Astronomical winter officially begins in Bulgaria on Sunday, December 21, at 5:03 p.m. local time, marking the shortest day of the year. In Sofia, daylight will last just 9 hours and 3 minutes, according to Pencho Markishki from the Institute of Astronomy at the Bulgarian Academy of Sciences.

Space weather forecasts indicate that on Monday, December 22, a minor geomagnetic storm of the lowest intensity is expected, after which conditions should stabilize.

The penultimate week of 2025 will start under mostly cloudy skies, with scattered short-term and light rain showers in some areas. Winds will generally be light on Sunday and Monday, though moderate in the eastern regions and in mountainous areas.

Minimum temperatures will range from -2 to 0 degrees Celsius in southwestern Bulgaria, rising to 6-7 degrees in the far east. Daytime highs are expected to hover between 5 and 10 degrees Celsius.

Rain is forecast to intensify on Wednesday, affecting the entire country. Starting Thursday, temperatures are expected to fall. In Northern Bulgaria and on the high plains of the southwest, rain will transition to snow, while precipitation over western regions will gradually taper off. In the mountains, rainfall will continue, with higher elevations seeing a mix of rain and snow.