Bonfire night events in Cork city have been cancelled as heavy rain is sweeping across the county.

A Status Yellow rainfall warning is in place for Cork and Waterford until 6pm with up to 40mm of rain likely in places.

Met Éireann has also issued a Status Yellow rainfall warning for Leinster, which will be in place from 6pm this evening until 6am tomorrow.

It said scattered thundery downpours will push northwards with between 25mm and 40mm of rain possible in places.

Tonight's Bonna Night events at seven Cork city parks have been cancelled due to the poor weather conditions.

Stephen Scully of the council's Parks Department said it is the first time in 12 years that the organised event has had to be cancelled, but the decision was taken on health and safety grounds earlier this morning.

Bonna Night takes place on St John's Eve - 23 June - every year and in the past unregulated bonfires caused damage to green areas and led to incidences of anti-social behaviour.

Mr Scully said that for the past 12 years, family-friendly events have transformed the tradition and crowds of up to 15,000 people could be expected at events across the city's parks.

He said it is very disappointing that tonight's festivities have had to be cancelled.

Bonna Night is an old pagan tradition, which honoured the goddess Aine and was later transformed into a christian celebration marking the birth of St John the Baptist.

La Cocina Pública, part of the Cork Midsummer Festival, has also been cancelled.

A warm front moving across Europe from the Sahara will see temperatures here hit the mid-to high 20s by mid week, although heavy thundery downpours are forecast in places as well.

Much of western Europe is likely to see temperatures as high as 40C in an "unprecedented" June heatwave.

A wave of hot air coming from the Maghreb in North Africa and Spain will push up temperatures starting this weekend and hitting a peak around mid-week. 

Spain's meteorological agency (Aemet) has issued a "yellow alert" for severely bad weather for today and said it expects the country to see a "hotter than usual" summer, like last year.

In Germany, forecasters are predicting temperatures up to 37C on Tuesday and 38C on Wednesday, with similar hot weather also expected in Belgium and Switzerland.

The British Met Office said it was particularly concerned that the heatwave could trigger "violent storms" and warned people to expect "hot, humid and unstable" weather.

Greece will be one of the countries most affected by the heatwave with temperatures hitting 39C.

In France, meteorologist Francois Gourand said the heatwave is "unprecedented for the month of June" and will no doubt beat previous heat records. 

Starting on Tuesday, France will see temperatures from 35 to 40C, which will remain high at night offering little respite from the heat, forecasters predicted.

"Since 1947, only the heatwave of 18 to 28 June, 2005, was as intense," said Meteo France, adding the scorching weather would probably last a minimum of six days.

Additional Reporting AFP