TL;DR - Last reviewed 23 June 2026
The Met Office has issued a red extreme heat warning for parts of England and Wales, active from 22 June 2026. Heatwaves typically increase household electricity use through fans and portable cooling, push up national grid demand, and can affect energy prices. Practical steps can help households manage costs during prolonged hot weather.
KEY FACTS
- Met Office red extreme heat warning issued 22 June 2026 for parts of England and Wales
- Red is the highest weather warning level, indicating significant risk to life and infrastructure
- UKHSA also issued a Heat-Health Alert for affected regions
- Electricity use rises during heatwaves as households run fans, portable air conditioning and fridges harder
- The Ofgem price cap next updates in October 2026; current unit rates apply through September
What the red heat warning means
The Met Office red extreme heat warning, its highest alert level, indicates that dangerous conditions are expected with a significant risk to life for some people. The warning covers parts of southern England and Wales and is associated with temperatures expected to reach levels that cause serious health impacts, including for those without air conditioning or effective cooling at home.
The UK Health Security Agency issued a corresponding Heat-Health Alert for the affected regions. UKHSA guidance advises keeping rooms cool, staying hydrated and checking on vulnerable neighbours. Schools across parts of the south-west, west country and Home Counties reported closures or early finishes in response to the conditions.
How heatwaves affect household energy usage
Unlike colder countries, the UK has relatively low rates of air conditioning. However, heatwaves still push up domestic electricity consumption through several channels. Electric fans, portable evaporative coolers and portable air conditioning units all draw significant power when run continuously. Fridges and freezers work harder in high ambient temperatures, consuming more electricity to maintain the same internal temperature.
A portable electric fan running continuously uses approximately 35 to 100 watts depending on the model. At current electricity unit rates under the Ofgem price cap, running a mid-range fan for 12 hours per day costs roughly 8p to 26p per day. A portable air conditioning unit uses considerably more power, typically 700 to 2,500 watts, costing approximately 20p to 74p per hour of operation.
What happens to energy prices during heatwaves
For households on the Ofgem price cap, which covers the majority of UK domestic energy customers, heatwave conditions do not directly change the unit rate paid. The price cap sets the maximum rate per unit of gas and electricity and is reviewed quarterly by Ofgem. The current cap applies through September 2026, with the next review taking effect in October 2026.
Wholesale electricity prices on the National Grid can rise during heatwaves as demand increases. However, these wholesale movements affect household bills only at the next price cap review, not in real time. Customers on fixed-rate energy tariffs are protected from any wholesale price movements until their fixed term expires.
Practical steps to manage energy costs during hot weather
Close blinds and curtains on south and west-facing windows during the day to reduce solar heat gain before it enters the building. This is more effective and less energy-intensive than running cooling appliances to compensate.
Open windows and internal doors at night when external temperatures fall below indoor temperatures, using cross-ventilation to cool the building fabric. This reduces the heat load that fans have to manage the following day.
Check your fridge and freezer door seals. Hot ambient conditions accelerate wear on rubber seals, and a poor seal causes the appliance to run continuously to maintain temperature.
Avoid using ovens and hobs during the hottest part of the day. These appliances add significantly to indoor temperatures. Cold meals or microwave use during peak afternoon heat reduces both cooking energy consumption and the indirect cooling load.
If you have a smart meter, the in-home display will show real-time energy consumption. Using this during a heatwave helps identify which appliances are drawing the most power and where reduction is possible.
Warm Home Discount and support schemes
While most government energy support schemes focus on cold weather, households on certain means-tested benefits may be eligible for the Warm Home Discount in the following winter. Applications for the 2026 to 2027 scheme typically open in the autumn. Eligibility is assessed automatically for the majority of qualifying households based on benefit records held by DWP.
Households struggling with energy costs can contact their energy supplier directly to ask about hardship funds, payment plans or a prepayment meter review. Suppliers are required under Ofgem rules to offer reasonable repayment terms to customers in financial difficulty.
Related Guides
Disclaimer: Energy cost estimates in this article are illustrative and based on Ofgem price cap unit rates current as of June 2026. Actual costs vary by appliance, usage pattern and tariff. This article is for informational purposes only and does not constitute energy or financial advice.
What is a red weather warning in the UK?
A Met Office red warning is the highest weather alert level. It means that dangerous conditions are expected and there is a significant risk to life. Red heat warnings are issued when temperatures are expected to reach levels that pose a serious health risk, particularly to older people, children and those with pre-existing health conditions.
Does a heatwave increase my energy bills?
Yes, indirectly. Running fans, portable air conditioning and fridges in high ambient temperatures increases electricity consumption. For households on the Ofgem price cap, the unit rate does not change during a heatwave, but higher usage means a higher bill for the month. A portable fan costs roughly 8p to 26p per day to run continuously; a portable air conditioning unit costs considerably more.
What is the cheapest way to keep cool at home?
Blocking direct sunlight with blinds or curtains during the day and ventilating at night using cross-ventilation are the most cost-effective methods. Both reduce the heat load in the building without using electricity. A standard electric fan is significantly cheaper than any form of mechanical cooling.
Will the heatwave affect the Ofgem energy price cap?
The current Ofgem price cap applies through September 2026 and will not change in response to a single heatwave. The next review takes effect in October 2026. Ofgem sets the cap based on underlying wholesale gas and electricity costs averaged over a period, not on short-term demand spikes.
What help is available if I cannot afford my energy bills?
Contact your energy supplier directly. Suppliers are required by Ofgem rules to offer reasonable repayment plans to customers in financial difficulty. Households on means-tested benefits may also be eligible for the Warm Home Discount scheme, which typically opens for applications in autumn each year.
Sources: Met Office weather warnings (metoffice.gov.uk); UKHSA Heat-Health Alert guidance; Ofgem price cap methodology and current rates (ofgem.gov.uk); National Grid ESO demand data; GOV.UK Warm Home Discount scheme.
