Belfast weather in December
December in Belfast: cold, rainy, with clean air — a fair time to visit.
#12 of 12 months in Belfast · #685 of 897 destinations to visit in December · comfort 56/100 (tier D)
Updated June 2026 · climate normals from ERA5 reanalysis
Traveller notes on Belfast in December
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Belfast climate normals — December
| Daytime high | 8°C / 47°F | 🧥 cold |
|---|---|---|
| Nighttime low | 5°C / 41°F | |
| Rainfall | 94 mm / 3.7 in | 🌧 rainy |
| Rainy days | 16 days | |
| Humidity | 86% | 💦 very humid |
| Dew point | 4°C / 40°F | |
| Sunshine | 2.8 h/day | |
| Daylight | 7.4 h | |
| Wind | 24 km/h / 15 mph | |
| Snowfall | 0.4 cm / 0.2 in | |
| Air quality (US AQI) | 33 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Belfast in December — FAQ
- Is December a good time to visit Belfast?
- December in Belfast: cold, rainy, with clean air — a fair time to visit. It ranks #12 of 12 months for Belfast on SeasonMap's comfort score (56/100).
- What is the weather like in Belfast in December?
- In December, Belfast averages a daily high of 8.2°C and a low of 5.1°C, with about 93.6 mm of rain over roughly 16 rainy days.
- What is the air quality in Belfast in December?
- Belfast has a mean US Air Quality Index of about 33 in December.