Celje, where it's located

The climate of Celje is continental, with cold winters and warm summers.
The city is located in the central-eastern part of Slovenia, at an altitude of 340 meters (1,100 feet).
The average temperature of the coldest month (January) is of -0.3 °C (32 °F), that of the warmest month (July) is of 20.4 °C (69 °F). Here are the average temperatures.
Celje - Average temperatures
Min (°C)-5-40491214131061-3
Max (°C)471216222527262216104
Min (°F)232532394854575550433427
Max (°F)394554617277817972615039

Precipitation amounts to 1,115 millimeters (43.9 inches) per year: so, it is quite abundant. It ranges from 45 mm (1.8 in) in the driest month (January) to 130 mm (5.1 in) in the wettest (June). Here is the average precipitation.
Celje - Average precipitation

On average, there are around 1,730 sunshine hours per year. Here are the average sunshine hours per day.
Celje - Sunshine


Best Time

The best times to visit Celje are spring and autumn, and in particular, the months of May, June and September: daytime temperatures are pleasant, although it's better to bring a sweater and a jacket for the evening. In July and August, the temperature is usually not too hot, however, there is the risk of some very hot days, which can happen, though more rarely, also in the second half of June and in the first half of September.