(Bloomberg) -- Parts of Europe are baking in an unusually warm October, raising further concerns of the impact of rising greenhouse gas emissions on the climate while delaying the start of the continent’s heating season.

Portugal has issued yellow alerts for high temperatures over the next few days. In Spain, highs in Madrid will clock in above 30C (86F) on both Saturday and Sunday, at least 6C above normal, according to a forecast by Maxar Technologies.

London, which endured some cold and bleak weather during the summer, is forecast to reach at least 22C on three of the next five days, while Paris climbs to 26C on Tuesday. Temperatures are also expected to be above average in Germany and Italy.

“Climate change is already significantly affecting the UK’s weather, with more and more events becoming ever more extreme,” said Grahame Madge, a spokesman for the UK’s Met Office. He said Great Britain is expected to see temperatures about 6C above average for early October.

Read more: September Broke the Global Heat Record by an Absurd Margin

Portugal’s Institute for Sea and Atmosphere said on Wednesday that the current weather pattern may extend into next week.

Spain experienced six consecutive days of extraordinarily high temperatures from Sept. 28 to Oct. 4, and summer-like readings could persist for an unprecedented 16 days, according to Aemet, the country’s meteorological agency.

“It’s definitely quite unseasonably warm and it’s probably pretty close to record warmth,” said Steven Silver, senior meteorologist at Maxar’s Weather Desk.

Read more: Europe Set for Mild October, Delaying Start of Heating Season

On the island of Madeira in the Atlantic, south of Portugal, a record high for October was recorded on Thursday in the city of Funchal. The temperature reached 34.7C, exceeding the prior high of 34.3C set in October 2014.

Beaches in the greater Lisbon area were packed on Thursday, a national holiday, and may fill up again over the weekend as locals and tourists seek some autumn swim-time.

The Portuguese Federation of Lifeguards issued a statement last week warning about the risk of drowning since many beaches are no longer monitored by lifeguards after the main summer season ends, the news agency Lusa reported.

Earlier this week, scientists confirmed that the September global average temperature broke records by an “extraordinary” margin. The temperature anomaly for the month was roughly 1.7C above pre-industrial levels, above the symbolic 1.5C mark set as the stretch goal in the Paris Agreement.

Carbon dioxide emissions from burning fossil fuels regarded as are the main driver of rising temperatures. The global average temperature this year has also seen a boost from El Niño, a natural climate shift in the Pacific. Other factors, such as a decline in cooling aerosol pollution from ships, may also be pushing temperatures up incrementally.

--With assistance from Laura Millan and Ellie Harmsworth.

©2023 Bloomberg L.P.