Measurements:
°C
°F
Belfast
38°F
NW 8 mph
Feels like: 32°F
Precip: 0%
World Resorts United Kingdom Belfast Weather

Belfast Sea Water Temperature

Current Sea Water Temperature:
+50.0°F
Maximum Sea Water Temperature in December: 53.6°F
Minimum Sea Water Temperature in December: 44.0°F
Average water temperature in December: 50.2°F

Sea Water Temperature for the Last 10 Days:

December 05 50.0°F November 30 52.4°F
December 04 50.4°F November 29 52.6°F
December 03 50.4°F November 28 53.0°F
December 02 51.6°F November 27 53.0°F
December 01 52.2°F November 26 53.0°F

When is the Warmest Sea for Belfast?

According to our data for the last three years for Belfast the highest average sea water temperature was in August, September and July.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Belfast was 62.2°F. The maximum and minimum values were 59.6°F and 64.2°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Belfast was 59.7°F. The maximum and minimum values were 57.8°F and 62.2°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Belfast was 60.6°F. The maximum and minimum values were 58.6°F and 63.4°F respectively.

Best Time to Visit Belfast
The most sunny months:
May 6 days
April 6 days
March 4 days
The most warm months:
July 64.8 °F
August 64.5 °F
June 62.2 °F
Warmest sea temperature:
August 58.7 °F
September 58.5 °F
July 57.4 °F
The most cold months:
January 43.1 °F
February 45.0 °F
December 45.1 °F
The most rainy months:
July 7 days
June 6 days
August 6 days
The most windy months:
February 13 mph
December 13 mph
January 12 mph

Belfast on the Weather Map

United Kingdom Resorts:
NAME
Bath +40
Belfast +38
Bournemouth +48
Brighton +46
Bristol +42
Edinburgh +40
Gibraltar +56
Glasgow +36
Liverpool +40
London +38
Middlesbrough +40
Plymouth +48
Scarborough +38
Torquay +42
York +38
24 Hours Weather Forecast
Belfast
Local time: 09:03
05 dec, friday
1200 46°F
NW
24 mph
1500 42°F
NW
30 mph
1800 50°F
NW
21 mph
2100 48°F
N
9 mph
06 dec, saturday
0000 46°F
N
10 mph
0300 44°F
N
8 mph
0600 44°F
N
7 mph
0900 44°F
NE
7 mph