The yellow heat health alert is in effect from 6pm on Wednesday 13 August 2025 until 6pm on Monday 18 August 2025 across London. The yellow alert has a matrix score of 9. This means:

There is potential for significant impacts across health and social care services from high temperatures, including: 

• a rise in deaths, particularly among those aged 65 and over or with health conditions. There may also be impacts on younger age groups
• a likely increase in demand for health services
• internal temperatures in care settings (hospitals and care homes) may exceed the recommended threshold for clinical risk assessment
• the heat affecting the ability of the workforce to deliver services
• indoor environments overheating increasing the risk to vulnerable people living independently in community and care settings

You can see all the weather health alerts currently in place across England on the UKHSA data dashboard.