A UK heatwave is defined as a period of at least three consecutive days when daily maximum temperatures meet or exceed the heatwave temperature threshold for a particular location.
Those thresholds vary by county, reflecting the fact that what is unusually hot in one part of the UK may be different elsewhere.
This means a heatwave is not simply based on one hot day, or even on the UK’s highest temperature. It depends on both location and duration. A hot spell may bring temperatures well above average, but it only becomes a heatwave where the relevant local threshold is met for three days or more.
Are we still technically in heatwave conditions?
The answer depends on where you are. Much of England and parts of Wales are continuing to see maximum temperatures above normal, with southeast England expected to reach around 30°C on Saturday.
However, the heat is not uniform across the UK. By Sunday, temperatures are expected to fall back to the low-to-mid 20s in the south and mid-to-high teens further north, bringing a brief reprieve from the recent heat.
Under the Met Office definition, if temperatures dip below the relevant local heatwave thresholds, then the current heatwave spell would come to an end for those areas. If temperatures then rise again and meet the criteria for three consecutive days, that would be treated as a new heatwave rather than a continuation of the previous one.
This weekend brings change for some, but not for others 🌧️☀️
— Met Office (@metoffice) July 24, 2026
Here are some details for the weather to come 👇 pic.twitter.com/wLJTiegmy0
Localised rather than widespread
Heatwave conditions can be described as localised when a small region or a small number of locations meet or exceed their thresholds. A widespread heatwave occurs when thresholds are met across a larger region, such as multiple counties.
That distinction is important in the current forecast. Some locations, particularly in the south and southeast, may continue to see very warm or locally hot conditions for a time, but other parts of the UK are already seeing, or are forecast to see, cooler and more changeable weather.
A cooler interlude on Sunday
Sunday looks to bring a noticeable change. Rain and showers are expected across many areas, whilst temperatures will be closer to or just below average. Relative to Friday and Saturday the biggest change in temperature on Sunday will be over Wales and northern, central and eastern England. Sunday night will then be a little cooler than recent nights, with a number of places dropping into single figures.
For many, this will feel like a shift after the recent hot weather. It also matters from a heatwave-definition point of view, because the three-day threshold has to be maintained locally for heatwave conditions to continue.
READ MORE: Will the heat return?
Could there be another heatwave next week?
There are signs that temperatures will rise again early next week. A return to at least the mid-to-high 20s looks probable, with conditions becoming very warm or hot in the south and southeast by midweek.
If temperatures rise high enough to meet local thresholds for three consecutive days, then another heatwave could be recorded. So far, 2026 has seen three defined heatwaves in May, June and July; if temperatures dip below heatwave criteria before rising again, a further qualifying spell would be counted separately, potentially as a fourth heatwave.
However, isolated high temperatures alone would not necessarily be enough. If only one or two stations reach heatwave criteria, that would not be defined as a heatwave.
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