December is one of the cooler months of the year in Derry, with average highs near 7°C and lows around 3.7°C (mean 5.4°C). It is a relatively wet time of year, averaging 127 mm of rainfall and 92% relative humidity across the period.
December is one of the cooler months of the year in Derry. Across 45 years of records, the warmest December in Derry was 1988 — when the month averaged 7.4°C — while the coldest was 2010 at 1.8°C. Typical December days reach 7°C with nights near 3.7°C. The long-term trend is warming, about 0.3°C per decade.
December is a relatively wet time of year in Derry, averaging 127 mm of rainfall. The wettest December on record was 1999 with 217 mm, while the driest was 1995 at 57 mm.
Relative humidity in Derry during December averages 92%. The most humid December was 2018 at 94%, and the least humid was 2011 at 90%.
December receives about 0.4 kWh/m²/day of solar energy in Derry. The sunniest Decembers were 2019, 2020 and 2022, among others at 0.5 kWh/m²/day, and the cloudiest were 2021, 2023 and 2024, among others at 0.4.
Average wind speed in Derry during December is 5.2 m/s. The windiest December was 2013 at 6.8 m/s, while the calmest was 2010 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 5.1°C | 4.9°C | 5.4°C | 5.5°C | 6.0°C | +0.9°C |
| Avg High | 6.7°C | 6.6°C | 7.0°C | 7.2°C | 7.5°C | +0.8°C |
| Avg Low | 3.5°C | 3.3°C | 3.8°C | 3.8°C | 4.5°C | +1°C |
| Avg Rain | 118 mm | 133 mm | 118 mm | 134 mm | 134 mm | +16 mm |
December temperatures in Derry have risen by about 1.4°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -4.7°C (1981) to a record high of 13.5°C (2025).
Rainfall in December is a relatively wet time of year, averaging 127 mm, with a wettest year of 217 mm.
A quieter season to visit Derry
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Derry. That said, December — with days averaging 7°C and nights around 3.7°C (mean 5.4°C) and higher rainfall (127 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 | 7.8°C | 6.2°C | 4.7°C | 13.5°C | 0.7°C | 104 mm | 94% | 4.8 m/s | — |
| 2024 | 8.7°C | 7.0°C | 5.2°C | 11.9°C | 0.4°C | 119 mm | 91% | 5.5 m/s | 0.4 |
| 2023 | 8.1°C | 6.7°C | 5.4°C | 11.5°C | 1.1°C | 181 mm | 92% | 5.6 m/s | 0.4 |
| 2022 | 6.0°C | 4.3°C | 2.7°C | 12.0°C | -0.4°C | 118 mm | 92% | 4.4 m/s | 0.5 |
| 2021 | 7.9°C | 6.4°C | 4.9°C | 11.4°C | 2.1°C | 142 mm | 93% | 4.8 m/s | 0.4 |
| 2020 | 6.7°C | 5.4°C | 4.0°C | 10.1°C | 1.0°C | 139 mm | 91% | 5.1 m/s | 0.5 |
| 2019 | 7.4°C | 5.7°C | 4.1°C | 12.1°C | 0.2°C | 127 mm | 92% | 5.3 m/s | 0.5 |
| 2018 | 8.2°C | 6.6°C | 5.1°C | 11.1°C | 2.3°C | 124 mm | 94% | 5 m/s | 0.4 |
| 2017 | 7.2°C | 5.5°C | 3.8°C | 11.9°C | -0.5°C | 122 mm | 92% | 4.7 m/s | 0.4 |
| 2016 | 8.1°C | 6.3°C | 4.6°C | 13.3°C | 1.4°C | 78 mm | 93% | 5.3 m/s | 0.5 |
| 2015 | 9.3°C | 7.1°C | 4.8°C | 13.0°C | 1.7°C | 201 mm | 92% | 6.4 m/s | 0.4 |
| 2014 | 6.8°C | 5.3°C | 3.8°C | 11.2°C | -0.1°C | 151 mm | 90% | 5.5 m/s | 0.5 |
| 2013 | 8.0°C | 6.2°C | 4.3°C | 12.7°C | 1.3°C | 123 mm | 91% | 6.8 m/s | 0.4 |
| 2012 | 6.6°C | 4.8°C | 3.1°C | 11.4°C | 0.4°C | 157 mm | 92% | 4.9 m/s | 0.5 |
| 2011 | 7.3°C | 5.8°C | 4.3°C | 11.3°C | 1.4°C | 193 mm | 90% | 6.7 m/s | 0.4 |
| 2010 ❄️ | 3.4°C | 1.8°C | 0.3°C | 8.3°C | -3.3°C | 62 mm | 90% | 3.1 m/s | 0.5 |
| 2009 | 5.2°C | 3.8°C | 2.3°C | 9.3°C | -1.0°C | 87 mm | 91% | 4.2 m/s | 0.5 |
| 2008 | 6.5°C | 4.7°C | 2.9°C | 10.8°C | -0.1°C | 98 mm | 91% | 4.4 m/s | 0.5 |
| 2007 | 7.8°C | 6.0°C | 4.1°C | 12.5°C | 0.7°C | 139 mm | 92% | 5.7 m/s | 0.4 |
| 2006 | 8.0°C | 6.4°C | 4.9°C | 11.7°C | 1.2°C | 165 mm | 92% | 6 m/s | 0.4 |
| 2005 | 7.7°C | 6.0°C | 4.3°C | 11.0°C | 0.1°C | 109 mm | 93% | 4.4 m/s | 0.4 |
| 2004 | 8.1°C | 6.4°C | 4.8°C | 11.3°C | -0.6°C | 132 mm | 91% | 5.9 m/s | 0.4 |
| 2003 | 7.5°C | 5.6°C | 3.8°C | 11.0°C | 0.1°C | 119 mm | 92% | 4.6 m/s | 0.4 |
| 2002 | 6.4°C | 5.2°C | 4.0°C | 11.2°C | 0.7°C | 92 mm | 92% | 4.4 m/s | 0.4 |
| 2001 | 6.6°C | 4.8°C | 3.0°C | 10.1°C | -0.8°C | 90 mm | 91% | 4.6 m/s | 0.5 |
| 2000 | 6.3°C | 5.0°C | 3.7°C | 10.8°C | -1.6°C | 151 mm | 93% | 5 m/s | 0.4 |
| 1999 🌧️ | 6.7°C | 5.0°C | 3.3°C | 11.1°C | 0.1°C | 217 mm | 90% | 5.9 m/s | 0.4 |
| 1998 | 8.1°C | 6.1°C | 4.1°C | 12.3°C | -0.3°C | 110 mm | 92% | 5.8 m/s | 0.4 |
| 1997 | 7.7°C | 6.3°C | 4.9°C | 11.4°C | 1.5°C | 150 mm | 93% | 5.4 m/s | 0.4 |
| 1996 | 5.3°C | 3.9°C | 2.4°C | 10.4°C | -0.5°C | 65 mm | 92% | 4.3 m/s | 0.5 |
| 1995 | 4.7°C | 3.0°C | 1.3°C | 11.6°C | -3.3°C | 57 mm | 91% | 4.1 m/s | 0.4 |
| 1994 | 7.8°C | 6.1°C | 4.4°C | 12.7°C | 0.5°C | 168 mm | 91% | 6.3 m/s | 0.4 |
| 1993 | 6.3°C | 4.6°C | 2.8°C | 10.9°C | -0.7°C | 215 mm | 90% | 5.9 m/s | 0.4 |
| 1992 | 5.8°C | 4.2°C | 2.7°C | 9.4°C | -0.9°C | 112 mm | 93% | 4.8 m/s | 0.5 |
| 1991 | 7.4°C | 5.8°C | 4.2°C | 11.3°C | 1.1°C | 98 mm | 93% | 5.2 m/s | 0.5 |
| 1990 | 6.1°C | 4.2°C | 2.4°C | 11.3°C | -0.2°C | 136 mm | 90% | 5.3 m/s | 0.4 |
| 1989 | 5.5°C | 4.0°C | 2.5°C | 10.1°C | 0.1°C | 78 mm | 92% | 4.3 m/s | 0.5 |
| 1988 🔥 | 8.9°C | 7.4°C | 5.8°C | 11.4°C | 0.8°C | 91 mm | 92% | 5.9 m/s | 0.4 |
| 1987 | 7.2°C | 5.7°C | 4.2°C | 11.7°C | -0.5°C | 76 mm | 93% | 5 m/s | 0.4 |
| 1986 | 7.2°C | 5.2°C | 3.3°C | 11.4°C | 0.9°C | 187 mm | 90% | 6 m/s | 0.4 |
| 1985 | 7.3°C | 5.8°C | 4.3°C | 12.8°C | -1.6°C | 123 mm | 92% | 5.2 m/s | 0.4 |
| 1984 | 6.9°C | 5.2°C | 3.6°C | 10.9°C | -0.2°C | 136 mm | 92% | 4.9 m/s | 0.4 |
| 1983 | 7.8°C | 6.2°C | 4.6°C | 11.1°C | 1.3°C | 145 mm | 92% | 5.7 m/s | — |
| 1982 | 6.2°C | 4.3°C | 2.4°C | 10.7°C | -0.2°C | 159 mm | 91% | 5.6 m/s | — |
| 1981 | 3.7°C | 2.1°C | 0.5°C | 10.4°C | -4.7°C | 69 mm | 91% | 4.1 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 7°C with lows near 3.7°C (mean 5.4°C), based on 45 years of NASA POWER data.
December averages 127 mm of rainfall in Derry, a relatively wet time of year. The wettest on record was 217 mm in 1999.
The hottest December reached 13.5°C in 2025. The coldest dipped to -4.7°C in 1981.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.4°C. Daytime highs moved from 6.4°C to 7.7°C and overnight lows from 3.1°C to 4.6°C over the same span.
December is one of the cooler months of the year in Derry and a relatively wet time of year, so plan for around 7°C daytime highs and 3.7°C at night.
Not quite — December is the 3rd coolest month in Derry, averaging 5.4°C.
For December in Derry, pack warm layers and a jacket for chilly mornings, with typical highs of 7°C and lows of 3.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 92% — quite humid.
Average wind speed in December is 5.2 m/s. The windiest December on record averaged 6.8 m/s (2013).
The wettest December on record was 1999 with 217 mm. On average, December sees 127 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 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.
