23rd June: RED heat health alert updated for London

The red heat health alert is in effect from 1AM on 24/06/2026 until 11PM on 25/06/2026 across London. The red alert has a matrix score of 16. This means:

Severe impacts are expected across health and social care services due to the high temperatures, including:

• increased risk to life across the whole population, with significant impacts on older people
• significantly increased demand on all health and social care services
• the heat affecting the ability of the workforce to deliver services
• hot indoor environments making provision of care challenging and national critical infrastructure failures, such as generators and power outages
• water-related incidents may increase, including risks from cold-water shock and drowning

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

How to take action if you have a duty to respond

Please review the Weather Health Alert System user guidance to explain how you can use the information contained within the alerts to respond to the forecast weather.

We provide guidance on how to take action for a range of professional groups with a duty to respond, with action cards available for commissioners, health and social care providers, voluntary and community sector, and national government. Summary action cards are also available below:

• commissioners
• voluntary and community sector
• care homes and other residential settings
• services delivering care to people in their homes
• hospitals and other healthcare settings

For an overview of the weather alerts in place across England, please check the UKHSA data dashboard.

The Met Office may issue National Severe Weather Warnings (for example, extreme heat) with short notice, so you can take appropriate action. Check the Met Office Website to see the National Severe Weather Warnings currently in place.

You can also find information of the latest weather forecast on the Met Office website.

How to protect yourself if you are vulnerable

While exposure to hot weather can affect anyone, some people are particularly at risk. We have published guidance on staying safe during hot weather.

Planning for adverse weather

All organisations should read the Adverse Weather and Health Plan. This is important if you provide health and social care. The plan explains what you should do before and while a heat health alert is in place.

To support local planning, please check the guidance on local resilience forums.

About heat health alerts

Chief executives of the following organisations in England receive heat health alerts:

• health trust providers of NHS commissioned care
• local authorities
• social care organisations

The Heat-Health Alert Service in England runs from 1 June to 30 September each year, in partnership with the Met Office. This is the period when high temperatures are likely to occur.

If we observe high temperatures outside of this period, we will issue an extraordinary heat health alert. If this happens, stakeholders should take the usual public health actions.

You can share this email with your organisation or sign up to receive alerts using our registration form. We have a separate form if you would like to update your registration details.

Please let us know if you have a question or have a problem with your subscription. You can also unsubscribe from this service.

UKHSA and the Met Office use the Risk Matrix to assign a risk score for each alert. Users can refer the alert’s risk score to the matrix to understand the severity of the alert and likelihood of its impact.

Updates to heat health alerts

UKHSA and the Met Office make daily risk assessments.

Overview of hot weather over the next 5 days

An exceptional spell of very hot and humid weather is now expected for much of England until at least Friday. Early thunderstorms clearing the southeast, otherwise, widely fine, dry and sunny on Tuesday. Becoming hot or very hot in central and southern parts of England, reaching the mid to high 30s Celsius. Staying dry and sunny on Wednesday and Thursday, with exceptional heat and humidity building across much of England, especially in central and southern areas. Very warm, even tropical nights, making for some very uncomfortable nights for many through the remainder of the week, especially in larger cities, with high humidity. Temperatures still potentially high up to the weekend, with the highest probabilities in the East Midlands, east and southeast of England on Friday and possibly Saturday. However, there is some uncertainty with extent and timing of any thundery breakdown moving in from the west. Regarding exacerbating factors, winds will be mostly light, offering little relief. Pollen levels will be widely high or very high. Air pollution levels will deteriorate, with widespread Moderate levels spreading to affect much of southern and central Britain, likely lasting through midweek.

Overview of hot weather over the next 6 to 15 days

Sunday, a band of rain moves east across the UK. This likely heralds a change to temperatures closer to normal though still warm in the southeast. For the rest of this period, confidence is low with temperatures likely above average with the chance of hot spells.

Overview of hot weather over the next 16 to 30 days

Low confidence in any detail, however, probabilities of warmer than average conditions and likelihood of hot spells appears to be greater relative to climatology for the end of June and into early July. Toward mid-July, weather possibly turning more unsettled with some moderation of temperatures likely.