December is one of the warmer months of the year in Thames, with average highs near 21°C and lows around 15°C (mean 18°C). It is about average for rainfall, averaging 91 mm of rainfall and 77% relative humidity across the period.
December is one of the warmer months of the year in Thames. Across 45 years of records, the warmest December in Thames was 2021 — when the month averaged 20°C — while the coldest was 2004 at 15.4°C. Typical December days reach 21°C with nights near 15°C. The long-term trend is warming, about 0.3°C per decade.
December is about average for rainfall in Thames, averaging 91 mm of rainfall. The wettest December on record was 1996 with 230 mm, while the driest was 1993 at 16 mm.
Relative humidity in Thames during December averages 77%. The most humid December was 2023 at 82%, and the least humid was 1993 at 72%.
December receives about 6.2 kWh/m²/day of solar energy in Thames. The sunniest December was 2017 at 7.3 kWh/m²/day, and the cloudiest was 2011 at 5.
Average wind speed in Thames during December is 2.8 m/s. The windiest December was 2004 at 3.9 m/s, while the calmest was 1981 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.9°C | 17.6°C | 17.6°C | 18.3°C | 19.0°C | +1.1°C |
| Avg High | 20.9°C | 20.8°C | 20.6°C | 21.3°C | 22.0°C | +1.1°C |
| Avg Low | 14.8°C | 14.5°C | 14.7°C | 15.2°C | 16.0°C | +1.2°C |
| Avg Rain | 115 mm | 74 mm | 88 mm | 88 mm | 94 mm | -20 mm |
December temperatures in Thames have risen by about 1.1°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 8.4°C (2006) to a record high of 26.2°C (1998).
Rainfall in December is about average for rainfall, averaging 91 mm, with a wettest year of 230 mm.
One of the best times to visit Thames
December is one of the best times to visit Thames. Expect days averaging 21°C and nights around 15°C (mean 18°C) — warmer than Thames's yearly average — with higher rainfall (91 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 | 21.9°C | 18.9°C | 16.0°C | 26.0°C | 13.8°C | 80 mm | 78% | 3 m/s | — |
| 2024 | 22.5°C | 19.1°C | 15.8°C | 25.1°C | 12.5°C | 90 mm | 79% | 2.7 m/s | 6.9 |
| 2023 | 21.4°C | 18.7°C | 16.0°C | 24.7°C | 12.8°C | 110 mm | 82% | 2.6 m/s | 5.7 |
| 2022 | 21.5°C | 18.9°C | 16.3°C | 24.8°C | 12.7°C | 163 mm | 81% | 2.4 m/s | 6.5 |
| 2021 🔥 | 22.8°C | 20.0°C | 17.2°C | 25.0°C | 14.6°C | 95 mm | 80% | 2.7 m/s | 6.2 |
| 2020 | 21.6°C | 18.1°C | 14.6°C | 24.6°C | 10.9°C | 28 mm | 74% | 2.8 m/s | 7 |
| 2019 | 22.3°C | 18.8°C | 15.2°C | 24.4°C | 11.5°C | 53 mm | 75% | 2.6 m/s | 6.9 |
| 2018 | 21.7°C | 18.8°C | 15.9°C | 25.2°C | 11.6°C | 204 mm | 80% | 2.5 m/s | 6.1 |
| 2017 | 22.4°C | 19.3°C | 16.1°C | 24.0°C | 12.9°C | 23 mm | 75% | 2.4 m/s | 7.3 |
| 2016 | 20.8°C | 17.4°C | 14.1°C | 22.6°C | 11.7°C | 35 mm | 76% | 2.8 m/s | 6.4 |
| 2015 | 20.9°C | 17.7°C | 14.4°C | 25.1°C | 11.8°C | 20 mm | 75% | 2.9 m/s | 6.8 |
| 2014 | 20.2°C | 17.4°C | 14.5°C | 23.2°C | 9.1°C | 97 mm | 79% | 2.8 m/s | 5.9 |
| 2013 | 21.5°C | 18.4°C | 15.3°C | 24.7°C | 12.0°C | 122 mm | 75% | 2.7 m/s | 6.4 |
| 2012 | 21.4°C | 18.4°C | 15.4°C | 24.1°C | 10.6°C | 60 mm | 80% | 2.6 m/s | 5.8 |
| 2011 | 19.6°C | 17.4°C | 15.2°C | 22.1°C | 12.5°C | 192 mm | 81% | 2.9 m/s | 5 |
| 2010 | 22.0°C | 19.1°C | 16.3°C | 25.9°C | 13.5°C | 78 mm | 80% | 2.5 m/s | 5.4 |
| 2009 | 21.2°C | 17.7°C | 14.2°C | 24.1°C | 11.4°C | 82 mm | 75% | 2.8 m/s | 6.4 |
| 2008 | 20.8°C | 17.8°C | 14.9°C | 23.8°C | 12.1°C | 91 mm | 78% | 2.9 m/s | 6 |
| 2007 | 20.9°C | 18.1°C | 15.3°C | 23.6°C | 13.1°C | 63 mm | 79% | 2.8 m/s | 5.8 |
| 2006 | 19.1°C | 15.8°C | 12.5°C | 22.0°C | 8.4°C | 62 mm | 74% | 3.1 m/s | 6.4 |
| 2005 | 21.5°C | 18.6°C | 15.8°C | 24.0°C | 12.8°C | 88 mm | 80% | 3 m/s | 5.8 |
| 2004 ❄️ | 18.2°C | 15.4°C | 12.6°C | 22.0°C | 8.5°C | 130 mm | 77% | 3.9 m/s | 5.6 |
| 2003 | 21.5°C | 18.3°C | 15.2°C | 24.0°C | 11.4°C | 90 mm | 78% | 2.4 m/s | 5.8 |
| 2002 | 20.5°C | 17.4°C | 14.4°C | 23.7°C | 12.0°C | 84 mm | 76% | 2.9 m/s | 6.1 |
| 2001 | 21.1°C | 18.7°C | 16.4°C | 23.8°C | 13.5°C | 146 mm | 82% | 3.1 m/s | 5.1 |
| 2000 | 21.2°C | 18.4°C | 15.6°C | 24.0°C | 13.2°C | 48 mm | 77% | 2.8 m/s | 5.9 |
| 1999 | 20.4°C | 17.3°C | 14.1°C | 23.4°C | 11.2°C | 43 mm | 74% | 2.9 m/s | 6.2 |
| 1998 | 21.5°C | 18.5°C | 15.4°C | 26.2°C | 12.6°C | 59 mm | 75% | 2.9 m/s | 6.2 |
| 1997 | 21.4°C | 17.9°C | 14.4°C | 24.1°C | 11.5°C | 46 mm | 76% | 2.4 m/s | 6.3 |
| 1996 🌧️ | 19.6°C | 16.8°C | 13.9°C | 22.9°C | 10.2°C | 230 mm | 78% | 3.1 m/s | 5.9 |
| 1995 | 21.3°C | 18.5°C | 15.6°C | 25.3°C | 13.7°C | 88 mm | 80% | 2.9 m/s | 6.1 |
| 1994 | 21.9°C | 18.3°C | 14.8°C | 24.3°C | 11.4°C | 23 mm | 73% | 2.7 m/s | 6.6 |
| 1993 | 20.4°C | 17.1°C | 13.8°C | 25.6°C | 10.9°C | 16 mm | 72% | 2.8 m/s | 5.9 |
| 1992 | 19.8°C | 17.0°C | 14.2°C | 21.7°C | 9.0°C | 169 mm | 79% | 2.9 m/s | 5.7 |
| 1991 | 19.9°C | 16.8°C | 13.7°C | 23.0°C | 10.4°C | 47 mm | 76% | 2.7 m/s | 6.4 |
| 1990 | 21.3°C | 18.1°C | 14.8°C | 25.1°C | 12.8°C | 23 mm | 75% | 3.3 m/s | 6.4 |
| 1989 | 20.5°C | 17.4°C | 14.4°C | 23.2°C | 11.6°C | 70 mm | 75% | 3.1 m/s | 6.5 |
| 1988 | 21.3°C | 18.4°C | 15.5°C | 23.9°C | 13.2°C | 208 mm | 77% | 2.8 m/s | 6.1 |
| 1987 | 20.4°C | 17.6°C | 14.8°C | 24.9°C | 12.0°C | 144 mm | 79% | 3 m/s | 6.1 |
| 1986 | 20.5°C | 17.3°C | 14.0°C | 22.8°C | 10.1°C | 116 mm | 74% | 2.5 m/s | 6.5 |
| 1985 | 21.0°C | 18.1°C | 15.2°C | 23.4°C | 12.1°C | 125 mm | 77% | 2.5 m/s | 6.4 |
| 1984 | 22.1°C | 19.0°C | 15.9°C | 25.0°C | 13.4°C | 149 mm | 81% | 2.4 m/s | 6.2 |
| 1983 | 19.9°C | 16.9°C | 13.9°C | 22.2°C | 10.8°C | 120 mm | 76% | 3.2 m/s | — |
| 1982 | 20.6°C | 17.2°C | 13.7°C | 23.8°C | 9.6°C | 38 mm | 73% | 3.1 m/s | — |
| 1981 | 21.9°C | 18.8°C | 15.8°C | 26.0°C | 12.9°C | 62 mm | 79% | 2.3 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 21°C with lows near 15°C (mean 18°C), based on 45 years of NASA POWER data.
December averages 91 mm of rainfall in Thames, about average for rainfall. The wettest on record was 230 mm in 1996.
The hottest December reached 26.2°C in 1998. The coldest dipped to 8.4°C in 2006.
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 21.1°C to 22°C and overnight lows from 14.9°C to 16.3°C over the same span.
December is one of the warmer months of the year in Thames and about average for rainfall, so plan for around 21°C daytime highs and 15°C at night.
Not quite — December is the 9th coolest month in Thames, averaging 18°C.
For December in Thames, pack light layers you can adjust through the day, with typical highs of 21°C and lows of 15°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 77% — quite humid.
Average wind speed in December is 2.8 m/s. The windiest December on record averaged 3.9 m/s (2004).
The wettest December on record was 1996 with 230 mm. On average, December sees 91 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 Thames 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.
