Are 'heat spikes' becoming more common?

Here is the latest breaking news from around the world: Are 'heat spikes' becoming more common? Image source, GettyImage caption, Much of the UK experienced soaring temperatures in an early season May heatwave across England and WalesBySimon King Lead Weather PresenterPublished19 minutes agoWith temperatures hitting a record breaking 35. 1C this week, it has been an exceptional May heatwave.

In its build up we saw temperatures increase rapidly - by up to 10C in just two days in some locations. Historically, it would have been more common to see a gradual increase of a degree or two each day. The rapid onset from an average to high, even extreme, temperature - or a "heat spike" - is something I and fellow meteorologists have noticed happening more often.

The Details

Ed Hawkins, professor of climate science at the University of Reading, told the that "Today's heat events are emerging earlier, intensifying faster and occurring across a much warmer background climate". While according to Dr Ségolène Berthou from the Met Office, "We can't explicitly say that extreme heat temperatures spike faster now than they did in the past," experts are beginning to piece together a number of other factors that could provide an explanation. Hotter days give a 'head start'The Met Office's State of the Climate 2024 report shows that in parts of the UK the hottest days are warming around twice as fast as typical days.

Compared with 1961–1990, the number of days 5C above average has doubled, while days 10C above average have quadrupled. Or as Dr Berthou expresses it: "Extreme temperatures are increasing faster than average temperatures. "Summer daytime highs are already about 1.

5C warmer when comparing the 1991-2020 climate period with 1961-1990. 3 C in July 2022, Met Office studies showed the likelihood of exceeding 40C is now more than 20 times higher than in the 1960s. The higher baseline - or head start - means similar summer weather patterns now reach heatwave and extreme heat thresholds more easily.

What Experts Say

Drier ground, drier air – a loaded dice for faster warmingImage source, EPAImage caption, Drier ground heats up faster and we are likely to see more frequent droughts drying up reservoirs, such as this in Derbyshire in August 2025How quickly temperatures rise isn't just about how warm the air starts out, but how dry the land and atmosphere are. Dry ground heats up faster than moist ground because less energy is used for evaporation and more goes directly into raising temperature. There is strong evidence that UK summer soils are becoming drier as the climate warms, with Met Office projections showing earlier seasonal drying and more frequent droughts, particularly in southern and eastern England.

The same principle applies higher above the ground. Large, slow‑moving areas of high pressure - often called blocking highs or heatdomes - are large areas of sinking air. Like squeezing a sponge, the descending motion dries the air out and when you add in the fact the air is compressed, this also adds to the air heating up.

The story has become one of the most prominent items on the global agenda.