January is one of the cooler months of the year in Swansea, with average highs near 7.5°C and lows around 4.1°C (mean 5.8°C). It is a relatively wet time of year, averaging 110 mm of rainfall and 91% relative humidity across the period.
January is one of the cooler months of the year in Swansea. Across 45 years of records, the warmest January in Swansea was 2007 — when the month averaged 7.9°C — while the coldest was 1987 at 2°C. Typical January days reach 7.5°C with nights near 4.1°C. The long-term trend is warming, about 0.2°C per decade.
January is a relatively wet time of year in Swansea, averaging 110 mm of rainfall. The wettest January on record was 2016 with 181 mm, while the driest was 1997 at 16 mm.
Relative humidity in Swansea during January averages 91%. The most humid January was 1982 at 94%, and the least humid was 1984 at 87%.
January receives about 0.8 kWh/m²/day of solar energy in Swansea. The sunniest January was 1985 at 1.1 kWh/m²/day, and the cloudiest were 2013, 2014 and 2020, among others at 0.7.
Average wind speed in Swansea during January is 5.3 m/s. The windiest Januarys were 1984 and 2007 at 6.7 m/s, while the calmest was 2022 at 3.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 5.1°C | 5.8°C | 6.3°C | 5.7°C | 6.1°C | +1°C |
| Avg High | 6.8°C | 7.5°C | 7.9°C | 7.4°C | 7.8°C | +1°C |
| Avg Low | 3.4°C | 4.1°C | 4.7°C | 4.1°C | 4.4°C | +1°C |
| Avg Rain | 106 mm | 115 mm | 101 mm | 116 mm | 116 mm | +10 mm |
January temperatures in Swansea have risen by about 0.8°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -6.6°C (1987) to a record high of 12.3°C (2016).
Rainfall in January is a relatively wet time of year, averaging 110 mm, with a wettest year of 181 mm.
A quieter season to visit Swansea
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Swansea. That said, January — with days averaging 7.5°C and nights around 4.1°C (mean 5.8°C) and higher rainfall (110 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 | 7.3°C | 5.4°C | 3.5°C | 11.5°C | 0.0°C | 125 mm | 91% | 4.4 m/s | 0.9 |
| 2024 | 7.6°C | 5.9°C | 4.2°C | 11.7°C | -0.2°C | 96 mm | 89% | 5.1 m/s | 0.9 |
| 2023 | 8.2°C | 6.5°C | 4.8°C | 11.8°C | 0.8°C | 128 mm | 89% | 5.1 m/s | 0.9 |
| 2022 | 8.1°C | 6.2°C | 4.4°C | 12.1°C | 1.9°C | 56 mm | 90% | 3.8 m/s | 0.8 |
| 2021 | 6.6°C | 5.0°C | 3.5°C | 10.7°C | 0.6°C | 171 mm | 91% | 5 m/s | 0.8 |
| 2020 | 8.8°C | 7.3°C | 5.7°C | 12.2°C | 1.9°C | 120 mm | 91% | 4.8 m/s | 0.7 |
| 2019 | 7.1°C | 5.6°C | 4.1°C | 9.9°C | 0.9°C | 67 mm | 90% | 4.1 m/s | 0.8 |
| 2018 | 8.5°C | 6.6°C | 4.7°C | 11.9°C | 0.8°C | 146 mm | 91% | 6.1 m/s | 0.8 |
| 2017 | 7.5°C | 5.8°C | 4.0°C | 10.5°C | -0.2°C | 88 mm | 92% | 4.3 m/s | 0.8 |
| 2016 🌧️ | 8.6°C | 7.0°C | 5.5°C | 12.3°C | 0.6°C | 181 mm | 90% | 5.8 m/s | 0.8 |
| 2015 | 8.3°C | 6.3°C | 4.3°C | 11.8°C | 0.8°C | 152 mm | 88% | 5.9 m/s | 0.9 |
| 2014 | 8.6°C | 6.9°C | 5.2°C | 10.9°C | 2.1°C | 144 mm | 91% | 5.5 m/s | 0.7 |
| 2013 | 6.7°C | 5.3°C | 3.9°C | 11.0°C | -0.8°C | 120 mm | 92% | 5 m/s | 0.7 |
| 2012 | 8.3°C | 6.6°C | 5.0°C | 11.1°C | 0.1°C | 94 mm | 91% | 5.5 m/s | 0.8 |
| 2011 | 6.2°C | 4.4°C | 2.6°C | 10.2°C | -1.3°C | 105 mm | 91% | 4.3 m/s | 0.8 |
| 2010 | 4.5°C | 2.9°C | 1.3°C | 8.9°C | -2.4°C | 68 mm | 92% | 4.4 m/s | 0.8 |
| 2009 | 6.2°C | 4.6°C | 3.1°C | 9.9°C | -2.4°C | 133 mm | 91% | 4.9 m/s | 0.9 |
| 2008 | 9.1°C | 7.5°C | 6.0°C | 11.2°C | 0.7°C | 144 mm | 90% | 6.4 m/s | 0.7 |
| 2007 🔥 | 9.4°C | 7.9°C | 6.5°C | 12.0°C | 0.8°C | 122 mm | 88% | 6.7 m/s | 0.8 |
| 2006 | 7.0°C | 5.3°C | 3.5°C | 10.3°C | -0.2°C | 41 mm | 92% | 4.7 m/s | 0.8 |
| 2005 | 8.9°C | 7.2°C | 5.5°C | 12.1°C | 1.3°C | 71 mm | 89% | 6.4 m/s | 0.8 |
| 2004 | 8.4°C | 6.9°C | 5.4°C | 11.3°C | 0.0°C | 141 mm | 89% | 5.6 m/s | 0.8 |
| 2003 | 7.1°C | 5.6°C | 4.2°C | 11.7°C | -0.6°C | 99 mm | 90% | 5.7 m/s | 0.9 |
| 2002 | 8.7°C | 7.0°C | 5.4°C | 11.5°C | 0.6°C | 114 mm | 93% | 5.4 m/s | 0.7 |
| 2001 | 6.4°C | 5.0°C | 3.5°C | 11.2°C | 0.0°C | 93 mm | 92% | 5 m/s | 0.9 |
| 2000 | 7.5°C | 5.8°C | 4.1°C | 10.9°C | 0.9°C | 51 mm | 91% | 4.7 m/s | 0.9 |
| 1999 | 8.7°C | 7.1°C | 5.4°C | 11.6°C | 0.5°C | 149 mm | 91% | 5.6 m/s | 0.8 |
| 1998 | 8.0°C | 6.3°C | 4.5°C | 12.2°C | 0.0°C | 139 mm | 90% | 6.1 m/s | 0.8 |
| 1997 | 4.6°C | 2.9°C | 1.2°C | 8.7°C | -3.0°C | 16 mm | 93% | 4.3 m/s | 0.8 |
| 1996 | 6.8°C | 5.4°C | 4.0°C | 10.4°C | -2.6°C | 89 mm | 93% | 6.2 m/s | 0.8 |
| 1995 | 8.4°C | 6.4°C | 4.4°C | 11.2°C | -0.1°C | 174 mm | 90% | 6.3 m/s | 0.7 |
| 1994 | 7.8°C | 6.2°C | 4.6°C | 10.6°C | 1.1°C | 140 mm | 91% | 5.8 m/s | 0.8 |
| 1993 | 8.9°C | 6.9°C | 5.0°C | 11.7°C | 0.1°C | 130 mm | 91% | 6.1 m/s | 0.7 |
| 1992 | 6.4°C | 4.7°C | 2.9°C | 10.8°C | -1.4°C | 43 mm | 92% | 4.2 m/s | 0.9 |
| 1991 | 6.1°C | 4.5°C | 2.8°C | 11.3°C | -1.0°C | 118 mm | 89% | 5.2 m/s | 0.9 |
| 1990 | 9.3°C | 7.6°C | 6.0°C | 11.4°C | 2.6°C | 147 mm | 91% | 6.1 m/s | 0.8 |
| 1989 | 9.0°C | 7.2°C | 5.4°C | 11.8°C | 2.4°C | 60 mm | 90% | 4.6 m/s | 0.9 |
| 1988 | 8.0°C | 6.4°C | 4.8°C | 11.9°C | 2.3°C | 170 mm | 91% | 5.7 m/s | 0.7 |
| 1987 ❄️ | 3.8°C | 2.0°C | 0.3°C | 10.7°C | -6.6°C | 35 mm | 90% | 4.8 m/s | 0.9 |
| 1986 | 6.8°C | 5.3°C | 3.7°C | 10.9°C | 0.4°C | 119 mm | 88% | 6.1 m/s | 0.7 |
| 1985 | 3.9°C | 2.2°C | 0.5°C | 10.0°C | -4.3°C | 86 mm | 91% | 4.6 m/s | 1.1 |
| 1984 | 7.2°C | 5.3°C | 3.4°C | 11.6°C | -1.2°C | 170 mm | 87% | 6.7 m/s | 0.7 |
| 1983 | 8.8°C | 7.2°C | 5.6°C | 11.4°C | 1.7°C | 127 mm | 90% | 6.6 m/s | — |
| 1982 | 5.9°C | 4.3°C | 2.8°C | 10.6°C | -4.5°C | 128 mm | 94% | 5.4 m/s | — |
| 1981 | 7.7°C | 6.0°C | 4.3°C | 10.1°C | 0.7°C | 57 mm | 90% | 5.1 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 7.5°C with lows near 4.1°C (mean 5.8°C), based on 45 years of NASA POWER data.
January averages 110 mm of rainfall in Swansea, a relatively wet time of year. The wettest on record was 181 mm in 2016.
The hottest January reached 12.3°C in 2016. The coldest dipped to -6.6°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.8°C. Daytime highs moved from 6.7°C to 7.6°C and overnight lows from 3.3°C to 4.1°C over the same span.
January is one of the cooler months of the year in Swansea and a relatively wet time of year, so plan for around 7.5°C daytime highs and 4.1°C at night.
Not quite — January is the 2nd coolest month in Swansea, averaging 5.8°C.
For January in Swansea, pack warm layers and a jacket for chilly mornings, with typical highs of 7.5°C and lows of 4.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 91% — quite humid.
Average wind speed in January is 5.3 m/s. The windiest January on record averaged 6.7 m/s (1984).
The wettest January on record was 2016 with 181 mm. On average, January sees 110 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 Swansea 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.
