The Environment Agency has warned of storms which are to hit the west this evening, from where they will spread inland.

Smaller streams and rivers could rapidly rise and a strong northerly wind of up to 100 km/h will sweep through the coast, south-west.

"We expect a strong northerly wind at the coast somewhere around 8 p.m. At this time, fierce storms will hit western Slovenia and travel inland," meteorologist Benedikt Strajnar told the STA on Sunday.

Localised fierce storms are possible in many places, involving hail, gusts of wind, heavy rain, and some smaller streams and rivers may also swell, he said.

According to Strajnar, the west is especially at risk from late afternoon to early night, with the worst weather expected around 8 p.m.

Daytime highs will nevertheless range between 26 and 33 degrees Celsius, up to 37 in the west.

Localised showers and storms will first spread from the north to the rest of the country.

However, the rain will stop by Monday morning, and it will be mostly sunny during the day.

Before this year's fourth heath wave lets go, some towns recorded extremely high temperatures last night.

In the Vipava Valley in the south-west, they barely dropped below 30 degrees Celsius, with the town of Podnanos holding the record of 29 degrees Celsius.

"These high temperatures in the Vipava Valley are related to the bora wind which was blowing most of the night," the meteorologist explained.

However, he could not yet say whether any new temperature records were set last night, but added that "we were definitely very close to them".