Climate averages 1991–2020
Derry weather
in July.
A mild, wet month: the warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
July is a mild month in Derry: daytime highs average 17.3°C and nights cool to about 11.9°C. By daytime temperature it is the warmest month of the year.
Expect about 93 mm of rain on roughly 17 days, which makes July a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 16 h 46 min on an average July day.
The nearest other city in this atlas is Lisburn (97 km away). In July its highs average 17.7°C, about as warm as Derry, with 81 mm of rain.
Among the 143 cities listed in the United Kingdom, Derry ranks 141st of 143 for the warmest July highs and 137th of 143 for the driest July (rainfall, lowest first). The mean July high of those 143 cities is 20.0°C; Derry is 2.7°C cooler than that mean.
From July to August, average highs fall by 0.2°C to 17.1°C, and monthly rainfall rises from 93 mm to 94 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
Derry climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.1°C3.0°C | 3.0°C | 87 | 16.4 | 7.88 h |
| February | 7.5°C3.0°C | 3.0°C | 76 | 15.1 | 9.610 h |
| March | 9.0°C3.7°C | 3.7°C | 75 | 15.6 | 11.812 h |
| April | 11.1°C5.1°C | 5.1°C | 74 | 15.4 | 14.114 h |
| May | 13.8°C7.6°C | 7.6°C | 78 | 15.1 | 16.116 h |
| June | 15.9°C10.2°C | 10.2°C | 87 | 15.5 | 17.317 h |
| July, selected | 17.3°C11.9°C | 11.9°C | 93 | 16.8 | 16.817 h |
| August | 17.1°C11.9°C | 11.9°C | 94 | 16.7 | 15.015 h |
| September | 15.4°C10.4°C | 10.4°C | 75 | 14.2 | 12.813 h |
| October | 12.3°C8.0°C | 8.0°C | 88 | 15.5 | 10.511 h |
| November | 9.3°C5.4°C | 5.4°C | 90 | 16.6 | 8.58 h |
| December | 7.4°C3.4°C | 3.4°C | 90 | 15.8 | 7.37 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 · 97 kmHigh 17.7°C · Low 12.1°C · 81 mm rain
- Belfast in JulyUnited Kingdom · 99 kmHigh 17.4°C · Low 12.5°C · 81 mm rain
- Dublin in JulyIreland · 198 kmHigh 18.9°C · Low 12.9°C · 76 mm rain
- Tallaght in JulyIreland · 200 kmHigh 18.5°C · Low 12.4°C · 76 mm rain
- Paisley in JulyUnited Kingdom · 204 kmHigh 17.4°C · Low 11.3°C · 92 mm rain
- Douglas in JulyIsle of Man · 205 kmHigh 15.5°C · Low 13.5°C · 67 mm rain
- Glasgow in JulyUnited Kingdom · 215 kmHigh 17.5°C · Low 11.1°C · 92 mm rain
- East Kilbride in JulyUnited Kingdom · 215 kmHigh 16.9°C · Low 10.4°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 Derry) is explained once on the Derry year overview and on the Sources, method and limits page.