Thirty-five point one degrees Celsius. At Kew Gardens in London. In May.

The UK broke its all-time May temperature record on Monday, then did it again the very next day. Monday delivered 34.8°C in the capital, itself a new benchmark. By Tuesday, thermometers at Kew Gardens climbed to 35.1°C — a reading that would be unremarkable in high summer but is, in the final week of May, without precedent. The previous May record of 32.8°C had stood for over a century, first set in 1922 and matched only once, in 1944.

Across the continent, temperatures have been running 10 to 15°C above the seasonal average, according to the Guardian’s weather tracker. This is not a gentle nudge above normal. It is the kind of anomaly that replaces one month’s climate with another’s — May wearing August’s clothes.

The Heat Dome

The mechanism is a persistent area of high pressure — a “heat dome” — that has locked itself over Europe, trapping warm air beneath it and deflecting the weather systems that might otherwise bring rain or cloud cover. Heat domes are a known meteorological feature. What makes this one unusual is its intensity, its geographic reach, and its timing: this is May, not July.

France recorded its hottest May days on record, with temperatures hitting 36°C on both Monday and Tuesday. A French government spokesperson confirmed that the heat had been responsible for seven deaths this week, either directly or indirectly — a toll that underscores the particular danger of early-season heat, when bodies have not yet acclimatised to summer conditions.

Ireland also rewrote its record books. Thermometers reached 28.8°C at weather stations in Killarney, in the south-west, and Clonmel in the south. For a country where 20°C in May counts as a genuinely warm day, the margin was stark — and the speed with which records fell, notable.

Nights That Offer No Relief

The extremes are not confined to daylight hours. Overnight on Tuesday, Camborne in south-west England dropped to just 21.4°C — what meteorologists classify as a “tropical night,” where temperatures never fall below 20°C. The body relies on cooler night-time hours to recover from heat stress. When that window closes, the physiological burden accumulates.

Tropical nights are rare enough in southern England during midsummer. In May, they are virtually unheard of. That one occurred alongside shattered daytime records suggests a heat event operating on multiple fronts simultaneously: hot days, warm nights, and no meaningful pause in between for bodies to recover.

The View Forward

Forecasts indicate temperatures will remain 5 to 10°C above average through the rest of this week before gradually moderating for the UK into next week, according to the Guardian’s weather tracker. The heat dome will loosen. The immediate crisis will ease.

The broader pattern will not. What makes this week significant is not any single record but the sheer concentration of them — set in multiple countries, across day and night, in a month that does not historically produce this kind of heat. Climate scientists have long projected that a warming continent would experience extreme heat arriving earlier in the year, lasting longer, and pushing further north into regions previously considered temperate. The data emerging this week fits that trajectory with uncomfortable precision.

Seven deaths in France. Records broken on consecutive days across three countries. Tropical nights before the calendar reads summer. The numbers require no embellishment.

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