January is one of the cooler months of the year in Cornwall, with average highs near -5.3°C and lows around -14.8°C (mean -10°C). It is one of the drier months, averaging 62 mm of rainfall and 92% relative humidity across the period.
January is one of the cooler months of the year in Cornwall. Across 45 years of records, the warmest January in Cornwall was 1990 — when the month averaged -4.6°C — while the coldest was 1994 at -18.2°C. Typical January days reach -5.3°C with nights near -14.8°C. The long-term trend is warming, about 1°C per decade.
January is one of the drier months in Cornwall, averaging 62 mm of rainfall. The wettest January on record was 1998 with 143 mm, while the driest was 2011 at 25 mm.
Relative humidity in Cornwall during January averages 92%. The most humid January was 1987 at 98%, and the least humid was 2025 at 81%.
January receives about 1.4 kWh/m²/day of solar energy in Cornwall. The sunniest Januarys were 2004, 2005 and 2009, among others at 1.7 kWh/m²/day, and the cloudiest were 2023 and 2024 at 1.1.
Average wind speed in Cornwall during January is 1.3 m/s. The windiest January was 1997 at 1.6 m/s, while the calmest were 2001, 2011 and 2021, among others at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -12.1°C | -10.5°C | -9.6°C | -9.3°C | -8.5°C | +3.6°C |
| Avg High | -7.0°C | -5.5°C | -5.1°C | -4.6°C | -4.1°C | +2.9°C |
| Avg Low | -17.2°C | -15.5°C | -14.2°C | -13.9°C | -12.8°C | +4.4°C |
| Avg Rain | 49 mm | 93 mm | 55 mm | 54 mm | 52 mm | +3 mm |
January temperatures in Cornwall have risen by about 5.6°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -46.2°C (1981) to a record high of 14.3°C (2008).
Rainfall in January is one of the drier months, averaging 62 mm, with a wettest year of 143 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.8°C per decade while lows rose 1.1°C per decade, narrowing the gap between day and night.
A quieter season to visit Cornwall
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Cornwall. That said, January — with days averaging -5.3°C and nights around -14.8°C (mean -10°C) and moderate rainfall (62 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | -4.9°C | -8.2°C | -11.5°C | 2.4°C | -19.0°C | 27 mm | 81% | 1.5 m/s | 1.4 |
| 2024 | -2.9°C | -6.5°C | -10.2°C | 3.8°C | -22.1°C | 69 mm | 91% | 1.3 m/s | 1.1 |
| 2023 | -2.5°C | -6.7°C | -11.0°C | 4.8°C | -20.6°C | 61 mm | 94% | 1.1 m/s | 1.1 |
| 2022 | -7.1°C | -13.4°C | -19.7°C | 2.2°C | -31.9°C | 35 mm | 87% | 1.2 m/s | 1.6 |
| 2021 | -4.2°C | -8.3°C | -12.5°C | 4.0°C | -26.8°C | 43 mm | 93% | 1 m/s | 1.5 |
| 2020 | -3.0°C | -7.6°C | -12.2°C | 10.9°C | -28.1°C | 79 mm | 94% | 1.2 m/s | 1.2 |
| 2019 | -6.9°C | -11.9°C | -16.8°C | 3.6°C | -30.3°C | 70 mm | 91% | 1.4 m/s | 1.4 |
| 2018 | -4.9°C | -9.7°C | -14.5°C | 11.5°C | -29.7°C | 71 mm | 92% | 1.5 m/s | 1.4 |
| 2017 | -1.8°C | -5.4°C | -9.0°C | 4.7°C | -23.5°C | 65 mm | 90% | 1.3 m/s | 1.4 |
| 2016 | -2.8°C | -7.5°C | -12.2°C | 5.8°C | -26.5°C | 35 mm | 91% | 1.3 m/s | 1.3 |
| 2015 | -6.6°C | -12.3°C | -18.0°C | 3.4°C | -29.7°C | 48 mm | 89% | 1.4 m/s | 1.6 |
| 2014 | -6.2°C | -10.6°C | -14.9°C | 5.4°C | -32.4°C | 48 mm | 88% | 1.5 m/s | 1.4 |
| 2013 | -2.8°C | -7.9°C | -13.0°C | 12.9°C | -26.9°C | 53 mm | 88% | 1.4 m/s | 1.5 |
| 2012 | -2.9°C | -8.2°C | -13.5°C | 3.0°C | -34.1°C | 76 mm | 92% | 1.3 m/s | 1.4 |
| 2011 | -6.3°C | -10.3°C | -14.3°C | 6.5°C | -30.5°C | 25 mm | 90% | 1 m/s | 1.3 |
| 2010 | -4.8°C | -8.9°C | -13.0°C | 9.1°C | -27.1°C | 48 mm | 94% | 1.3 m/s | 1.4 |
| 2009 | -7.7°C | -12.1°C | -16.5°C | 0.0°C | -26.3°C | 42 mm | 92% | 1.2 m/s | 1.7 |
| 2008 | -1.4°C | -5.5°C | -9.6°C | 14.3°C | -28.5°C | 59 mm | 89% | 1.4 m/s | 1.4 |
| 2007 | -3.6°C | -7.7°C | -11.8°C | 10.6°C | -26.2°C | 78 mm | 89% | 1.3 m/s | 1.5 |
| 2006 | -1.3°C | -5.5°C | -9.7°C | 5.9°C | -22.7°C | 98 mm | 94% | 1.3 m/s | 1.2 |
| 2005 | -5.6°C | -10.7°C | -15.9°C | 10.6°C | -29.5°C | 53 mm | 87% | 1.3 m/s | 1.7 |
| 2004 | -11.4°C | -15.6°C | -19.8°C | 5.7°C | -33.0°C | 32 mm | 89% | 1.5 m/s | 1.7 |
| 2003 | -8.3°C | -13.5°C | -18.7°C | -0.1°C | -32.7°C | 32 mm | 91% | 1.3 m/s | 1.7 |
| 2002 | -1.0°C | -5.1°C | -9.2°C | 5.4°C | -17.9°C | 48 mm | 93% | 1.3 m/s | 1.3 |
| 2001 | -5.2°C | -10.7°C | -16.2°C | 0.1°C | -27.1°C | 43 mm | 98% | 1 m/s | 1.5 |
| 2000 | -5.2°C | -9.7°C | -14.2°C | 10.8°C | -27.5°C | 62 mm | 85% | 1.5 m/s | 1.4 |
| 1999 | -5.6°C | -10.8°C | -16.0°C | 6.3°C | -34.4°C | 136 mm | 95% | 1.5 m/s | 1.4 |
| 1998 🌧️ | -4.7°C | -9.4°C | -14.1°C | 5.4°C | -30.7°C | 143 mm | 97% | 1.3 m/s | 1.5 |
| 1997 | -5.1°C | -10.5°C | -15.8°C | 5.0°C | -32.5°C | 92 mm | 91% | 1.6 m/s | 1.4 |
| 1996 | -7.2°C | -12.4°C | -17.6°C | 10.2°C | -35.1°C | 77 mm | 93% | 1.3 m/s | 1.4 |
| 1995 | -2.1°C | -6.2°C | -10.3°C | 14.1°C | -30.7°C | 97 mm | 94% | 1.3 m/s | 1.4 |
| 1994 ❄️ | -12.1°C | -18.2°C | -24.4°C | 0.6°C | -40.1°C | 86 mm | 98% | 1.4 m/s | 1.6 |
| 1993 | -5.0°C | -9.6°C | -14.1°C | 5.8°C | -25.4°C | 96 mm | 93% | 1.3 m/s | 1.3 |
| 1992 | -6.8°C | -11.6°C | -16.4°C | 1.7°C | -34.9°C | 72 mm | 95% | 1.2 m/s | 1.5 |
| 1991 | -6.1°C | -11.8°C | -17.5°C | 0.4°C | -37.1°C | 66 mm | 97% | 1.4 m/s | 1.4 |
| 1990 🔥 | 0.1°C | -4.6°C | -9.2°C | 6.1°C | -23.2°C | 69 mm | 91% | 1.5 m/s | 1.2 |
| 1989 | -2.6°C | -8.0°C | -13.3°C | 4.7°C | -33.8°C | 55 mm | 91% | 1.5 m/s | 1.3 |
| 1988 | -3.7°C | -8.2°C | -12.7°C | 9.2°C | -28.1°C | 27 mm | 85% | 1.5 m/s | 1.3 |
| 1987 | -6.4°C | -11.3°C | -16.3°C | 1.1°C | -32.2°C | 49 mm | 98% | 1 m/s | 1.2 |
| 1986 | -5.1°C | -10.4°C | -15.7°C | 7.0°C | -32.5°C | 68 mm | 94% | 1.4 m/s | 1.2 |
| 1985 | -9.2°C | -13.7°C | -18.1°C | 2.5°C | -28.5°C | 50 mm | 95% | 1.3 m/s | 1.6 |
| 1984 | -8.9°C | -13.9°C | -18.8°C | 0.3°C | -36.8°C | 38 mm | 98% | 1.1 m/s | 1.5 |
| 1983 | -4.3°C | -8.7°C | -13.1°C | 2.7°C | -24.6°C | 53 mm | 89% | 1.2 m/s | — |
| 1982 | -11.1°C | -17.4°C | -23.8°C | 0.5°C | -35.6°C | 75 mm | 98% | 1.3 m/s | — |
| 1981 | -12.1°C | -17.5°C | -22.8°C | 0.6°C | -46.2°C | 27 mm | 98% | 1.2 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around -5.3°C with lows near -14.8°C (mean -10°C), based on 45 years of NASA POWER data.
January averages 62 mm of rainfall in Cornwall, one of the drier months. The wettest on record was 143 mm in 1998.
The hottest January reached 14.3°C in 2008. The coldest dipped to -46.2°C in 1981.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 5.6°C. Daytime highs moved from -9.1°C to -4.3°C and overnight lows from -19.3°C to -13°C over the same span.
January is one of the cooler months of the year in Cornwall and one of the drier months, so plan for around -5.3°C daytime highs and -14.8°C at night.
Yes — January is the coldest month of the year in Cornwall, averaging -10°C.
For January in Cornwall, pack warm layers and a jacket for chilly mornings, with typical highs of -5.3°C and lows of -14.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 92% — quite humid.
Average wind speed in January is 1.3 m/s. The windiest January on record averaged 1.6 m/s (1997).
The wettest January on record was 1998 with 143 mm. On average, January sees 62 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 January, 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 January specifically, along with year-by-year records and how the month has changed over the decades.
