Met Office downplays chance of extreme 39C heat in latest forecast

The Met Office has issued a clarifying statement regarding upcoming temperature projections, moving to temper public expectations of a potential 39C heatwave. While some long-range forecasting models have suggested extreme highs approaching that threshold, official forecasters indicate that the conditions are unlikely to Mirror the record-shattering intensity observed late last month.

The divergence in outlook follows a period of intense heat that saw record-breaking temperatures across the UK. On Friday, June 26, the country experienced its hottest June day in history, with a provisional peak of 37.7C recorded in Lingwood, Norfolk. This surpassed a reading of 37.3C at Santon Downham, Suffolk, on the same day. Records were also set elsewhere: Wales recorded 35.9C at Cardiff Bute Park, and Northern Ireland matched its previous record of 30.8C. These events were characterized by high humidity, which reduced the body’s ability to cool through sweating, and oppressive overnight temperatures, including a new record high daily minimum of 23.5C. The Met Office noted that four nights last week saw temperatures remain above 22C, hindering the ability of buildings to cool down.

Media additions

Despite reports circulating that indicate a 39C peak for next week, Tony Wisson, the Met Office deputy chief forecaster, has downplayed the probability of such an outcome.

"Although a return to heatwave conditions is looking increasingly likely for some areas, the likelihood of such extreme high temperatures or high levels of humidity as last week is currently low."

Tony Wisson, Met Office deputy chief forecaster, via Mirror

The Met Office emphasizes that the anticipated spell of warm weather is expected to be less extreme than the June event, though it notes that the heat may persist for a longer duration. Current signals suggest that while high pressure building from the Azores will bring settled, warm conditions across England and Wales through the upcoming week, peak temperatures are forecasted to be more moderate than previous projections. Mr. Wisson indicated that temperatures could approach the high 20C range across parts of England, potentially reaching 30C in parts of the southeast, with values of mid to high 20C in Wales.

This assessment comes as the UK Health Security Agency (UKHSA) implements a yellow heat-health alert covering the East Midlands, South East, South West, East of England, and London. The alert is active from 12pm on Saturday, July 4, until 5pm on Wednesday, July 8. The agency warns that these conditions could result in increased usage of healthcare services by vulnerable groups, rising indoor temperatures, and a greater number of water-related incidents, including risks from cold-water shock and drowning.

Current Outlook and Health Guidance

• Alert Period: 12pm, July 4 – 5pm, July 8.
• Primary Concerns: Increased health service demand, heat stress for vulnerable populations, rising indoor temperatures, and water-related safety risks.
• Expected Conditions: A shift toward more settled, warm, or very warm weather; less humidity compared to June; lower peak temperatures.
• Regional Variability: Far northern areas of the UK may experience occasional rain and stronger winds, while the south remains more consistently hot.

The Met Office reports that while confidence remains low regarding the exact progression of the weather for the remainder of July, high pressure is generally more likely than low pressure. This pattern typically suggests a trend of above-average temperatures. However, this heat may be periodically interrupted by showers or thunderstorms, which are more probable in the south or, occasionally, the north and west. Looking further ahead, the Met Office notes that the UK may see a greater than normal chance of hot conditions developing at times through the start of August, though unsettled interruptions could become more common.