Current sea water temperature:
+48.6°F
| Minimum sea water temperature in December: | 53.2°F |
| Maximum sea water temperature in December: | 44.6°F |
| Average sea water temperature in December: | 50.1°F |
| more information | |
14 days
forecast
forecast
| Belfast |
monthly
weather
weather
| Belfast |
Sea water temperature for the last 10 days:
| December 23 | 48.6°F | December 18 | 48.9°F |
| December 22 | 48.4°F | December 17 | 49.1°F |
| December 21 | 48.4°F | December 16 | 49.1°F |
| December 20 | 48.4°F | December 15 | 49.3°F |
| December 19 | 48.6°F | December 14 | 49.3°F |
Monthly sea water temperature, °F
When is the warmest sea in Belfast?
Based on the data about daily sea water temperature for the last three years the warmest sea in Belfast was noticed in August, September and July.
Monthly Sea Temperatures in Belfast, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
The average sea water temperature in August of 2025 was 61.0°F. The highest and lowest sea temperatures during the month were 62.8°F and 58.6°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 58.7°F. The highest and lowest sea temperatures during the month were 61.0°F and 57.0°F.
Sea water temperature in July, °F
Show year:
2025
2024
2023
The average sea water temperature in July of 2025 was 59.5°F. The highest and lowest sea temperatures during the month were 62.1°F and 57.7°F.
current
weather
weather
| Belfast |
weather in
December
December
| Belfast |
Best time for vacation in Belfast
Belfast on a weather map
Places in United Kingdom:
Name
°F
24 Hours Forecast
Belfast
Local time: 23:12
December 24, wednesday
0000
45°F
W
11 mph
11 mph
0300
45°F
W
10 mph
10 mph
0600
43°F
W
8 mph
8 mph
0900
41°F
W
7 mph
7 mph
1200
45°F
W
7 mph
7 mph
1500
43°F
W
7 mph
7 mph
1800
39°F
W
6 mph
6 mph
2100
39°F
W
6 mph
6 mph
