Forecasters predict soaring bank holiday temperatures in London and the south east; see how the heat is affecting people, animals and services
The UK experienced an unusually hot spell as forecasters warned that bank holiday temperatures could climb into the low to mid-30s Celsius. Observations over the weekend included readings above 30C in parts of the south east, and authorities say conditions may push higher across Greater London and neighbouring counties.
Weather agencies emphasise that this surge is notable for the month, driven by a change in wind patterns drawing warm air northwards. Alongside raw numbers, officials have highlighted potential consequences for health, wildlife and infrastructure, prompting localized warnings and practical guidance for vulnerable groups.
Forecast and official criteria
The Met Office and health agencies have set out expectations for continuing warmth into the bank holiday. Forecasters say temperatures could reach around 34C in central and south-eastern areas, with many places feeling considerably hotter than the seasonal norm.
The UK Health Security Agency (UKHSA) and the Met Office issued coordinated heat health alerts covering multiple regions from 09:00 Friday 22 May until 17:00 Wednesday 27 May, flagging risk to those most vulnerable.
How a heatwave is defined
Authorities use a location-specific test: a heatwave is declared when daily maximum temperatures exceed a set threshold for three consecutive days. In practical terms, heatwave thresholds vary by area — for example, the threshold for Greater London is 28C, while some northern parts of the UK have lower thresholds. Meeting these criteria signals a sustained and unusual spell of heat rather than a single hot day.
Where heatwave criteria have been met
The Met Office confirmed that several observing sites have already satisfied the heatwave test. Among the stations reported were Santon Downham, which was the first to meet its threshold at around 11:30, and Heathrow, which reached its criterion at about 11:50 before temperatures climbed further. Other locations on the list include Benson (Oxfordshire), Brooms Barn (Suffolk), High Beech (Essex), Kew Gardens (London), Northolt (London) and Writtle (Essex).
Regional variations and records
Not every part of the UK is affected equally: north-west Scotland and some coastal zones remain cooler and breezier under thicker cloud, while islands such as Jersey already reported record May warmth, with a high of 29.2C recorded in St Helier. Forecasters noted that if temperatures exceed about 32.8C, it would constitute the hottest May temperature on record for the UK.
Impacts on people, animals and services
High temperatures carry practical and health implications. The heat health alerts are aimed particularly at health and social care providers because older adults and people with chronic conditions struggle to regulate body temperature. Advice from charities and health bodies includes staying indoors during the warmest hours, typically between 11:00 and 15:00, taking regular cool baths or showers, and checking on neighbors and relatives.
Zoos and animal collections are also adapting to the conditions. In London, staff have been giving animals specially formulated ice treats — predators have received blood-based frozen lollies, otters have been offered icy shrimp and crayfish portions, and gorillas cooled down on fruit-tea lollies. At Chester Zoo, keepers provided Andean bears with large ice blocks to help maintain hydration and comfort.
Infrastructure felt the strain too. Several villages near Ashford in Kent — including Charing, Challock and Molash — experienced low water pressure and temporary supply interruptions linked to a pumping station fault. The regional water supplier apologised and described operational efforts to restore normal service as quickly as possible.
Practical tips and outlook
Residents and visitors are encouraged to follow straightforward measures to reduce heat risk: drink plenty of fluids, wear light breathable clothing, use shades and blinds to keep interiors cool, limit strenuous activity during peak heat and use fans or cool showers where available. Overnight temperatures may remain uncomfortably high in some urban areas, which can disrupt sleep and compound heat stress.
looking ahead, models suggest the warm spell could persist through the bank holiday before a gradual return to cooler, more changeable conditions as the jet stream shifts. That means many people will need to manage several consecutive hot days — the very criterion officials use when declaring a heatwave — so preparedness and simple precautions remain the priority.
