July is one of the warmer months of the year in Cornwall, with average highs near 26°C and lows around 15.7°C (mean 20.9°C). It is a relatively wet time of year, averaging 97 mm of rainfall and 78% relative humidity across the period.
July is one of the warmer months of the year in Cornwall. Across 45 years of records, the warmest July in Cornwall was 2020 — when the month averaged 24.6°C — while the coldest was 1992 at 17.8°C. Typical July days reach 26°C with nights near 15.7°C. The long-term trend is warming, about 0.6°C per decade.
July is a relatively wet time of year in Cornwall, averaging 97 mm of rainfall. The wettest July on record was 2009 with 167 mm, while the driest were 2001 and 2012 at 51 mm.
Relative humidity in Cornwall during July averages 78%. The most humid July was 2009 at 84%, and the least humid was 2022 at 65%.
July receives about 5.8 kWh/m²/day of solar energy in Cornwall. The sunniest Julys were 1989 and 2018 at 6.6 kWh/m²/day, and the cloudiest was 2009 at 4.9.
Average wind speed in Cornwall during July is 0.4 m/s. The windiest Julys were 1982 and 1996 at 0.5 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 20.1°C | 20.2°C | 20.3°C | 21.6°C | 22.6°C | +2.5°C |
| Avg High | 25.3°C | 25.2°C | 25.0°C | 26.9°C | 28.3°C | +3°C |
| Avg Low | 14.9°C | 15.2°C | 15.4°C | 16.3°C | 17.1°C | +2.2°C |
| Avg Rain | 89 mm | 103 mm | 114 mm | 88 mm | 87 mm | -2 mm |
July temperatures in Cornwall have risen by about 2.4°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 7.1°C (1992) to a record high of 36.9°C (2018).
Rainfall in July is a relatively wet time of year, averaging 97 mm, with a wettest year of 167 mm.
One of the best times to visit Cornwall
July is one of the best times to visit Cornwall. Expect days averaging 26°C and nights around 15.7°C (mean 20.9°C) — warmer than Cornwall's yearly average — with higher rainfall (97 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 | 29.4°C | 23.4°C | 17.5°C | 35.0°C | 10.7°C | 52 mm | 69% | 0.4 m/s | 5.9 |
| 2024 | 27.8°C | 22.5°C | 17.3°C | 35.6°C | 11.7°C | 118 mm | 77% | 0.4 m/s | 5.8 |
| 2023 | 27.9°C | 22.5°C | 17.2°C | 33.9°C | 10.1°C | 109 mm | 76% | 0.4 m/s | 5.3 |
| 2022 | 28.2°C | 22.2°C | 16.1°C | 32.6°C | 10.0°C | 65 mm | 65% | 0.4 m/s | 6.1 |
| 2021 | 25.9°C | 20.6°C | 15.4°C | 32.6°C | 10.2°C | 110 mm | 73% | 0.4 m/s | 5.3 |
| 2020 🔥 | 30.3°C | 24.6°C | 18.9°C | 36.3°C | 15.5°C | 66 mm | 70% | 0.4 m/s | 6 |
| 2019 | 27.4°C | 22.3°C | 17.2°C | 32.1°C | 13.0°C | 56 mm | 80% | 0.4 m/s | 6.4 |
| 2018 | 27.6°C | 22.3°C | 17.1°C | 36.9°C | 10.4°C | 108 mm | 78% | 0.4 m/s | 6.6 |
| 2017 | 24.8°C | 20.3°C | 15.9°C | 30.0°C | 10.8°C | 167 mm | 82% | 0.4 m/s | 5.7 |
| 2016 | 28.2°C | 22.3°C | 16.4°C | 33.2°C | 12.7°C | 65 mm | 69% | 0.4 m/s | 5.9 |
| 2015 | 27.0°C | 21.1°C | 15.2°C | 34.1°C | 9.5°C | 70 mm | 73% | 0.4 m/s | 6 |
| 2014 | 24.5°C | 19.7°C | 14.9°C | 30.4°C | 11.3°C | 116 mm | 80% | 0.4 m/s | 5.4 |
| 2013 | 26.4°C | 21.4°C | 16.4°C | 32.3°C | 9.6°C | 95 mm | 81% | 0.4 m/s | 6 |
| 2012 | 28.5°C | 22.5°C | 16.4°C | 33.8°C | 11.6°C | 51 mm | 68% | 0.4 m/s | 6.5 |
| 2011 | 26.8°C | 21.8°C | 16.8°C | 31.8°C | 12.7°C | 64 mm | 79% | 0.4 m/s | 6.5 |
| 2010 | 27.6°C | 22.4°C | 17.1°C | 32.8°C | 9.9°C | 93 mm | 77% | 0.4 m/s | 6 |
| 2009 🌧️ | 23.3°C | 19.1°C | 15.0°C | 28.7°C | 9.7°C | 167 mm | 84% | 0.4 m/s | 4.9 |
| 2008 | 24.9°C | 20.4°C | 15.8°C | 29.3°C | 11.4°C | 113 mm | 83% | 0.4 m/s | 5.3 |
| 2007 | 24.3°C | 19.6°C | 14.8°C | 30.9°C | 8.1°C | 154 mm | 82% | 0.4 m/s | 5.6 |
| 2006 | 26.5°C | 21.6°C | 16.8°C | 30.3°C | 11.8°C | 96 mm | 82% | 0.4 m/s | 5.8 |
| 2005 | 26.9°C | 21.7°C | 16.4°C | 34.3°C | 10.3°C | 120 mm | 80% | 0.4 m/s | 6.1 |
| 2004 | 25.2°C | 20.5°C | 15.8°C | 28.8°C | 10.2°C | 118 mm | 82% | 0.4 m/s | 5.3 |
| 2003 | 25.7°C | 20.8°C | 15.9°C | 30.5°C | 12.6°C | 129 mm | 81% | 0.4 m/s | 5.4 |
| 2002 | 25.7°C | 20.7°C | 15.6°C | 31.3°C | 9.8°C | 82 mm | 80% | 0.4 m/s | 6.3 |
| 2001 | 24.6°C | 19.4°C | 14.1°C | 31.6°C | 7.5°C | 51 mm | 74% | 0.4 m/s | 5.9 |
| 2000 | 23.3°C | 18.7°C | 14.2°C | 29.1°C | 9.5°C | 109 mm | 82% | 0.4 m/s | 5.5 |
| 1999 | 27.7°C | 22.3°C | 16.8°C | 32.3°C | 11.0°C | 127 mm | 75% | 0.4 m/s | 6 |
| 1998 | 24.9°C | 20.2°C | 15.5°C | 29.4°C | 10.8°C | 114 mm | 81% | 0.4 m/s | 5.9 |
| 1997 | 24.4°C | 19.1°C | 13.8°C | 28.9°C | 9.1°C | 97 mm | 80% | 0.4 m/s | 6 |
| 1996 | 23.6°C | 19.0°C | 14.4°C | 27.2°C | 9.8°C | 154 mm | 82% | 0.5 m/s | 5.2 |
| 1995 | 27.0°C | 21.6°C | 16.2°C | 31.4°C | 9.4°C | 105 mm | 76% | 0.4 m/s | 5.4 |
| 1994 | 25.9°C | 21.0°C | 16.2°C | 33.8°C | 10.4°C | 74 mm | 83% | 0.4 m/s | 5.6 |
| 1993 | 25.5°C | 20.8°C | 16.2°C | 30.4°C | 10.3°C | 69 mm | 82% | 0.4 m/s | 5.7 |
| 1992 ❄️ | 22.5°C | 17.8°C | 13.2°C | 27.9°C | 7.1°C | 145 mm | 81% | 0.4 m/s | 5.9 |
| 1991 | 25.4°C | 20.1°C | 14.7°C | 30.3°C | 9.3°C | 62 mm | 78% | 0.4 m/s | 6.1 |
| 1990 | 25.2°C | 20.2°C | 15.2°C | 30.4°C | 9.1°C | 87 mm | 78% | 0.4 m/s | 5.9 |
| 1989 | 25.8°C | 20.2°C | 14.7°C | 30.9°C | 10.5°C | 69 mm | 78% | 0.4 m/s | 6.6 |
| 1988 | 27.1°C | 21.4°C | 15.8°C | 32.9°C | 8.5°C | 102 mm | 77% | 0.4 m/s | 5.6 |
| 1987 | 26.0°C | 20.9°C | 15.8°C | 30.7°C | 8.9°C | 128 mm | 79% | 0.4 m/s | 5.6 |
| 1986 | 24.0°C | 19.1°C | 14.2°C | 30.3°C | 8.8°C | 160 mm | 82% | 0.4 m/s | 5.7 |
| 1985 | 24.2°C | 19.2°C | 14.1°C | 28.9°C | 10.3°C | 94 mm | 79% | 0.4 m/s | 6.1 |
| 1984 | 24.9°C | 19.8°C | 14.7°C | 27.9°C | 9.6°C | 54 mm | 79% | 0.4 m/s | 5.1 |
| 1983 | 25.5°C | 20.2°C | 15.0°C | 29.9°C | 8.2°C | 60 mm | 80% | 0.4 m/s | — |
| 1982 | 24.9°C | 19.4°C | 14.0°C | 29.4°C | 7.9°C | 60 mm | 78% | 0.5 m/s | — |
| 1981 | 25.3°C | 20.4°C | 15.4°C | 30.2°C | 9.2°C | 74 mm | 81% | 0.4 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 26°C with lows near 15.7°C (mean 20.9°C), based on 45 years of NASA POWER data.
July averages 97 mm of rainfall in Cornwall, a relatively wet time of year. The wettest on record was 167 mm in 2009.
The hottest July reached 36.9°C in 2018. The coldest dipped to 7.1°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 2.4°C. Daytime highs moved from 25°C to 27.8°C and overnight lows from 14.6°C to 16.7°C over the same span.
July is one of the warmer months of the year in Cornwall and a relatively wet time of year, so plan for around 26°C daytime highs and 15.7°C at night.
Not quite — July is the 12th coolest month in Cornwall, averaging 20.9°C.
For July in Cornwall, pack light layers you can adjust through the day, with typical highs of 26°C and lows of 15.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in July averages 78% — quite humid.
Average wind speed in July is 0.4 m/s. The windiest July on record averaged 0.5 m/s (1982).
The wettest July on record was 2009 with 167 mm. On average, July sees 97 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 Cornwall 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.
