Monday will be sunny, with daytime temperatures set to keep climbing, weather forecasters say.

Highs will range from 21°C to 26°C, with Sofia around 23°C. Mornings will be cold, dropping to minus 1°C in some low-lying areas, where frost is expected, while the Black Sea coast will see 14-15°C. Sofia's overnight low will be around 3°C.

Along the coast, it will also be sunny, though some areas will see low cloud or fog in the morning. Highs there will stay at 19-20°C, matching the sea temperature. Waves will be light, at 1-2 points.

In the afternoon, patchy high cloud will move into northern Bulgaria. In the mountains, it will be sunny, with highs of around 18°C at 1,200 metres and around 11°C at 2,000 metres.

Winds will be light to moderate from the north-northeast, picking up to moderate northeasterly along the coast before shifting east in the afternoon. In the mountains, light to moderate winds will blow from the north-northeast.

Tuesday will start with a cool morning and almost no wind. Lows will range from 5°C to 10°C, dipping lower in some low-lying areas, where frost is again possible in parts of western and central Bulgaria. Daytime highs will reach 20-25°C.

Temperatures will rise on Wednesday and Thursday, with light south-southeasterly winds. The days ahead will be mostly sunny, with occasional spells of high cloud.