Heat/Cold Mortality

Desired Trend


Current Trend

Baseline (2008-2012): 24.0
Current (2012-2016): 25.6

Theme Prepared


Number of heat- and cold-related deaths

Why is it Important?

Extreme cold and extreme heat are the most common causes of weather-related deaths in the United States.1 Extreme heat can cause life-threatening illnesses such as heat exhaustion or heat stroke and can increase the risk of suffering a heart attack. Extreme cold can result in hypothermia and also increases the risk of heart attacks.2 Climate change is expected to increase the frequency and duration of heat waves, which will increase the risk of heat-related deaths. Conversely, climate change is expected to reduce the number of cold-related deaths, but not enough to offset the expected increase in heat-related deaths.3 Both heat- and cold-related deaths are preventable through proactive efforts such as public notification systems and public shelters. This indicator provides a conservative estimate of the number of heat- and cold-related deaths in the St. Louis region. Only deaths that are classified by medical professionals as related to excessive heat or excessive cold are included in the measure.

How are we Doing?

Between 2012 and 2016, there was an annual average of 25.6 deaths related to excessive heat or cold. This is a slight increase from the baseline period. From 2008 to 2012, there was an average of 24.0 heat- and cold-related deaths annually. The five-year rolling annual average is used for this metric because there is a lot of fluctuation from year to year.

Looking over a longer period of time, this performance measure is trending upward, opposite of the desired trend. About 10 years ago, between 2002 and 2006, the average heat- and cold- mortality was 19.6 deaths per year. The graph shows the annual number of deaths as well as the five year average, showing that, on average, the number deaths is increasing.

Over the 2012-2016 time period, the St. Louis region ranked 4th among the 50 most populous metropolitan regions, with a higher rate of heat- and cold-related deaths per capita than most of the other peer regions. There was an average of 0.9 heat- and cold-related deaths per 100,000 population in the St. Louis region compared to 0.7 deaths per 100,000 population for the United States.

Heat and Cold Deaths

Geographic Level

St. Louis Metropolitan Statistical Area (MSA). View map.


1Goklany, Indur, Death and Death Rates Due to Extreme Weather Events: Global and U.S. Trends, 1900-2006, November 2007; accessed on 12 February 2014 at http://www.csccc.info/reports/report_23.pdf

2American heart Association, Cold Weather and Cardiovascular Disease, 4 December 2013; accessed on 15 February 2014 at http://www.heart.org/HEARTORG/Conditions/More/MyHeartandStrokeNews/Cold-Weather-and-Cardiovascular-Disease_UCM_315615_Article.jsp

3U.S. Environmental Protection Agency, Climate Change Indicators in the United States, 13 September 2013; accessed on 8 January 2014 at http://www.epa.gov/climatechange/science/indicators/society-eco/heat-deaths.html

4The heat- and cold-related deaths included in this indicator are those that were classified as having “excessive heat” or “excessive cold” as an underlying or contributing cause of death on the death certificate. Data for 2004 is not available due to the low number of heat- and cold-related deaths that year. 

Data Sources

Wonder Multiple Cause of Death Database, Centers for Disease Control and Prevention