Will I be cold?
Will I be cold in Ljubljana in December?
Verdict
Yes — Yes, cold.
Lows drop to 28°F on average — noticeably cold, especially after sundown.
Day vs. night
Day
37°F
Cold
Direct sun feels cool at best; shade is jacket weather.
Night
28°F
Freezing
Deep freeze after sunset — every exposed step counts.
Why
Ljubljana in December averages highs of 37°F, lows of 28°F, 9 rainy days.
Plan for real winter kit — an insulated coat, warm hat, and gloves rather than a light jacket.