The United Kingdom is bracing for a summer that is twice as likely to be hotter than usual, according to the Met Office’s latest three-month outlook. This forecast, covering the meteorological summer from June 1 to August 31, 2025, also warns of an increased risk of heatwaves, a development that follows the country’s sunniest and driest spring on record.
Between March 1 and May 27, 2025, the UK basked in approximately 630 hours of sunshine, marking the brightest spring in over a century. Alongside this, the nation experienced its driest spring in more than 100 years, setting the stage for what meteorologists predict will be a notably warm summer. On May 31, the final day of spring, temperatures soared to 8°C above the seasonal average, with Heathrow Airport in west London recording a high of 26.7°C. This spike in temperature hinted at the potential for a scorching summer ahead.
According to the Met Office, the probability of a hotter-than-average summer is more than double the usual likelihood, with a 2.3 times greater chance of elevated temperatures across the UK. Average temperatures during these months typically range from 10°C to 17°C nationally, with the south-east of England often experiencing the warmest conditions, averaging between 16°C and 17°C.
However, the Met Office is careful to clarify that a hotter summer does not guarantee continuous heatwaves or prolonged periods of extreme heat. A spokesperson explained, "The increased chance of hotter than average temperatures is not a guarantee of prolonged hot weather or heatwaves, but it does mean that heatwave conditions could be reached at times." They further cautioned that the forecast might reflect a mix of hot and cool days, warm nights, or less intense warmth rather than sustained heatwave conditions.
Heatwaves in the UK are officially declared when daily maximum temperatures meet or exceed specific thresholds for at least three consecutive days. These thresholds vary by region, generally ranging between 25°C and 28°C. For instance, Wales and Scotland must reach temperatures above 25°C, while London and parts of the East Midlands have higher thresholds set at 28°C due to their typically warmer climates.
The current outlook aligns with recent trends, as the UK has seen a series of warm summers over the last decade. The last time the country experienced a summer that could be classified as "cool" was in 2015. Summers in 2018 and from 2021 to 2023 were also predicted to be hot, underscoring a pattern consistent with the broader impacts of climate change.
Scientists attribute much of this warming trend to human-induced climate change. The Met Office’s State of the UK Climate report highlights that summers have become warmer, wetter, and sunnier in recent decades. Extreme temperature events have become more frequent, with the number of "hot" days (28°C or above) more than doubling and "very hot" days (30°C or above) more than tripling between 2014 and 2023 compared to the 1961-1990 baseline.
One significant factor potentially amplifying this summer’s heat is an ongoing marine heatwave in the seas surrounding the UK. Sea surface temperatures in north-west European waters are currently 1.5°C to 2.5°C warmer than average. This extra warmth in coastal waters could elevate air temperatures and moisture levels, possibly resulting in more intense summer storms.
Despite the heat predictions, rainfall forecasts remain less definitive. Most seasonal outlooks suggest near-average rainfall for the UK overall, with some hints from the Met Office that early June could be wetter than usual. Other agencies, such as the European Centre for Medium-Range Weather Forecasts (ECMWF) and DTN, lean towards a slightly drier season. Nonetheless, summer rain tends to be highly variable, with some regions experiencing heavy showers and others remaining dry. For example, in 2021, parts of southern England received nearly double their usual summer rainfall, while western Scotland saw only half.
Water scarcity is a pressing concern, especially following the dry spring. Reservoir levels and river flows dropped significantly across the country, prompting the Environment Agency to declare drought status for the north-west of England. This region faced its driest start to spring in 69 years, with many reservoirs at historic lows for this time of year. Water companies are hoping for a wetter summer to replenish supplies and avoid restrictions on water use.
Wind forecasts for the summer period indicate no strong signals for above or below-average wind speeds. This suggests that the UK is unlikely to experience frequent deep low-pressure systems that bring stormy weather. However, the forecast includes an active Atlantic hurricane season, which could indirectly affect the UK later in the summer if decaying tropical storms approach the British Isles.
As temperatures rise, health officials emphasize the importance of staying cool and hydrated. The NHS recommends avoiding the sun during peak hours between 11 a.m. and 3 p.m., wearing hats and light clothing, applying sunscreen, and steering clear of strenuous activity during the hottest parts of the day. Cooling measures such as cold showers and drinking plenty of fluids are advised, while keeping living spaces cool by closing windows during the day and opening them at night can help mitigate heat stress. Electric fans may be beneficial when temperatures remain below 35°C.
While the Met Office’s long-range forecast does not predict specific weather events on any given day, it serves as a crucial tool for government agencies, businesses, and local authorities to prepare for the season ahead. It highlights the increasing role of climate change in shaping the UK's weather patterns and underscores the need for resilience against extreme heat and its associated impacts.
In summary, the UK faces a summer that is statistically more likely to be warmer than usual, with an elevated risk of heatwaves and the challenges they bring. This prediction is rooted in a combination of record-breaking spring conditions, ongoing marine heatwaves, and the broader context of a warming climate. While variability remains, and cooler spells are still possible, the trend points toward a summer that demands preparedness and caution.
