December is one of the cooler months of the year in Penzance, with average highs near 11°C and lows around 9.3°C (mean 10.2°C). It is a relatively wet time of year, averaging 120 mm of rainfall and 83% relative humidity across the period.
December is one of the cooler months of the year in Penzance. Across 45 years of records, the warmest December in Penzance was 2015 — when the month averaged 12.4°C — while the coldest was 2010 at 7.2°C. Typical December days reach 11°C with nights near 9.3°C. The long-term trend is warming, about 0.2°C per decade.
December is a relatively wet time of year in Penzance, averaging 120 mm of rainfall. The wettest December on record was 1999 with 221 mm, while the driest was 1991 at 34 mm.
Relative humidity in Penzance during December averages 83%. The most humid December was 1987 at 88%, and the least humid was 1990 at 79%.
December receives about 0.7 kWh/m²/day of solar energy in Penzance. The sunniest Decembers were 2001 and 2010 at 0.8 kWh/m²/day, and the cloudiest were 2015 and 2018 at 0.5.
Average wind speed in Penzance during December is 7.9 m/s. The windiest December was 2015 at 9.9 m/s, while the calmest was 2016 at 5.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.0°C | 9.7°C | 10.1°C | 10.5°C | 10.6°C | +0.6°C |
| Avg High | 10.9°C | 10.6°C | 10.9°C | 11.2°C | 11.4°C | +0.5°C |
| Avg Low | 9.1°C | 8.8°C | 9.3°C | 9.7°C | 10.0°C | +0.9°C |
| Avg Rain | 121 mm | 121 mm | 102 mm | 122 mm | 143 mm | +22 mm |
December temperatures in Penzance have risen by about 1.1°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 0.7°C (1996) to a record high of 15.6°C (1985).
Rainfall in December is a relatively wet time of year, averaging 120 mm, with a wettest year of 221 mm.
A quieter season to visit Penzance
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Penzance. That said, December — with days averaging 11°C and nights around 9.3°C (mean 10.2°C) and higher rainfall (120 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 | 11.7°C | 10.8°C | 10.0°C | 14.4°C | 6.6°C | 183 mm | 83% | 8.2 m/s | — |
| 2024 | 11.7°C | 10.9°C | 10.2°C | 14.0°C | 8.7°C | 120 mm | 85% | 7.6 m/s | 0.6 |
| 2023 | 12.1°C | 11.4°C | 10.8°C | 13.6°C | 6.8°C | 143 mm | 85% | 8.7 m/s | 0.6 |
| 2022 | 10.4°C | 9.6°C | 8.8°C | 13.8°C | 5.4°C | 136 mm | 82% | 7.4 m/s | 0.7 |
| 2021 | 11.7°C | 11.1°C | 10.5°C | 13.2°C | 8.4°C | 92 mm | 87% | 8.2 m/s | 0.6 |
| 2020 | 10.9°C | 10.1°C | 9.4°C | 13.1°C | 6.7°C | 183 mm | 82% | 8.9 m/s | 0.7 |
| 2019 | 11.2°C | 10.4°C | 9.6°C | 13.0°C | 7.4°C | 125 mm | 82% | 8.2 m/s | 0.7 |
| 2018 | 12.0°C | 11.3°C | 10.7°C | 13.6°C | 8.8°C | 178 mm | 87% | 7.5 m/s | 0.5 |
| 2017 | 11.1°C | 10.2°C | 9.2°C | 13.4°C | 6.2°C | 134 mm | 82% | 8 m/s | 0.7 |
| 2016 | 11.8°C | 11.3°C | 10.8°C | 13.1°C | 8.9°C | 58 mm | 85% | 5.6 m/s | 0.6 |
| 2015 🔥 | 13.1°C | 12.4°C | 11.6°C | 14.2°C | 9.1°C | 163 mm | 86% | 9.9 m/s | 0.5 |
| 2014 | 11.1°C | 10.3°C | 9.6°C | 12.8°C | 6.5°C | 72 mm | 80% | 8 m/s | 0.7 |
| 2013 | 11.6°C | 10.6°C | 9.6°C | 12.9°C | 7.7°C | 108 mm | 80% | 8.1 m/s | 0.6 |
| 2012 | 11.0°C | 10.2°C | 9.4°C | 12.7°C | 7.0°C | 189 mm | 82% | 8.3 m/s | 0.6 |
| 2011 | 11.5°C | 10.6°C | 9.8°C | 13.1°C | 7.9°C | 127 mm | 81% | 9.1 m/s | 0.6 |
| 2010 ❄️ | 7.9°C | 7.2°C | 6.5°C | 10.9°C | 3.3°C | 61 mm | 79% | 6.5 m/s | 0.8 |
| 2009 | 10.0°C | 9.1°C | 8.2°C | 12.7°C | 4.5°C | 116 mm | 82% | 7.3 m/s | 0.7 |
| 2008 | 10.1°C | 9.5°C | 8.8°C | 11.9°C | 6.7°C | 82 mm | 82% | 7.4 m/s | 0.7 |
| 2007 | 11.6°C | 10.8°C | 10.0°C | 14.3°C | 6.1°C | 89 mm | 80% | 8.8 m/s | 0.7 |
| 2006 | 11.9°C | 11.1°C | 10.3°C | 14.2°C | 7.7°C | 104 mm | 81% | 8.6 m/s | 0.6 |
| 2005 | 10.5°C | 9.7°C | 9.0°C | 12.0°C | 4.9°C | 92 mm | 80% | 6.6 m/s | 0.7 |
| 2004 | 11.4°C | 10.5°C | 9.7°C | 13.3°C | 6.5°C | 65 mm | 82% | 6.7 m/s | 0.6 |
| 2003 | 11.0°C | 10.1°C | 9.2°C | 12.7°C | 6.7°C | 111 mm | 83% | 7.7 m/s | 0.6 |
| 2002 | 11.0°C | 10.3°C | 9.7°C | 13.5°C | 4.8°C | 139 mm | 86% | 8 m/s | 0.6 |
| 2001 | 10.5°C | 9.6°C | 8.6°C | 13.8°C | 5.8°C | 61 mm | 80% | 7.4 m/s | 0.8 |
| 2000 | 10.7°C | 10.0°C | 9.2°C | 13.4°C | 5.1°C | 159 mm | 85% | 8.7 m/s | 0.7 |
| 1999 🌧️ | 11.2°C | 10.2°C | 9.2°C | 13.2°C | 5.8°C | 221 mm | 81% | 9.6 m/s | 0.6 |
| 1998 | 11.2°C | 10.2°C | 9.3°C | 13.4°C | 5.3°C | 154 mm | 85% | 7.6 m/s | 0.6 |
| 1997 | 11.5°C | 10.7°C | 9.8°C | 14.3°C | 5.4°C | 132 mm | 82% | 8.1 m/s | 0.7 |
| 1996 | 9.1°C | 8.3°C | 7.5°C | 12.7°C | 0.7°C | 62 mm | 84% | 7 m/s | 0.6 |
| 1995 | 10.4°C | 9.4°C | 8.4°C | 13.4°C | 3.3°C | 92 mm | 85% | 7.2 m/s | 0.6 |
| 1994 | 11.8°C | 11.0°C | 10.2°C | 13.9°C | 7.1°C | 142 mm | 84% | 8.5 m/s | 0.7 |
| 1993 | 10.8°C | 9.8°C | 8.7°C | 12.7°C | 6.4°C | 176 mm | 82% | 9.8 m/s | 0.7 |
| 1992 | 10.0°C | 9.1°C | 8.2°C | 12.7°C | 6.2°C | 105 mm | 83% | 7 m/s | 0.7 |
| 1991 | 10.4°C | 9.7°C | 9.0°C | 12.2°C | 6.3°C | 34 mm | 81% | 6.9 m/s | 0.7 |
| 1990 | 9.9°C | 8.9°C | 8.0°C | 12.4°C | 5.4°C | 90 mm | 79% | 7.9 m/s | 0.7 |
| 1989 | 11.4°C | 10.6°C | 9.7°C | 13.4°C | 7.0°C | 159 mm | 84% | 8.5 m/s | 0.7 |
| 1988 | 11.5°C | 10.8°C | 10.1°C | 13.4°C | 8.4°C | 53 mm | 85% | 5.8 m/s | 0.6 |
| 1987 | 10.6°C | 10.0°C | 9.4°C | 13.1°C | 5.9°C | 103 mm | 88% | 8.5 m/s | 0.7 |
| 1986 | 10.9°C | 10.0°C | 9.1°C | 13.4°C | 6.7°C | 162 mm | 83% | 8.7 m/s | 0.7 |
| 1985 | 11.2°C | 10.4°C | 9.7°C | 15.6°C | 4.6°C | 118 mm | 85% | 7.4 m/s | 0.7 |
| 1984 | 10.9°C | 10.0°C | 9.0°C | 12.4°C | 5.9°C | 104 mm | 83% | 6.4 m/s | 0.7 |
| 1983 | 11.2°C | 10.3°C | 9.5°C | 12.9°C | 6.7°C | 99 mm | 82% | 7.6 m/s | — |
| 1982 | 10.3°C | 9.4°C | 8.4°C | 13.3°C | 5.7°C | 131 mm | 82% | 8 m/s | — |
| 1981 | 9.8°C | 8.6°C | 7.3°C | 11.7°C | 3.4°C | 159 mm | 81% | 7.4 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 11°C with lows near 9.3°C (mean 10.2°C), based on 45 years of NASA POWER data.
December averages 120 mm of rainfall in Penzance, a relatively wet time of year. The wettest on record was 221 mm in 1999.
The hottest December reached 15.6°C in 1985. The coldest dipped to 0.7°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.1°C. Daytime highs moved from 10.7°C to 11.5°C and overnight lows from 8.8°C to 10.1°C over the same span.
December is one of the cooler months of the year in Penzance and a relatively wet time of year, so plan for around 11°C daytime highs and 9.3°C at night.
Not quite — December is the 5th coolest month in Penzance, averaging 10.2°C.
For December in Penzance, pack light layers you can adjust through the day, with typical highs of 11°C and lows of 9.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 83% — quite humid.
Average wind speed in December is 7.9 m/s. The windiest December on record averaged 9.9 m/s (2015).
The wettest December on record was 1999 with 221 mm. On average, December sees 120 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 Penzance behaves each December, 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 December specifically, along with year-by-year records and how the month has changed over the decades.
