December is one of the cooler months of the year in Greenock, with average highs near 5.8°C and lows around 2.7°C (mean 4.3°C). It is a relatively wet time of year, averaging 158 mm of rainfall and 93% relative humidity across the period.
December is one of the cooler months of the year in Greenock. Across 45 years of records, the warmest December in Greenock was 1988 — when the month averaged 6.5°C — while the coldest was 1981 at 0.1°C. Typical December days reach 5.8°C with nights near 2.7°C. The long-term trend is warming, about 0.3°C per decade.
December is a relatively wet time of year in Greenock, averaging 158 mm of rainfall. The wettest December on record was 2015 with 312 mm, while the driest was 1995 at 45 mm.
Relative humidity in Greenock during December averages 93%. The most humid December was 1997 at 95%, and the least humid was 2014 at 91%.
December receives about 0.4 kWh/m²/day of solar energy in Greenock. The sunniest December was 2010 at 0.5 kWh/m²/day, and the cloudiest were 2019, 2021 and 2023, among others at 0.3.
Average wind speed in Greenock during December is 4.7 m/s. The windiest December was 2013 at 6.8 m/s, while the calmest was 2010 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 3.9°C | 3.8°C | 4.4°C | 4.6°C | 4.8°C | +0.9°C |
| Avg High | 5.5°C | 5.3°C | 5.9°C | 6.2°C | 6.3°C | +0.8°C |
| Avg Low | 2.4°C | 2.3°C | 2.8°C | 3.0°C | 3.3°C | +0.9°C |
| Avg Rain | 156 mm | 161 mm | 137 mm | 178 mm | 154 mm | -2 mm |
December temperatures in Greenock have risen by about 1.3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -7.3°C (1995) to a record high of 12.3°C (2025).
Rainfall in December is a relatively wet time of year, averaging 158 mm, with a wettest year of 312 mm.
A quieter season to visit Greenock
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Greenock. That said, December — with days averaging 5.8°C and nights around 2.7°C (mean 4.3°C) and higher rainfall (158 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 | 7.0°C | 5.6°C | 4.2°C | 12.3°C | -0.1°C | 151 mm | 94% | 4.4 m/s | — |
| 2024 | 7.7°C | 6.0°C | 4.4°C | 11.6°C | -0.4°C | 172 mm | 93% | 5.2 m/s | 0.4 |
| 2023 | 6.4°C | 5.0°C | 3.6°C | 10.8°C | -1.5°C | 181 mm | 94% | 5.3 m/s | 0.3 |
| 2022 | 4.8°C | 3.2°C | 1.7°C | 11.3°C | -3.2°C | 127 mm | 93% | 4 m/s | 0.4 |
| 2021 | 6.0°C | 4.6°C | 3.1°C | 10.4°C | 0.3°C | 142 mm | 94% | 4 m/s | 0.3 |
| 2020 | 5.9°C | 4.4°C | 2.9°C | 10.5°C | -0.4°C | 153 mm | 94% | 4.4 m/s | 0.4 |
| 2019 | 6.7°C | 5.4°C | 4.0°C | 11.0°C | 0.2°C | 186 mm | 93% | 4.9 m/s | 0.3 |
| 2018 | 6.6°C | 5.2°C | 3.9°C | 10.1°C | 0.2°C | 149 mm | 94% | 4.4 m/s | 0.4 |
| 2017 | 5.8°C | 4.2°C | 2.6°C | 10.7°C | -1.7°C | 134 mm | 94% | 4 m/s | 0.4 |
| 2016 | 7.6°C | 6.1°C | 4.5°C | 11.9°C | 0.0°C | 123 mm | 94% | 5 m/s | 0.3 |
| 2015 🌧️ | 8.2°C | 6.3°C | 4.4°C | 11.6°C | 0.7°C | 312 mm | 92% | 6.4 m/s | 0.3 |
| 2014 | 6.0°C | 4.6°C | 3.1°C | 10.1°C | 0.0°C | 163 mm | 91% | 5.1 m/s | 0.4 |
| 2013 | 7.5°C | 5.8°C | 4.2°C | 10.8°C | -0.6°C | 226 mm | 92% | 6.8 m/s | 0.3 |
| 2012 | 4.9°C | 3.2°C | 1.5°C | 10.0°C | -1.6°C | 205 mm | 94% | 4.7 m/s | 0.4 |
| 2011 | 6.3°C | 4.7°C | 3.1°C | 10.3°C | -0.3°C | 235 mm | 91% | 6 m/s | 0.3 |
| 2010 | 1.9°C | 0.2°C | -1.6°C | 7.1°C | -5.1°C | 50 mm | 94% | 2.9 m/s | 0.5 |
| 2009 | 3.6°C | 2.0°C | 0.4°C | 8.7°C | -4.1°C | 82 mm | 93% | 3.3 m/s | 0.4 |
| 2008 | 5.2°C | 3.5°C | 1.9°C | 9.9°C | -1.1°C | 113 mm | 93% | 3.8 m/s | 0.4 |
| 2007 | 6.5°C | 4.9°C | 3.3°C | 11.2°C | -0.4°C | 126 mm | 93% | 4.8 m/s | 0.4 |
| 2006 | 7.5°C | 5.9°C | 4.2°C | 11.3°C | 1.5°C | 257 mm | 93% | 5.5 m/s | 0.4 |
| 2005 | 6.3°C | 4.8°C | 3.3°C | 10.1°C | -0.8°C | 112 mm | 94% | 4 m/s | 0.4 |
| 2004 | 7.3°C | 5.7°C | 4.2°C | 10.3°C | -1.5°C | 161 mm | 93% | 5.3 m/s | 0.4 |
| 2003 | 6.3°C | 4.6°C | 2.8°C | 10.0°C | -1.8°C | 148 mm | 93% | 4.3 m/s | 0.4 |
| 2002 | 5.3°C | 4.0°C | 2.7°C | 9.6°C | -0.2°C | 80 mm | 94% | 3.8 m/s | 0.4 |
| 2001 | 5.5°C | 3.7°C | 1.8°C | 10.6°C | -1.9°C | 83 mm | 92% | 4 m/s | 0.4 |
| 2000 | 5.5°C | 4.4°C | 3.3°C | 10.6°C | -3.3°C | 213 mm | 94% | 4.8 m/s | 0.3 |
| 1999 | 4.9°C | 3.3°C | 1.7°C | 10.3°C | -3.4°C | 264 mm | 92% | 5.2 m/s | 0.3 |
| 1998 | 7.0°C | 5.2°C | 3.5°C | 11.0°C | -1.1°C | 154 mm | 93% | 5.2 m/s | 0.3 |
| 1997 | 6.5°C | 5.1°C | 3.6°C | 10.6°C | -0.7°C | 164 mm | 95% | 4.8 m/s | 0.3 |
| 1996 | 3.8°C | 2.5°C | 1.2°C | 8.3°C | -2.5°C | 87 mm | 94% | 3.9 m/s | 0.4 |
| 1995 | 2.7°C | 1.2°C | -0.3°C | 11.0°C | -7.3°C | 45 mm | 94% | 3.8 m/s | 0.3 |
| 1994 | 6.6°C | 5.1°C | 3.6°C | 11.8°C | -0.6°C | 242 mm | 92% | 5.7 m/s | 0.3 |
| 1993 | 4.7°C | 3.1°C | 1.6°C | 9.6°C | -3.5°C | 224 mm | 92% | 5.2 m/s | 0.3 |
| 1992 | 4.9°C | 3.6°C | 2.3°C | 8.7°C | -0.8°C | 145 mm | 94% | 4.3 m/s | 0.4 |
| 1991 | 6.8°C | 5.2°C | 3.6°C | 10.2°C | 0.6°C | 138 mm | 93% | 4.6 m/s | 0.4 |
| 1990 | 5.2°C | 3.6°C | 2.0°C | 9.8°C | -1.5°C | 153 mm | 91% | 5 m/s | 0.3 |
| 1989 | 4.0°C | 2.6°C | 1.2°C | 9.8°C | -2.8°C | 87 mm | 94% | 3.7 m/s | 0.4 |
| 1988 🔥 | 8.0°C | 6.5°C | 5.1°C | 10.5°C | 0.3°C | 112 mm | 93% | 5.7 m/s | 0.3 |
| 1987 | 6.0°C | 4.4°C | 2.9°C | 10.5°C | -1.6°C | 131 mm | 94% | 4.4 m/s | 0.3 |
| 1986 | 5.9°C | 4.2°C | 2.4°C | 10.2°C | -1.2°C | 263 mm | 92% | 5.5 m/s | 0.3 |
| 1985 | 6.2°C | 4.7°C | 3.2°C | 11.4°C | -5.1°C | 205 mm | 93% | 4.9 m/s | 0.3 |
| 1984 | 6.2°C | 4.7°C | 3.1°C | 9.9°C | -0.8°C | 159 mm | 93% | 4.6 m/s | 0.3 |
| 1983 | 6.7°C | 5.0°C | 3.4°C | 10.4°C | -0.5°C | 199 mm | 93% | 5.5 m/s | — |
| 1982 | 4.9°C | 3.3°C | 1.7°C | 8.9°C | -1.7°C | 184 mm | 92% | 4.9 m/s | — |
| 1981 ❄️ | 1.6°C | 0.1°C | -1.4°C | 9.4°C | -6.6°C | 67 mm | 92% | 3.8 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 5.8°C with lows near 2.7°C (mean 4.3°C), based on 45 years of NASA POWER data.
December averages 158 mm of rainfall in Greenock, a relatively wet time of year. The wettest on record was 312 mm in 2015.
The hottest December reached 12.3°C in 2025. The coldest dipped to -7.3°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.3°C. Daytime highs moved from 5.1°C to 6.4°C and overnight lows from 2°C to 3.4°C over the same span.
December is one of the cooler months of the year in Greenock and a relatively wet time of year, so plan for around 5.8°C daytime highs and 2.7°C at night.
Not quite — December is the 3rd coolest month in Greenock, averaging 4.3°C.
For December in Greenock, pack warm layers and a jacket for chilly mornings, with typical highs of 5.8°C and lows of 2.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 93% — quite humid.
Average wind speed in December is 4.7 m/s. The windiest December on record averaged 6.8 m/s (2013).
The wettest December on record was 2015 with 312 mm. On average, December sees 158 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 Greenock 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.
