When is the next heatwave in London? Forecast predicts major mid-June temperature spike

For millions in London battling the grim weather and Tube strikes this week, the record-breaking May heatwave may seem a distant memory.

Thunderstorms, gusts and cool temperatures have faced those queuing for buses or cycling home to beat the RMT walkouts.

It's a jarring change from the almost unbelievable 35.1C experienced in London on May 26 - just over a week ago - during a five-day heatwave that sparked a major health alert.

But for those of you missing the sweltering weather, the latest forecasts for London suggest we won't have to wait long to see another sharp spike in temperatures.

BBC Weather is predicting conditions will get steadily warmer next week, with the mercury rising from a high of 19C on Monday, June 8 to 24C on Friday, June 12.

It's set to get hotter still over the following few days, with predicted highs of 27C on Sunday, June 14, 26C on Monday, June 15 and 28C on Tuesday, Jun 16.

Just a small uptick in the temperature forecasts would raise the prospect of a heatwave, which in London is defined as three consecutive days with highs of at least 28C.

It comes as the Met Office's three-month summer outlook predicts higher-than-normal chances of hotter weather during June.

It also suggests “an increased chance of heatwaves and heat-related impacts” throughout the summer.

Scientists from the World Meteorological Organisation (WMO) reckon a warming “El Nino” global weather event is now 80% likely to happen this summer.

Lightning flashes were seen above homes in Bromley on Tuesday evening (Getty)

The UN body has warned countries to prepare for the natural phenomenon, which sees the warming of sea surface temperature in the tropical Pacific Ocean push up global temperatures, compounding human-driven climate change and triggering even more extreme weather.

An El Nino event this year is likely to take place between June and August 2026, according to the WMO forecast models.

Probabilities that it will continue until at least November is near or above 90%, the scientists also found.

The UN said countries should treat the potential event as “an urgent climate warning” as the world already faces devastating impacts from increasingly severe weather, as fossil fuel pollution continues to drive global warming.

While some uncertainty remains about the El Nino event’s peak strength and timing, the forecast models suggest it will be at least moderate and possibly strong.

It comes after the last El Nino event contributed to soaring temperatures that saw 2024 become the warmest year on record.