UKHSA publishes first Cold Mortality Report
Findings show that 2,544 deaths in England were associated with cold weather across 3 cold episodes recorded between November 2024 and January 2025.
The UK Health Security Agency (UKHSA) has published its first Cold Mortality Monitoring Report, providing new estimates of deaths associated with cold weather in England during winter 2024 to 2025.
Findings from the report show that 2,544 deaths were associated with cold weather across 3 cold episodes recorded between November 2024 and January 2025. The most severe episode, a 6-day period in early January, accounted for 1,630 deaths, while shorter episodes in November and early January were associated with 421 and 493 deaths respectively.
Other key findings from the report include:
- older people were most affected, with the risk rising steeply with age, especially in those aged 85 and over
- men had a higher number of cold-associated deaths (1,439) than women (1,117)
- circulatory diseases caused the highest number of cold-related deaths, with 834 deaths linked to conditions such as heart disease
- most deaths (975) happened in hospitals, although the increase in risk during cold weather was greater for people in care homes and those who died at home
The report found that mortality peaks around 5 days after cold weather and remains elevated for up to 9 days. Heart-related deaths tend to increase several days after cold exposure, while respiratory and infection-related deaths show longer delays.
To understand the health impact of cold weather, UKHSA analyses daily death registrations alongside Met Office temperature data. UKHSA used a statistical model that shows how the risk of death increases as temperatures fall, and how these effects can build up over several days. This helps us to estimate the number of deaths linked to specific cold spells, rather than relying on death certificates, which do not record ‘cold’ as a cause.
These estimates form a key part of wider winter health surveillance. They sit alongside monitoring of flu, COVID-19, RSV, norovirus and other seasonal pressures, helping to ensure that Cold Weather Alerts and preparedness planning reflect the real health risks faced by vulnerable groups.
UKHSA’s episode‑based method provides an up‑to‑date picture of how recent cold weather has affected people’s health under current population and health system pressures, complementing the Office for National Statistics’ (ONS) long‑term analyses that estimate the average impact of cold weather over many decades. Because UKHSA focuses on specific recent winters and the ONS looks at long‑term trends, the figures are not directly comparable, but together they give a fuller picture of how cold weather affects health in England.
Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, said:
Cold weather remains a serious and preventable risk to public health.
This report provides important new evidence on how cold affects mortality, helping to ensure that Cold Weather Alerts and preparedness measures are grounded in evidence of health impact. The findings suggest that even short periods of cold can lead to significant increases in mortality, often days or weeks after the temperature drops.
Understanding who is most affected and how these risks are changing helps us better target winter preparedness, support vulnerable groups, and ensure that cold weather alerts reflect real health impacts, not just weather conditions.
Population groups most at risk from cold weather include:
- people aged 65 years and over
- people with cardiovascular or respiratory conditions
- people with dementia
- people living in poorly insulated homes or experiencing fuel poverty
When comparing recent winters with the previous 5-year period, the findings suggest people may now be more vulnerable to cold, with the risk of death rising more sharply as temperatures drop. This is likely to be the result of a combination of factors including the ageing population and burden of disease.
While further research over longer time periods is needed to confirm whether this represents a sustained shift, these findings suggest that vulnerability to cold may be increasing even if average winter temperatures are not becoming colder. Factors such as home insulation and heating, access to healthcare, vaccination uptake, and awareness of cold weather risks can all influence cold-associated mortality.
The full Cold Mortality Monitoring Report is published. This report complements the annual heat mortality monitoring reports published by UKHSA, and both contribute to the evidence base underpinning the Adverse Weather and Health Plan for England.