57 Cold Weather Health Statistics: Mortality, Temperature and Outcomes

Cold weather health statistics measure several different outcomes: deaths coded as cold-related, temperature-attributable mortality, excess winter deaths, and short-term cardiovascular or respiratory associations. The figures below identify the population, geography, period, temperature definition and measurement type so these measures are not treated as interchangeable.

Key Cold Weather Health Statistics

The most broadly useful figures include:

  • 40,079 deaths in the United States had cold recorded as an underlying or contributing cause during 1999–2022.
  • Cold-related deaths represented 0.06% of 63,550,429 U.S. deaths during 1999–2022.
  • The U.S. age-adjusted cold-related mortality rate rose from 0.44 per 100,000 people in 1999 to 0.92 per 100,000 in 2022.
  • U.S. cold-related mortality increased 12.1% annually from 2017 through 2022.
  • Adults aged 75 or older had a 2022 U.S. cold-related mortality rate of 4.23 per 100,000.
  • American Indian or Alaska Native people had a 2022 U.S. cold-related rate of 6.26 per 100,000.
  • The U.S. Midwest had the highest listed regional cold-related rate in 2022 at 1.41 per 100,000.
  • The CDC recorded 1,024 U.S. deaths attributed to excessive cold or hypothermia in 2023.
  • January accounted for 19.9% of U.S. excessive-cold or hypothermia deaths in 2023.
  • Cold days below the 2.5th temperature percentile accounted for 9.1 excess deaths per 1,000 cardiovascular deaths across 567 cities in 27 countries.
  • The same international analysis estimated 12.8 excess deaths per 1,000 heart-failure deaths during cold below the 2.5th percentile.
  • A 26-study meta-analysis found a 5.5% higher cardiovascular mortality risk with cold exposure.
  • A 159-study review estimated a 1.6% increase in cardiovascular mortality per 1°C temperature decrease.
  • In Scotland below 11°C, each 1°C drop in daytime mean temperature was associated with a 4.8% increase in respiratory mortality over the following month.
  • In Ontario, each 5°C cold-season decrease was associated with a 5.8% increase in ischemic-heart-disease deaths over lag days 0–6.
  • Ontario researchers estimated about 7 temperature-related excess deaths per day during cold seasons from 1996–2010.
  • In southeast England, a 1°C one-day fall in the 0–15°C range was associated with 24.7 excess all-cause deaths per million people aged 50 or older.
  • WHO estimated 38,200 excess winter deaths annually across 11 European countries were related to low indoor temperatures.

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The peer-reviewed study Cold-Related Deaths in the US counted 40,079 U.S. deaths during 1999–2022 in which cold was recorded as an underlying or contributing cause. These death-certificate data used ICD-10 codes X31, T68 or T69, and the study cautions that this coding can underestimate cold-related mortality. Cold-Related Deaths in the US

Cold was not necessarily the sole cause in this measure. The 40,079 deaths represented 0.06% of 63,550,429 U.S. deaths during the same period.

U.S. measure Result Period and definition
Age-adjusted cold-related mortality rate 0.44 to 0.92 per 100,000 1999 to 2022; rates age-adjusted to the 2000 U.S. Census population
Change in cold-related mortality rate 109% increase 1999–2022
Overall annual percentage change 3.4% per year 1999–2022; Joinpoint estimate, 95% CI 2.4%–4.3%
Annual change 1.0%, not statistically significant 1999–2017; 95% CI −0.9% to 2.2%, P=.20
Annual change 12.1% per year 2017–2022; 95% CI 6.3%–27.1%

When cold was restricted to the underlying cause of death, the annual increase from 2016–2022 was 9.1% in a sensitivity analysis, with a 95% CI of 3.1%–27.9%. These are observed mortality trends and regression estimates, not forecasts of individual risk.

Cold Weather Mortality by Age, Sex, Race and Region

The 2022 U.S. rates varied substantially by age. Adults aged 75 or older had the highest listed age-group rate, while people aged 24 or younger had the lowest.

U.S. population group 2022 cold-related rate per 100,000 95% CI
Age 24 or younger 0.05 0.04–0.06
Age 25–44 0.66 0.61–0.72
Age 45–74 1.54 1.47–1.61
Age 75 or older 4.23 3.97–4.49
Males 1.34 1.28–1.39
Females 0.51 0.48–0.54

The 45–74 age group also had the largest estimated annual increase during 1999–2022, at 4.8% per year, with a 95% CI of 3.7%–5.6%.

Race and ethnicity were recorded on death certificates. In 2022, the American Indian or Alaska Native rate was 6.26 per 100,000, with a 95% CI of 5.25–7.27; the Black rate was 1.50, and the Hispanic rate was 0.51 per 100,000. Cold-Related Deaths in the US

The Midwest had the highest U.S. regional rate in 2022 at 1.41 per 100,000 (95% CI 1.32–1.49). Its estimated annual increase during 1999–2022 was 4.3%, with a 95% CI of 2.8%–5.6%.

Monthly Excessive-Cold and Hypothermia Deaths

The CDC’s 2023 measure is narrower than the long-term study: it uses underlying-cause ICD-10 X31 and multiple-cause T68 coding. The CDC recorded 1,024 U.S. deaths attributed to excessive cold or hypothermia in 2023, and the monthly percentages below describe that total. QuickStats: Percentage Distribution of Deaths Attributed to Excessive Cold or Hypothermia, by Month — United States, 2023

Month in 2023 Share of annual CDC-coded deaths
January 19.9%
February 16.8%
March 14.2%
April 5.7%
May 2.7%
June 1.9%
July 1.5%
August 1.4%
September 2.1%
October 5.0%
November 11.9%
December 16.7%

January had the largest monthly share at 19.9%, followed by February at 16.8%, March at 14.2% and December at 16.7%. This monthly distribution should not be combined directly with the broader JAMA definition, which also includes T69 and allows cold as an underlying or contributing cause.

Cold Temperature Cardiovascular Statistics

An analysis covering overlapping city periods from 1979–2019 examined 567 cities in 27 countries. Relative to each location’s minimum-mortality temperature, cold days below the 2.5th temperature percentile accounted for 9.1 excess deaths per 1,000 cardiovascular deaths and 12.8 excess deaths per 1,000 heart-failure deaths.

The pooled observational estimates had 95% eCIs of 8.9–9.2 and 12.2–13.1, respectively. Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality: Results From 27 Countries

Review or analysis Cold exposure measure Cardiovascular outcome
26-study meta-analysis, studies published 2000–2015 Cold exposure 5.5% higher mortality risk; RR 1.055, 95% CI 1.050–1.060
159-study systematic review Each 1°C decrease 1.6% higher mortality; RR 1.016, 95% CI 1.015–1.018
159-study systematic review Each 1°C decrease 1.2% higher morbidity; RR 1.012, 95% CI 1.010–1.014

The 26-study result is a pooled short-term association, while the 159-study estimates pool observational and other original research. Neither should be read as an individual prognosis. A systematic review and meta-analysis of cold exposure and cardiovascular disease outcomes

Cold Weather Respiratory and All-Cause Mortality Statistics

In Scotland, when daytime mean temperature was below 11°C, a 1°C drop was associated with higher mortality over the following month. The estimates were 2.9% for all-cause mortality, 3.4% for cardiovascular mortality, 4.8% for respiratory mortality and 1.7% for other-cause mortality. The lagged effect of cold temperature and wind chill on cardiorespiratory mortality in Scotland

Ontario data from 27 selected census divisions covered cold seasons from 1996–2010 and used lag days 0–6. Each 5°C cold-season decrease was associated with a 3.0% increase in nonaccidental deaths, a 4.1% increase in cardiovascular deaths and a 5.8% increase in ischemic-heart-disease deaths. Assessment of the effect of cold and hot temperatures on mortality in Ontario, Canada: a population-based study

Among Ontario people younger than 65, the same 5°C decrease was associated with an 8.0% increase in cardiovascular mortality (95% CI 3.0%–13.0%). Researchers estimated that temperature changes induced about 7 excess deaths per day in Ontario during cold seasons; this was a model-based provincial estimate.

Cold Exposure Timing and International Estimates

In southeast England, including London, a 1976–1992 study of people aged 50 or older examined one-day temperature falls in the 0–15°C range. Each 1°C fall was associated with 7.3 excess ischemic-heart-disease deaths, 5.8 excess respiratory deaths and 24.7 excess all-cause deaths per million people. Early increases in ischaemic heart disease mortality dissociated from and later changes associated with respiratory mortality after cold weather in south east England

The timing differed by outcome: ischemic-heart-disease deaths peaked about 3 days after the cold peak, respiratory deaths peaked about 12 days afterward, and the all-cause mortality increase lasted approximately 40 days. These are population-level regression patterns and short-term displacement estimates, not individual forecasts.

WHO’s European indoor-cold summary estimated 38,200 excess winter deaths annually across 11 European countries, equivalent to 12.8 excess deaths per 100,000 population annually. The report says the estimate draws on several studies and that a full burden-of-disease methodology could not be applied because of missing data. Environment, Climate Change and Health: Indoor cold and mortality summary report

WHO also reported that cardiovascular conditions account for an estimated 50%–70% of excess winter deaths, while respiratory disease accounts for an estimated 15%–33%. Those ranges refer to excess winter deaths in the European evidence summarized by WHO, not to all cold-coded deaths in the United States.

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