July is one of the warmer months of the year in Derry, with average highs near 16.7°C and lows around 11.2°C (mean 14°C). It is about average for rainfall, averaging 103 mm of rainfall and 86% relative humidity across the period.
July is one of the warmer months of the year in Derry. Across 45 years of records, the warmest July in Derry was 2013 — when the month averaged 15.9°C — while the coldest was 2015 at 12.4°C. Typical July days reach 16.7°C with nights near 11.2°C. The long-term July temperature trend is broadly flat.
July is about average for rainfall in Derry, averaging 103 mm of rainfall. The wettest July on record was 2023 with 189 mm, while the driest was 1982 at 43 mm.
Relative humidity in Derry during July averages 86%. The most humid July was 1987 at 88%, and the least humid was 1982 at 84%.
July receives about 4.4 kWh/m²/day of solar energy in Derry. The sunniest July was 2013 at 5.3 kWh/m²/day, and the cloudiest was 2002 at 3.6.
Average wind speed in Derry during July is 3.7 m/s. The windiest July was 1993 at 4.6 m/s, while the calmest was 2021 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.9°C | 14.0°C | 13.9°C | 14.0°C | 14.3°C | +0.4°C |
| Avg High | 16.8°C | 16.8°C | 16.6°C | 16.7°C | 17.1°C | +0.3°C |
| Avg Low | 11.0°C | 11.3°C | 11.2°C | 11.2°C | 11.5°C | +0.5°C |
| Avg Rain | 89 mm | 101 mm | 101 mm | 117 mm | 106 mm | +17 mm |
July temperatures in Derry have risen by about 0.5°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 6.5°C (1984) to a record high of 25.2°C (2022).
Rainfall in July is about average for rainfall, averaging 103 mm, with a wettest year of 189 mm.
One of the best times to visit Derry
July is one of the best times to visit Derry. Expect days averaging 16.7°C and nights around 11.2°C (mean 14°C) — warmer than Derry's yearly average — with higher rainfall (103 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 18.1°C | 15.2°C | 12.3°C | 24.8°C | 8.9°C | 84 mm | 87% | 3.7 m/s | 4.5 |
| 2024 | 16.2°C | 13.4°C | 10.6°C | 19.7°C | 8.8°C | 87 mm | 86% | 3.5 m/s | 4.2 |
| 2023 🌧️ | 16.4°C | 14.1°C | 11.7°C | 21.3°C | 9.2°C | 189 mm | 86% | 4.2 m/s | 4 |
| 2022 | 17.7°C | 14.7°C | 11.8°C | 25.2°C | 10.1°C | 75 mm | 86% | 3.4 m/s | 4.4 |
| 2021 | 18.7°C | 15.6°C | 12.4°C | 24.6°C | 9.6°C | 68 mm | 87% | 2.4 m/s | 4.8 |
| 2020 | 15.2°C | 12.8°C | 10.4°C | 19.6°C | 8.6°C | 136 mm | 86% | 4.1 m/s | 3.9 |
| 2019 | 17.3°C | 14.7°C | 12.1°C | 22.6°C | 8.6°C | 131 mm | 88% | 3.7 m/s | 4.4 |
| 2018 | 17.8°C | 14.7°C | 11.7°C | 22.1°C | 9.0°C | 87 mm | 85% | 3.2 m/s | 4.8 |
| 2017 | 16.4°C | 13.5°C | 10.5°C | 21.5°C | 7.4°C | 136 mm | 85% | 3.9 m/s | 4.7 |
| 2016 | 16.2°C | 13.6°C | 11.0°C | 23.5°C | 8.9°C | 136 mm | 87% | 3.8 m/s | 4.2 |
| 2015 ❄️ | 15.1°C | 12.4°C | 9.7°C | 19.7°C | 6.9°C | 155 mm | 86% | 4 m/s | 4 |
| 2014 | 17.8°C | 15.0°C | 12.1°C | 23.5°C | 8.6°C | 83 mm | 85% | 3.4 m/s | 4.6 |
| 2013 🔥 | 19.4°C | 15.9°C | 12.4°C | 24.0°C | 9.3°C | 75 mm | 86% | 2.8 m/s | 5.3 |
| 2012 | 15.1°C | 12.7°C | 10.2°C | 19.5°C | 7.4°C | 116 mm | 87% | 3.6 m/s | 4 |
| 2011 | 16.0°C | 13.2°C | 10.3°C | 19.4°C | 8.1°C | 80 mm | 85% | 3.2 m/s | 4.5 |
| 2010 | 16.3°C | 13.9°C | 11.5°C | 19.5°C | 9.0°C | 171 mm | 86% | 4.5 m/s | 4.4 |
| 2009 | 16.6°C | 14.0°C | 11.4°C | 21.5°C | 8.1°C | 148 mm | 86% | 3.9 m/s | 4.5 |
| 2008 | 16.9°C | 14.2°C | 11.5°C | 21.1°C | 8.0°C | 137 mm | 87% | 4.2 m/s | 4 |
| 2007 | 15.7°C | 13.2°C | 10.7°C | 18.2°C | 8.4°C | 125 mm | 87% | 3.5 m/s | 4.4 |
| 2006 | 19.1°C | 15.8°C | 12.5°C | 24.0°C | 8.8°C | 78 mm | 85% | 3.3 m/s | 5 |
| 2005 | 16.6°C | 13.9°C | 11.2°C | 24.0°C | 8.7°C | 56 mm | 88% | 3.4 m/s | 4.3 |
| 2004 | 15.7°C | 13.0°C | 10.4°C | 18.7°C | 8.0°C | 96 mm | 86% | 3.8 m/s | 4.3 |
| 2003 | 17.6°C | 14.9°C | 12.2°C | 22.8°C | 10.4°C | 105 mm | 88% | 3.7 m/s | 3.8 |
| 2002 | 14.9°C | 12.6°C | 10.3°C | 20.8°C | 8.2°C | 112 mm | 88% | 3.6 m/s | 3.6 |
| 2001 | 15.9°C | 13.3°C | 10.6°C | 20.6°C | 7.2°C | 87 mm | 87% | 3.7 m/s | 4 |
| 2000 | 16.5°C | 13.7°C | 11.0°C | 21.4°C | 8.3°C | 62 mm | 87% | 3.1 m/s | 4.8 |
| 1999 | 17.7°C | 14.6°C | 11.5°C | 23.1°C | 8.7°C | 96 mm | 87% | 3.6 m/s | 4.9 |
| 1998 | 15.2°C | 13.0°C | 10.8°C | 18.9°C | 8.7°C | 147 mm | 88% | 4.5 m/s | 4.2 |
| 1997 | 17.2°C | 14.3°C | 11.4°C | 21.3°C | 8.3°C | 119 mm | 87% | 3.6 m/s | 4 |
| 1996 | 16.1°C | 13.4°C | 10.8°C | 20.9°C | 7.6°C | 80 mm | 86% | 3.7 m/s | 4.4 |
| 1995 | 17.9°C | 15.0°C | 12.2°C | 21.9°C | 9.4°C | 112 mm | 86% | 3.8 m/s | 4.4 |
| 1994 | 17.1°C | 14.2°C | 11.3°C | 19.8°C | 9.3°C | 77 mm | 86% | 3.3 m/s | 4.6 |
| 1993 | 14.7°C | 12.5°C | 10.3°C | 18.4°C | 7.1°C | 110 mm | 87% | 4.6 m/s | 4.3 |
| 1992 | 16.4°C | 13.7°C | 10.9°C | 19.8°C | 9.0°C | 94 mm | 85% | 4 m/s | 4.3 |
| 1991 | 17.8°C | 14.9°C | 12.0°C | 21.7°C | 9.5°C | 102 mm | 87% | 3.8 m/s | 4.4 |
| 1990 | 17.5°C | 14.4°C | 11.3°C | 22.5°C | 7.1°C | 78 mm | 85% | 4.3 m/s | 4.8 |
| 1989 | 18.5°C | 15.2°C | 11.9°C | 23.4°C | 8.1°C | 48 mm | 84% | 3.4 m/s | 5.2 |
| 1988 | 14.8°C | 12.5°C | 10.2°C | 17.6°C | 8.0°C | 140 mm | 86% | 4.4 m/s | 4.3 |
| 1987 | 16.5°C | 13.7°C | 10.9°C | 19.9°C | 7.4°C | 100 mm | 88% | 4 m/s | 3.9 |
| 1986 | 15.7°C | 13.0°C | 10.4°C | 21.2°C | 8.2°C | 100 mm | 86% | 4 m/s | 3.9 |
| 1985 | 15.9°C | 13.2°C | 10.6°C | 20.0°C | 7.4°C | 153 mm | 87% | 4.1 m/s | 4 |
| 1984 | 17.3°C | 14.2°C | 11.1°C | 21.2°C | 6.5°C | 72 mm | 85% | 3.2 m/s | 4.6 |
| 1983 | 19.3°C | 15.8°C | 12.2°C | 24.6°C | 8.8°C | 45 mm | 85% | 2.9 m/s | — |
| 1982 | 17.4°C | 14.2°C | 10.9°C | 21.3°C | 9.0°C | 43 mm | 84% | 3.1 m/s | — |
| 1981 | 15.4°C | 13.0°C | 10.6°C | 18.9°C | 8.5°C | 104 mm | 87% | 4.3 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 16.7°C with lows near 11.2°C (mean 14°C), based on 45 years of NASA POWER data.
July averages 103 mm of rainfall in Derry, about average for rainfall. The wettest on record was 189 mm in 2023.
The hottest July reached 25.2°C in 2022. The coldest dipped to 6.5°C in 1984.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 0.5°C. Daytime highs moved from 17.1°C to 17.4°C and overnight lows from 11.1°C to 11.8°C over the same span.
July is one of the warmer months of the year in Derry and about average for rainfall, so plan for around 16.7°C daytime highs and 11.2°C at night.
Not quite — July is the 12th coolest month in Derry, averaging 14°C.
For July in Derry, pack light layers you can adjust through the day, with typical highs of 16.7°C and lows of 11.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in July averages 86% — quite humid.
Average wind speed in July is 3.7 m/s. The windiest July on record averaged 4.6 m/s (1993).
The wettest July on record was 2023 with 189 mm. On average, July sees 103 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Derry behaves each July, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for July specifically, along with year-by-year records and how the month has changed over the decades.
