Europe faces second 'intense heat wave' of the summer after hottest June on record

Record-breaking temperatures are expected in Paris and London this week.

LONDON -- Millions of Europeans are facing a second heat wave of the year as record breaking temperatures sweep across the continent this week.

Meanwhile, millions of Londoners are bracing themselves for the hottest day in British history, with the Met Office warning there is a 60% chance temperatures could reach 102.2 F on Thursday.

Similar temperatures are expected in Paris, with Meteo France predicting that temperatures could reach between 104 F and 107.6 F on Thursday.

Huge areas of Switzerland, Belgium, the Netherlands and Germany are all under a heat alert, according to the World Meteorological Organization (WMO). The heat wave could accentuate the risk of drought and an “extreme fire risk” in Portugal and Spain.

The July heat wave comes after the world experienced the hottest June on record.

Climate experts have said that such heat waves early in the summer are likely to become more frequent as the planet heats up.

“The July heat wave follows an unusually early and exceptionally intense heatwave in June, which set new temperature records in Europe and ensured that the month of June was the hottest on record for the continent, with the average temperature of 2° Celsius above normal,” Clare Nullis, spokesperson for the WMO, told ABC News. “Such heat waves are consistent with climate scenarios which predict more frequent, drawn out and intense heat events as greenhouse gas concentrations lead to a rise in global temperatures.”

Fires are raging across central Portugal and the Arctic, she said, and the “high temperatures pose a major threat to people’s health.”

“As to whether it compares to 2003, the answer is yes and no,” she said. “Temperatures are certainly comparable in some countries, and we expect many temperature records to be broken in France, Germany, Belgium, the Netherlands and possibly [the] U.K. But since the 2003 heat wave, there has been huge progress in heat early warnings and heat-health action plans to protect people's health.”