New figures from Wales’ first annual surveillance report into the impact of cold weather have revealed there were around six more deaths per day on cold days during the winter of 2024-25 compared to milder days.

The report, published by Public Health Wales, found people aged 85 and over were the most affected during colder periods, while women also recorded higher mortality rates on cold days compared to non-cold days after age standardisation.

Researchers stressed the report does not prove cold weather directly caused the deaths, but instead looks at patterns and timings linked to periods of low temperatures.

The winter of 2024-25 was described as slightly milder overall than the long-term average between 1991 and 2020, although there were still 78 days that met the report’s definition of a “cold period” – when mean temperatures were 2°C or below for at least two consecutive days.

Public health experts say the findings are intended to help build a clearer picture of how cold weather impacts health in Wales, particularly among more vulnerable groups.

Dr Behrooz Behbod, Consultant Epidemiologist, said: “This is the first in this series of reports which looks at the public health impact of cold weather, in the context of climate change.

“While the winter of 2024-25 was marginally milder than the climatological baseline built up over 1991-2020, it is important to look at the impact of cold snaps on more vulnerable populations.”

The report also noted several factors were not included in the analysis, including housing conditions, indoor temperatures, fuel poverty and ethnicity data.

Dr Behbod added: “This report is a starting point for further work in this area. It is designed to be a narrative report, and does not show cause and effect or compare groups with each other.”

Public Health Wales said future versions of the report may include wider data to better understand how cold weather affects different communities across the country.