Bulgaria's national weather service has called code orange for dangerous weather for Wednesday in the Blagoevgrad, Ruse and Vidin regions due to the European heatwave that has gripped the country.

All other Bulgarian regions have been placed under code yellow for potentially dangerous weather over temperatures set to reach 35 degrees Celsius and above.

Tuesday temperature records were set on two locations - the cities of Ruse (39.6 C) and Montana (38 C).

For many locations in the north and south-west, highs Wednesday can reach 39 C and above, warned the National Insitute of Meteorology and Hydrology at the Bulgarian Academy of Sciences.

As usual, temperatures along the Black Sea coast are expected to be lower, max. 31-34 C, with sea water at 25-26.

Weather in Bulgaria's mountains is expected to be warm, dry and stable, with excellent conditions for hiking.

Temperatures are set to be increasing with a couple of degrees every day until Sunday, warned the Meteorology Institute.