Last updated: August 22, 2025
In December, the average temperature in Trn, Bosnia and Herzegovina hovers around 4°C (39°F). Expect a chilly minimum of -9°C (16°F), while the mercury can rise to a comfortable maximum of 18°C (65°F). Be prepared for a relatively wet month, with 105 mm (4.1 in) of precipitation spread over 13 days. The air carries a notable humidity level of 88%, so don’t forget to dress accordingly!
In December in Trn, the average temperature is 4°C (39°F), with a maximum that can reach 18°C (65°F) and a minimum that can drop as low as -9°C (16°F). It's advisable to pack layers and prepare for a range of weather conditions while exploring this destination.
In Trn in December, the precipitation amount is 105 mm (4.1 in) over the course of 13 days.
In Trn in December, humidity is 88%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making travel uncomfortable and necessitating extra layers to stay warm.
In Trn in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Trn, you can visit Hourly UV Index in Trn.
UV Risk Categories
Weather in Trn varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Trn, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 1°C (34°F) | 65 mm (2.6 inches) | 89% | low |
| February Weather | 4°C (40°F) | 74 mm (2.9 inches) | 83% | moderate |
| March Weather | 7°C (45°F) | 70 mm (2.8 inches) | 75% | moderate |
| April Weather | 11°C (53°F) | 86 mm (3.4 inches) | 72% | high |
| May Weather | 16°C (61°F) | 127 mm (5.0 inches) | 70% | very high |
| June Weather | 20°C (69°F) | 103 mm (4.0 inches) | 69% | very high |
| July Weather | 22°C (71°F) | 100 mm (3.9 inches) | 64% | very high |
| August Weather | 22°C (72°F) | 77 mm (3.0 inches) | 51% | very high |
| September Weather | 17°C (63°F) | 67 mm (2.6 inches) | 62% | high |
| October Weather | 12°C (54°F) | 94 mm (3.7 inches) | 81% | moderate |
| November Weather | 7°C (46°F) | 75 mm (3.0 inches) | 87% | moderate |
| December Weather | 4°C (39°F) | 105 mm (4.1 inches) | 88% | low |