The weather on September 5 is expected to be mostly sunny across the country. In the mountainous regions, cumulus clouds will form, leading to rain showers and thunderstorms in the afternoon. A light easterly-northeasterly wind will prevail, with a light to moderate northerly-northwesterly wind in Northeast Bulgaria. Daytime temperatures will range between 29°C and 34°C, with Sofia seeing highs around 30°C.

Along the Black Sea coast, the day will also be mostly sunny. Winds will be light to moderate from the north-northwest, shifting to easterly-southeasterly in the afternoon. Temperatures will reach between 27°C and 29°C, with sea water temperatures between 26°C and 27°C. The sea will have a wave height of 1 to 2 degrees on the Douglas scale.

In the mountains, the weather will be mostly sunny, but rain showers and thunderstorms are likely around midday and in the afternoon. Winds will be light to moderate from the north-northwest. Temperatures will reach around 23°C at 1,200 meters and approximately 16°C at 2,000 meters.