Climate averages 1991–2020
Belfast weather
in July.
A mild, moderately wet month: the warmest and the joint 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
July is a mild month in Belfast: daytime highs average 17.4°C and nights cool to about 12.5°C. By daytime temperature it is the warmest month of the year.
Expect about 81 mm of rain on roughly 15 days, which makes July a moderately wet month (the joint 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 16 h 41 min on an average July day.
The nearest other city in this atlas is Lisburn (11 km away). In July its highs average 17.7°C, about as warm as Belfast, with 81 mm of rain.
Among the 143 cities listed in the United Kingdom, Belfast ranks joint 139th of 143 for the warmest July highs and joint 120th of 143 for the driest July (rainfall, lowest first). The mean July high of those 143 cities is 20.0°C; Belfast is 2.5°C cooler than that mean.
From July to August, average highs fall by 0.1°C to 17.3°C, and monthly rainfall stays at 81 mm.
The annual picture
July in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Belfast climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.5°C3.9°C | 3.9°C | 77 | 14.2 | 7.98 h |
| February | 7.7°C3.8°C | 3.8°C | 63 | 12.2 | 9.710 h |
| March | 9.1°C4.4°C | 4.4°C | 62 | 13.4 | 11.812 h |
| April | 10.9°C5.9°C | 5.9°C | 65 | 13.0 | 14.014 h |
| May | 13.6°C8.2°C | 8.2°C | 70 | 14.1 | 16.016 h |
| June | 15.9°C10.9°C | 10.9°C | 75 | 13.2 | 17.217 h |
| July, selected | 17.4°C12.5°C | 12.5°C | 81 | 14.6 | 16.717 h |
| August | 17.3°C12.6°C | 12.6°C | 81 | 14.2 | 14.915 h |
| September | 15.7°C11.3°C | 11.3°C | 70 | 12.5 | 12.813 h |
| October | 12.8°C9.0°C | 9.0°C | 86 | 13.5 | 10.611 h |
| November | 9.8°C6.4°C | 6.4°C | 85 | 14.0 | 8.59 h |
| December | 7.9°C4.4°C | 4.4°C | 82 | 13.5 | 7.47 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
July in nearby cities
- Lisburn in JulyUnited Kingdom · 11 kmHigh 17.7°C · Low 12.1°C · 81 mm rain
- Derry in JulyUnited Kingdom · 99 kmHigh 17.3°C · Low 11.9°C · 93 mm rain
- Douglas in JulyIsle of Man · 106 kmHigh 15.5°C · Low 13.5°C · 67 mm rain
- Dublin in JulyIreland · 142 kmHigh 18.9°C · Low 12.9°C · 76 mm rain
- Tallaght in JulyIreland · 149 kmHigh 18.5°C · Low 12.4°C · 76 mm rain
- Paisley in JulyUnited Kingdom · 167 kmHigh 17.4°C · Low 11.3°C · 92 mm rain
- East Kilbride in JulyUnited Kingdom · 171 kmHigh 16.9°C · Low 10.4°C · 92 mm rain
- Glasgow in JulyUnited Kingdom · 176 kmHigh 17.5°C · Low 11.1°C · 92 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Belfast) is explained once on the Belfast year overview and on the Sources, method and limits page.
Lisburn lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.