Belfast Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Belfast, County Antrim, Ireland. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Now, let's explore all the details to give you a full picture.

Generally, Belfast receives mid-range precipitation levels, with 974 mm (38 in) annually.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Precipitation levels in Belfast remain relatively steady throughout the year. August has the most rain, with 91 mm (3.6 in) over 19 days. In March, this drops slightly to 69 mm (2.7 in), making the city's climate fairly predictable.

August, the wettest month, has a maximum daytime temperature of 19°C (66°F). The city receives 139 hours of sunshine in this period. During the driest month March you can expect a temperature of 11°C (52°F). For more detailed insights into the city's temperatures, visit our Belfast Temperature page.

Annual Rainfall in Ireland: City Comparison

The map below shows the annual precipitation across Ireland. You can also select the different months in case you are interested in a specific month.

Annual

Annual

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Legend

heavy rainfall

high

moderate

low

almost none

Heavy annual rainfall has been defined as more than 1000 mm (39 in) precipitation. High: 600 mm (24 in) to 1000 mm (39 in). Moderate: 250 mm (9.8 in) to 600 mm (24 in). Low: less than 250 mm (9.8 in).

Belfast vs World: Rainfall Compared

Belfast's average annual precipitation is 974 mm (38 in). Let's compare this to some popular worldwide tourist destinations:

Seville, Spain, experiences 541 mm (21 in) of rainfall annually, with wet winters and dry summers typical of southern Spain.

Osaka, Japan, experiences 1507 mm (59 in) of rainfall annually, spread across the year with wetter summers.

In Tokyo, Japan, the average annual precipitation is 1528 mm (60 in), with significant summer rains due to typhoon season.

Singapore, situated near the equator, gets 2581 mm (102 in) of rainfall annually, with no distinct dry season and consistent monthly precipitation.

How is Precipitation Measured?

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.

Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.

Interesting weather facts

"Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
The greatest snowfall recorded was on Mt. Rainier, Washington State, USA—over 31.5 meters (103 feet) fell during the winter of 1972.

For more detailed information about Belfast's weather, including sunshine hours, humidity levels, and temperature data, visit our Belfast Climate page.

Current rainfall in Belfast

10-Day Forecast