Meteorologist Brane Gregorčič from the Environment Agency says that Slovenia is unlikely to get noteworthy rainfall before the year is out, let alone snow.
There is a high-pressure area over the Mediterranean that is expected to persist for some time.
This is the main cause of the higher-than-usual temperatures and dense fog in low-lying areas, even on the seaside.
Conversely, at altitudes of over 1,500 metres it is sunny and temperatures will mostly remain above 5 degrees Celsius, Gregorčič said.
Absent serious rainfall by the end of the month, December 2015 will set the record for the driest December since measurements began.
Temperature records are also expected in the mountains, according to Gregorič.
The late-December weather is not surprising given how warm the year has been.
In central Slovenia, for example, all months but February and October had above-average temperatures.
While daytime peaks were below record, night temperatures were exceptional, in particular in early July.
Ljubljana, for example, recorded a morning low of 23.3 degrees on 8 July, a new record.
Elsewhere nigh time temperatures at the time were even a degree higher.