Guidance

Cold-Health Alerting system: overview

The Cold-Health Alerting system provides suggested actions to protect health and reduce cold-related harms.

Applies to England

About the Cold-Health Alerting system

Cold-Health Alerts (CHA) are issued when cold weather is forecast that could lead to significant impacts on health. During the winter, the UK Health Security Agency (UKHSA) and the Met Office monitor weather forecasts and where an advserse cold weather event is predicted a joint risk assessment is carried out and the appropriate level of alert is issued. 

The core CHA period within which the alerts are issued is 1 November to 31 March each year, although extraordinary alerts may be issued if an episode of cold that can impact health occurs outside of this period.

The alerts are given a colour (yellow, amber or red) based on the combination of the impact the weather conditions could have, and the likelihood of those impacts occurring.

Cold-Health Alerting system: impact and likelihood risk matrix

This figure shows the yellow, amber and red risk matric used to communicate the likelihood of a cold weather event happening and the level of impact it will have.

During the core CHA period, cold-health planners are issued every Monday and Friday, to provide regional forecasts of weather conditions for the following 5 days, 6 to 15 days, and 16 to 30 days.

The alerts are aimed at professionals within the health and social care sector and those who have a role in responding to cold weather to protect health. They are freely available and can be accessed by the public. Those wishing to be notified when an alert is issued should complete the registration form to receive them by email. The Cold-Health Alerting system is part of the Weather-Health Alerting (WHA) system and further information is available in the Weather-Health Alerts System user guide.

Updates to this page

Published 24 September 2025

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