning fatality rates. A rate exceeding 5.0 fatalities/million people/year is common, and rates may be as high as 10.0 to 15.0 or more. These countries tend not to have lightning-safe buildings and vehicles, mechanized agriculture, and education and medical care advances that now prevail in developed countries.

The U.S. dataset since 1000 is divided into two segments. The older segment is based on controversial counts of the Native American population before 1700. A Native American population of as few as 500,000 people and a rate of 2.0 lightning deaths/million people/year results in 610 deaths from 1000 to 1700. A larger population estimate of 10 million people and a rate of 10.0 lightning deaths/million/year indicates 62,000 Native American fatalities from 1000 to 1700. It is likely that the number of Native American lightning deaths was in the thousands, but the population uncertainty precludes results that are more specific.

The more recent segment starts when the U.S. mainly non-indigenous population started rapidly growing from a census of 250,000 people in 1700. This growth was accompanied by a decrease in the Native American population due to disease and other factors after 1492. Applying a rate of 2.0 lightning deaths/million people/year to the census values results in 32,627 lightning deaths in the U.S since 1700. Applying a rate of 6.0 lightning deaths/million people/year results in 57,437 lightning deaths in the U.S. since 1700.

In summary, the smallest likely population and death rate leads to a sum of about 33,000 lightning deaths from the year 1000 through 2017 in the U.S. The largest likely population and death rate leads to a sum of about 119,000 lightning deaths from the year 1000 through 2017 in the U.S. The greatest uncertainty is in the Native American population data prior to the rapid growth of the non-indigenous population.