The yellow cold health alert is in effect from 12pm on Monday 17 November 2025 until 8am on Saturday 22 November 2025 across London. The yellow alert has a matrix score of 9. The means:

• a rise in deaths, particularly among those aged 65 and over or with health conditions. We may also see impacts on younger age groups
• a likely increase in demand for health services
• impacts on the workforce affecting delivery of services
• challenges keeping indoor temperatures at the recommended 18C leading to more risk to vulnerable people

Guidance on how to take action on "Winter Readiness" can be found here.