Research and analysis

HPR volume 20 issue 2: news (26 February 2026)

Updated 26 February 2026

Cold mortality monitoring report: winter 2024 to 2025

Estimates of the number of cold-associated deaths that occurred in England as a result of three ‘cold weather episodes’ during the winter of 2024/25 are presented in the first of a new series of UKHSA statistical reports on cold mortality monitoring.

Key findings of the report are that:

• an estimated 2,544 cold-associated deaths occurred across 3 cold weather episodes (95% CI: 1,965 to 3,131) in 2024/25

• the strongest cold-mortality risk relationship was observed in adults aged 85 years and over, for whom the mortality risk vs temperature gradient was steepest

• where cold-associated mortality risk was broken by place of death (care homes, hospitals, people’s own homes and hospices), the cold-mortality risk relationship was most strongly observed in care homes and own homes

In the statistical analysis of mortality data underpinning the report, cold-associated deaths were defined as deaths attributable to exposure to cold temperatures over and above the number expected without cold weather; the analysis captured both immediate effects (deaths occurring during a cold weather episode) and delayed effects (those occurring after).

In contrast to the statistical model used for the Agency’s annual heat-associated mortality report, which considers observed daily deaths in a single summer, the model used for cold mortality monitoring considers deaths over 5 recent winters; this takes account of the longer observed delays between ‘cause and effect’ for cold-related mortality.

The strongest relationship between cold weather and mortality in 2024/25 was seen in those aged 85 years and over. Deaths in this age group increased with colder temperatures, and increased more rapidly below 5° Celsius. Deaths in those aged 75 to 84 years, aged 65 to 74 years and aged 45 to 64 years also followed this pattern, though more gradually.

Impact of influenza circulation on cold-related deaths

The report mainly considers cold-related deaths from all causes occurring during the reporting period and includes a figure showing mortality broken down according to different groups of underlying causes of death recorded on death certificates.

However, previous statistical analyses of cold-weather related mortality have shown that influenza incidence contributes significantly to overall mortality, particularly when influenza circulation coincides with low temperatures. Accordingly, the new analysis presents data for overall cold-related mortality adjusted for changes in influenza activity during the reporting period (see figure). In this respect, the report concludes:

“When influenza activity is adjusted for in the analysis, the relationship between temperature and mortality becomes less steep, especially at colder temperatures. This means that deaths rise less sharply as temperatures fall, once influenza is taken into account. This suggests that a significant proportion of the extra deaths seen during cold periods occur at the same time as increased influenza activity. This does not mean that influenza causes cold-related deaths, but rather that cold weather and influenza tend to overlap and affect the same vulnerable people. The similar timing may be driven in part by cold weather causing increases in influenza transmission […].”

Taken together, these estimates show both (a) the overall impact of cold weather on mortality, and (b) the impact on mortality more directly linked to cold temperatures, alone, that would still be expected to occur even if no influenza was circulating.

Cold-associated deaths by cold episode, England, winter 2024 to 2025

Note. Error bars show 95% confidence intervals.

Further information about the new report and the UKHSA-MetOffice e Weather Health Alerting System is available at:

• ‘How does cold weather affect health?
• ‘What is the difference between Weather-Health Alerts and Severe Weather Warnings?’

Infection reports in this issue

Laboratory confirmed cases of pertussis in England: July to September 2025

Vaccine coverage reports

Shingles vaccine coverage in England: annual report September 2024 to August 2025