Belfast Weather in August

August in Belfast sees daytime temperatures around 19°C (66°F) and lows of 12°C (54°F) at night. With around 92 mm (3.6 in) of rainfall expected, it's worth packing a rain jacket.

Rainfall in Belfast in August

You can expect rain on roughly 17 days based on historical data, averaging 92 mm (3.6 in) for the month. The rainfall pattern this month is fairly balanced. Showers tend to be moderate rather than extreme.

Temperature in Belfast in August

If you're visiting Belfast in August, expect highs of 19°C (66°F) and overnight lows around 12°C (54°F). During August, you'll experience the summer season. Conditions are often most pleasant around the middle of the day. At 12°C (54°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping. On average, it sees the highest temps of the year.

Sunshine in Belfast in August

The month brings about 139 hours of sunlight, offering a comfortable mix of sun and overcast.

Wind Speed in Belfast in August

August sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.

Average water temperature in August

With water at 13°C (55°F), it's on the cooler side. Keen swimmers won't be put off, but those who prefer warm water may find it less enjoyable.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. July and August typically offer the best weather for Belfast.

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For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.

Belfast Temperature in August

Min Temperature 12°C (54°F)  

Max Temperature 19°C (66°F)  

Water Temperature 13°C (55°F) *  

Chance of Rain 58%  

Precipitation 92 mm (3.6 in)  

Rainy days 17 days  

Humidity 89% *  

Windspeed 4 m/s (8 knots) *  

Sunshine 139 hours *  

Percentage Sunshine 29% *  

* Data from: Belfast, Ireland (19 KM, 12 Miles).

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Belfast typically stay consistent throughout August, with daily highs averaging around 19°C (66°F). Nights are cool, with lows around 12°C (54°F).

Average temperatures in August

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in August

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

‹ January February March April May June July August September October November December ›

Historical weather for Belfast in August

Browse day-by-day weather records for Belfast spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

‹ 2026 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 ›

‹ January February March April May June July August September October November December ›

Belfast historical weather extremes in August

According to our 49 years of weather records for Belfast, the following extremes were recorded between 1976 and 2025.

• The hottest August day on record in Belfast reached 29°C (84°F) (August 21, 1995).
• The lowest daytime temperature in August was 12°C (54°F), recorded on August 22, 1986.
• Nighttime temperatures dropped to 3°C (37°F) on August 24, 1986, marking the coldest August night on record.

What to Wear in Belfast in August

Pleasant temperatures in August mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. The water temperature sits at about 13°C (55°F), which is too chilly for most people to enjoy swimming. Leave the swimsuit at home unless you love cold water. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Belfast in August

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

6/10

Cycling

9/10

Walking

9/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.

More climate data for Belfast

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Belfast climate overview or explore weather in the United Kingdom.