A ferocious early-summer heatwave is tightening its grip on Europe, with forecasters from Rome to Paris warning that the worst is yet to come. Italian meteorologists report that the current hot spell, which began midweek, will intensify and persist into the first days of next week, pushing maximum temperatures to near 40°C across northern and central regions. French authorities have issued similar alerts, with maps showing the mercury climbing to 39°C in the centre of the country by Thursday and potentially reaching 41°C in the shade in some areas. Even the British Isles, more accustomed to temperate summers, are bracing for what Swedish and British meteorologists describe as unusually oppressive heat: parts of the United Kingdom could see 33°C early next week, warmer than Barbados on the same day.

Viewed from Tehran, the picture is dramatically different. Iranian meteorological officials are tracking a separate, unstable weather system that threatens the country’s northwest with violent convective storms. Heavy rain, hail, thunder and strong gusts are forecast for northern West Azerbaijan, East Azerbaijan and Ardabil provinces, where an orange-level warning signals a high risk of flash floods, swollen rivers and damage to temporary structures and agriculture. A broader yellow alert extends across the Alborz mountain range, the Caspian province of Mazandaran, and elevated areas as far east as Semnan and Golestan, with authorities urging residents to avoid stopping near riverbeds and mountain passes.

While Europe’s heatwave is being driven by a stubborn high-pressure system drawing hot air from North Africa, the Iranian instability stems from moist, convective flows over mountainous terrain, typical of late spring but unusually vigorous this year. Forecasters in Tehran note that the thunderstorm activity will be concentrated in the afternoon and evening hours, accompanied by a risk of hail and sudden rockfalls in the highlands. Meanwhile, a gradual warming trend is already underway across Iran’s northern half, with temperatures expected to rise steadily into next week, adding a layer of heat stress to communities that must first navigate the immediate flood threat.

Looking ahead, the European heatwave shows no sign of relenting before the middle of next week. Italian and French models suggest the hottest days will arrive on Monday and Tuesday, with night-time minima staying above 20°C in many urban areas, offering little respite. British authorities have issued multiple heat-health alerts, while Spain’s national weather service has raised warnings to orange in several regions. Across the Atlantic, analysts note that such prolonged early-season heat is consistent with the broader pattern of more frequent and intense heatwaves observed in recent years, raising concerns about strain on power grids, water supplies and vulnerable populations.

In Iran, the immediate focus remains on the convective threat, but the national forecast centre expects a shift to stable conditions by Saturday, followed by a gradual temperature increase across the northern half of the country. The contrast between Europe’s dry, scorching heat and Iran’s thunderous downpours underscores the uneven but equally disruptive nature of this week’s extreme weather, with both regions facing hazards that demand vigilance from authorities and the public alike.