Saturday, 24 October, will be mostly sunny and a little warmer, with highs of 17 to 22C, the forecast for Bulgaria shows. The Black Sea coast will also be sunny, with the air warming to 16-18C, about the same as the sea.
Climatologist Prof Georgi Rachev forecast on Friday that October will end warm and that more noticeable cooling will arrive in early November.
The background: Prof Rachev: October to end warm, cold snap expected in early November
Visibility will be poor in lowlands and valleys until noon. A light east-southeast wind will blow over most of Bulgaria. On the coast, visibility will be reduced for a time in places. The wind there will be light to moderate from the northwest, turning southeast in the afternoon.
The mountains will be mostly sunny, with a light to moderate west-southwest wind. It will be about 12C at 1,200 metres and about 7C at 2,000 metres.
On Sunday there will be almost no wind, and any breeze will be light and from the east. Lows will be 5 to 10C. Fog or low cloud will cover many lowland areas until noon, then the sun will take over, with highs mostly of 15 to 20C. Cloud will thicken for a time over southwest Bulgaria, and the mountains may see brief showers in places.
Early next week the wind will turn to the northwest and pick up, and cooler air will move in for a short time. There will be more cloud for a while and some rain in places.
On Tuesday and Wednesday cloud will come and go, with almost no rain. In the west the wind will ease and die down in places. In the east it will blow from the northeast, mostly at moderate strength.
On Thursday most of Bulgaria will still be mostly sunny, and daytime temperatures will be a little higher. In the west the wind will again blow from the northwest and grow moderate, while in the east it will stay northeasterly.
Cloud will build overnight into Friday. The sky will be grey on Friday, with rain in places. The northwest wind will get stronger still, and it will start to turn colder.