January is one of the cooler months of the year in Welwyn Garden City, with average highs near 6.4°C and lows around 1°C (mean 3.7°C). It is about average for rainfall, averaging 60 mm of rainfall and 93% relative humidity across the period.
January is one of the cooler months of the year in Welwyn Garden City. Across 45 years of records, the warmest January in Welwyn Garden City was 2007 — when the month averaged 6.3°C — while the coldest was 1987 at -0.6°C. Typical January days reach 6.4°C with nights near 1°C. The long-term trend is warming, about 0.2°C per decade.
January is about average for rainfall in Welwyn Garden City, averaging 60 mm of rainfall. The wettest January on record was 1988 with 116 mm, while the driest was 1997 at 16 mm.
Relative humidity in Welwyn Garden City during January averages 93%. The most humid January was 2001 at 95%, and the least humid was 1991 at 90%.
January receives about 0.8 kWh/m²/day of solar energy in Welwyn Garden City. The sunniest January was 1985 at 1.1 kWh/m²/day, and the cloudiest were 1993, 2002 and 2013, among others at 0.7.
Average wind speed in Welwyn Garden City during January is 3.9 m/s. The windiest January was 1983 at 5.2 m/s, while the calmest was 1997 at 2.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 2.8°C | 4.0°C | 4.3°C | 3.6°C | 4.1°C | +1.3°C |
| Avg High | 5.4°C | 6.6°C | 6.9°C | 6.3°C | 6.9°C | +1.5°C |
| Avg Low | 0.1°C | 1.3°C | 1.6°C | 0.9°C | 1.2°C | +1.1°C |
| Avg Rain | 63 mm | 61 mm | 57 mm | 58 mm | 63 mm | 0 mm |
January temperatures in Welwyn Garden City have risen by about 1°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -8.7°C (1987) to a record high of 13.4°C (2016).
Rainfall in January is about average for rainfall, averaging 60 mm, with a wettest year of 116 mm.
A quieter season to visit Welwyn Garden City
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Welwyn Garden City. That said, January — with days averaging 6.4°C and nights around 1°C (mean 3.7°C) and moderate rainfall (60 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 | 6.0°C | 3.2°C | 0.4°C | 11.1°C | -3.9°C | 63 mm | 95% | 3.1 m/s | 0.9 |
| 2024 | 7.1°C | 4.0°C | 0.8°C | 12.6°C | -4.7°C | 58 mm | 92% | 4 m/s | 1 |
| 2023 | 7.4°C | 4.3°C | 1.3°C | 12.5°C | -4.8°C | 67 mm | 94% | 4 m/s | 0.9 |
| 2022 | 7.2°C | 4.3°C | 1.3°C | 12.8°C | -2.8°C | 22 mm | 94% | 3.1 m/s | 0.9 |
| 2021 | 5.3°C | 2.7°C | 0.2°C | 11.7°C | -3.7°C | 113 mm | 95% | 3.5 m/s | 0.8 |
| 2020 | 8.6°C | 6.0°C | 3.4°C | 12.7°C | -1.7°C | 54 mm | 94% | 3.9 m/s | 0.8 |
| 2019 | 5.7°C | 2.9°C | 0.0°C | 10.6°C | -4.0°C | 29 mm | 93% | 3.3 m/s | 0.9 |
| 2018 | 7.8°C | 5.0°C | 2.1°C | 13.0°C | -1.7°C | 62 mm | 93% | 4.2 m/s | 0.8 |
| 2017 | 5.5°C | 2.7°C | -0.1°C | 9.1°C | -3.4°C | 63 mm | 94% | 2.8 m/s | 0.9 |
| 2016 | 7.7°C | 5.0°C | 2.4°C | 13.4°C | -3.5°C | 74 mm | 92% | 4.3 m/s | 0.8 |
| 2015 | 6.8°C | 3.6°C | 0.4°C | 13.1°C | -4.0°C | 71 mm | 92% | 4.3 m/s | 0.9 |
| 2014 | 8.1°C | 5.6°C | 3.0°C | 11.6°C | -0.6°C | 80 mm | 94% | 4.3 m/s | 0.8 |
| 2013 | 4.9°C | 2.7°C | 0.4°C | 12.7°C | -5.2°C | 48 mm | 94% | 3.2 m/s | 0.7 |
| 2012 | 7.7°C | 4.8°C | 1.9°C | 11.6°C | -3.6°C | 43 mm | 92% | 3.8 m/s | 0.9 |
| 2011 | 5.6°C | 3.0°C | 0.4°C | 12.7°C | -4.0°C | 66 mm | 95% | 3.4 m/s | 0.8 |
| 2010 | 2.9°C | 0.6°C | -1.8°C | 7.3°C | -5.3°C | 47 mm | 95% | 2.8 m/s | 0.8 |
| 2009 | 4.8°C | 2.2°C | -0.4°C | 9.5°C | -7.5°C | 55 mm | 94% | 3.4 m/s | 0.9 |
| 2008 | 8.9°C | 6.2°C | 3.6°C | 12.7°C | -1.1°C | 73 mm | 92% | 4.8 m/s | 0.8 |
| 2007 🔥 | 9.1°C | 6.3°C | 3.4°C | 13.0°C | -2.9°C | 62 mm | 91% | 5.1 m/s | 0.9 |
| 2006 | 6.1°C | 3.4°C | 0.6°C | 10.8°C | -3.8°C | 26 mm | 94% | 3.1 m/s | 0.8 |
| 2005 | 8.1°C | 5.4°C | 2.6°C | 12.1°C | -2.3°C | 25 mm | 91% | 4.8 m/s | 0.8 |
| 2004 | 6.7°C | 4.2°C | 1.8°C | 12.0°C | -4.0°C | 94 mm | 94% | 4.2 m/s | 0.8 |
| 2003 | 6.2°C | 3.7°C | 1.3°C | 13.0°C | -3.8°C | 80 mm | 94% | 4.2 m/s | 0.9 |
| 2002 | 7.4°C | 4.8°C | 2.2°C | 12.1°C | -6.2°C | 52 mm | 95% | 4 m/s | 0.7 |
| 2001 | 5.3°C | 2.8°C | 0.2°C | 10.4°C | -4.3°C | 78 mm | 95% | 3.3 m/s | 0.9 |
| 2000 | 6.8°C | 4.0°C | 1.1°C | 12.2°C | -2.5°C | 29 mm | 95% | 3.9 m/s | 1 |
| 1999 | 7.8°C | 5.2°C | 2.6°C | 12.4°C | -3.6°C | 77 mm | 94% | 4.4 m/s | 0.8 |
| 1998 | 7.5°C | 4.6°C | 1.7°C | 13.3°C | -3.6°C | 76 mm | 92% | 4.3 m/s | 0.8 |
| 1997 | 3.3°C | 0.7°C | -1.9°C | 8.2°C | -8.2°C | 16 mm | 95% | 2.5 m/s | 0.8 |
| 1996 | 5.2°C | 3.5°C | 1.8°C | 10.7°C | -4.9°C | 47 mm | 93% | 3.9 m/s | 0.8 |
| 1995 | 6.9°C | 4.1°C | 1.3°C | 11.4°C | -3.2°C | 103 mm | 93% | 5 m/s | 0.8 |
| 1994 | 7.0°C | 4.3°C | 1.5°C | 11.3°C | -3.3°C | 73 mm | 93% | 4.5 m/s | 0.9 |
| 1993 | 8.1°C | 5.0°C | 1.8°C | 12.9°C | -6.6°C | 66 mm | 92% | 4.7 m/s | 0.7 |
| 1992 | 5.7°C | 3.2°C | 0.7°C | 11.2°C | -4.7°C | 39 mm | 93% | 3 m/s | 1 |
| 1991 | 6.1°C | 3.3°C | 0.4°C | 11.3°C | -2.5°C | 51 mm | 90% | 3.7 m/s | 0.9 |
| 1990 | 8.5°C | 5.8°C | 3.2°C | 11.7°C | -1.0°C | 62 mm | 93% | 4.8 m/s | 0.8 |
| 1989 | 7.8°C | 4.8°C | 1.8°C | 11.2°C | -2.3°C | 31 mm | 94% | 3.3 m/s | 1 |
| 1988 🌧️ | 7.1°C | 4.9°C | 2.6°C | 12.3°C | -2.3°C | 116 mm | 94% | 4.2 m/s | 0.7 |
| 1987 ❄️ | 1.8°C | -0.6°C | -3.0°C | 8.7°C | -8.7°C | 30 mm | 92% | 2.8 m/s | 0.7 |
| 1986 | 4.8°C | 2.3°C | -0.3°C | 10.1°C | -4.7°C | 78 mm | 92% | 4.7 m/s | 0.8 |
| 1985 | 2.3°C | -0.3°C | -2.9°C | 10.2°C | -8.3°C | 56 mm | 94% | 3.3 m/s | 1.1 |
| 1984 | 5.5°C | 2.7°C | -0.1°C | 11.8°C | -4.9°C | 91 mm | 91% | 4.8 m/s | 0.8 |
| 1983 | 8.4°C | 5.4°C | 2.5°C | 12.7°C | -3.3°C | 56 mm | 92% | 5.2 m/s | — |
| 1982 | 5.2°C | 2.4°C | -0.3°C | 10.8°C | -8.6°C | 60 mm | 94% | 3.5 m/s | — |
| 1981 | 6.1°C | 3.5°C | 0.9°C | 10.2°C | -3.7°C | 47 mm | 93% | 3.8 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 6.4°C with lows near 1°C (mean 3.7°C), based on 45 years of NASA POWER data.
January averages 60 mm of rainfall in Welwyn Garden City, about average for rainfall. The wettest on record was 116 mm in 1988.
The hottest January reached 13.4°C in 2016. The coldest dipped to -8.7°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 1°C. Daytime highs moved from 5.5°C to 6.6°C and overnight lows from 0°C to 0.8°C over the same span.
January is one of the cooler months of the year in Welwyn Garden City and about average for rainfall, so plan for around 6.4°C daytime highs and 1°C at night.
Yes — January is the coldest month of the year in Welwyn Garden City, averaging 3.7°C.
For January in Welwyn Garden City, pack warm layers and a jacket for chilly mornings, with typical highs of 6.4°C and lows of 1°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 93% — quite humid.
Average wind speed in January is 3.9 m/s. The windiest January on record averaged 5.2 m/s (1983).
The wettest January on record was 1988 with 116 mm. On average, January sees 60 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 Welwyn Garden City 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.
