Belfast Temperature by Month

Belfast, Antrim County, United Kingdom has an average annual maximum temperature of 13°C (55°F), with moderate seasonal shifts ranging from 9°C (48°F) in January to 19°C (66°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

Belfast experiences balanced seasonal shifts, with noticeable but moderate temperature variations. At night, minimum temperatures range from 12°C (54°F) in July to 4°C (39°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Belfast by month:

Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. July, the city's warmest month, sees 148 hours of sunshine.

The chart below shows the average temperature throughout the year:

Belfast's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

Chicago, USA averages 15°C (59°F) annually, known for extreme seasonal swings, from bitterly cold winters to warm summers.

Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Belfast, January is the coolest month, with average highs of 9°C (48°F) and humidity around 89%, considered very high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.

Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.

For more on Belfast's weather, including monthly rainfall, sunshine hours, and humidity, visit our Belfast climate page.