January is one of the cooler months of the year in Brentwood, with average highs near 7°C and lows around -2.6°C (mean 2.2°C). It is about average for rainfall, averaging 104 mm of rainfall and 85% relative humidity across the period.
January is one of the cooler months of the year in Brentwood. Across 45 years of records, the warmest January in Brentwood was 2023 — when the month averaged 6.6°C — while the coldest was 1985 at -3°C. Typical January days reach 7°C with nights near -2.6°C. The long-term trend is warming, about 0.5°C per decade.
January is about average for rainfall in Brentwood, averaging 104 mm of rainfall. The wettest January on record was 1999 with 232 mm, while the driest was 1986 at 16 mm.
Relative humidity in Brentwood during January averages 85%. The most humid January was 1991 at 91%, and the least humid was 1981 at 77%.
January receives about 2.3 kWh/m²/day of solar energy in Brentwood. The sunniest Januarys were 1986 and 2014 at 2.7 kWh/m²/day, and the cloudiest were 1991, 1994 and 2024 at 1.9.
Average wind speed in Brentwood during January is 2.2 m/s. The windiest January was 1982 at 2.7 m/s, while the calmest was 1984 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 0.5°C | 2.8°C | 2.8°C | 2.1°C | 3.0°C | +2.5°C |
| Avg High | 5.3°C | 7.5°C | 7.7°C | 6.9°C | 7.9°C | +2.6°C |
| Avg Low | -4.3°C | -1.8°C | -2.0°C | -2.7°C | -2.0°C | +2.3°C |
| Avg Rain | 85 mm | 118 mm | 101 mm | 95 mm | 134 mm | +49 mm |
January temperatures in Brentwood have risen by about 3.2°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -24.7°C (1994) to a record high of 23.4°C (2022).
Rainfall in January is about average for rainfall, averaging 104 mm, with a wettest year of 232 mm.
A quieter season to visit Brentwood
If your dates are flexible, the more temperate months of September and June tend to be the most comfortable for visiting Brentwood. That said, January — with days averaging 7°C and nights around -2.6°C (mean 2.2°C) and higher rainfall (104 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 | 5.8°C | 0.8°C | -4.3°C | 16.7°C | -14.4°C | 87 mm | 79% | 1.9 m/s | 2.5 |
| 2024 | 6.2°C | 1.1°C | -4.0°C | 17.0°C | -16.2°C | 149 mm | 83% | 2.3 m/s | 1.9 |
| 2023 🔥 | 11.5°C | 6.6°C | 1.6°C | 21.0°C | -4.8°C | 156 mm | 87% | 2.2 m/s | 2.2 |
| 2022 | 5.4°C | 0.3°C | -4.8°C | 23.4°C | -11.5°C | 164 mm | 86% | 2.2 m/s | 2.6 |
| 2021 | 8.5°C | 3.7°C | -1.2°C | 21.4°C | -5.4°C | 80 mm | 85% | 2 m/s | 2.4 |
| 2020 | 9.8°C | 5.3°C | 0.8°C | 20.3°C | -8.2°C | 166 mm | 89% | 2.1 m/s | 2 |
| 2019 | 7.6°C | 3.0°C | -1.6°C | 18.6°C | -11.4°C | 115 mm | 86% | 2.2 m/s | 2.4 |
| 2018 | 5.3°C | 0.2°C | -5.0°C | 18.2°C | -15.2°C | 57 mm | 82% | 2.2 m/s | 2.6 |
| 2017 | 11.0°C | 6.5°C | 2.0°C | 20.6°C | -12.8°C | 94 mm | 85% | 2.2 m/s | 2.1 |
| 2016 | 5.9°C | 1.2°C | -3.4°C | 17.6°C | -11.2°C | 56 mm | 85% | 2.1 m/s | 2.4 |
| 2015 | 6.7°C | 1.8°C | -3.1°C | 16.7°C | -16.6°C | 61 mm | 83% | 2 m/s | 2.4 |
| 2014 | 4.0°C | -1.2°C | -6.4°C | 13.8°C | -15.1°C | 60 mm | 78% | 2.5 m/s | 2.7 |
| 2013 | 8.7°C | 3.9°C | -0.9°C | 21.4°C | -7.2°C | 174 mm | 86% | 2.2 m/s | 2.1 |
| 2012 | 10.6°C | 5.1°C | -0.4°C | 17.5°C | -6.8°C | 125 mm | 85% | 2.3 m/s | 2.2 |
| 2011 | 5.7°C | 1.0°C | -3.7°C | 16.9°C | -8.8°C | 78 mm | 82% | 1.8 m/s | 2.2 |
| 2010 | 3.6°C | -0.5°C | -4.6°C | 16.0°C | -12.4°C | 125 mm | 86% | 2 m/s | 2.3 |
| 2009 | 6.3°C | 1.3°C | -3.7°C | 18.3°C | -15.6°C | 112 mm | 84% | 2.1 m/s | 2.2 |
| 2008 | 6.2°C | 1.3°C | -3.6°C | 19.6°C | -12.9°C | 94 mm | 82% | 2.2 m/s | 2.3 |
| 2007 | 8.4°C | 3.8°C | -0.8°C | 18.5°C | -11.4°C | 89 mm | 84% | 2.1 m/s | 2.3 |
| 2006 | 12.0°C | 6.4°C | 0.9°C | 21.2°C | -4.3°C | 170 mm | 82% | 2.6 m/s | 2.4 |
| 2005 | 8.9°C | 4.7°C | 0.4°C | 18.7°C | -11.8°C | 119 mm | 89% | 2.4 m/s | 2.1 |
| 2004 | 7.7°C | 2.6°C | -2.4°C | 20.7°C | -10.4°C | 81 mm | 81% | 2.3 m/s | 2.5 |
| 2003 | 4.2°C | -0.5°C | -5.1°C | 14.9°C | -15.2°C | 38 mm | 84% | 2.1 m/s | 2.5 |
| 2002 | 9.6°C | 4.7°C | -0.1°C | 21.8°C | -9.5°C | 149 mm | 86% | 2.1 m/s | 2.5 |
| 2001 | 5.4°C | 0.9°C | -3.6°C | 17.1°C | -10.0°C | 83 mm | 85% | 1.8 m/s | 2.4 |
| 2000 | 8.2°C | 3.2°C | -1.9°C | 20.1°C | -10.9°C | 77 mm | 79% | 2.3 m/s | 2.3 |
| 1999 🌧️ | 9.1°C | 4.3°C | -0.5°C | 19.0°C | -12.8°C | 232 mm | 88% | 2.6 m/s | 2.1 |
| 1998 | 10.3°C | 5.7°C | 1.1°C | 20.7°C | -7.5°C | 123 mm | 89% | 1.8 m/s | 2 |
| 1997 | 6.3°C | 1.5°C | -3.3°C | 20.0°C | -15.7°C | 118 mm | 87% | 2.4 m/s | 2.3 |
| 1996 | 5.2°C | 0.8°C | -3.5°C | 18.0°C | -11.2°C | 111 mm | 88% | 2.5 m/s | 2.1 |
| 1995 | 7.4°C | 2.8°C | -1.8°C | 18.8°C | -12.5°C | 122 mm | 87% | 2.2 m/s | 2.1 |
| 1994 | 2.9°C | -1.6°C | -6.1°C | 13.1°C | -24.7°C | 129 mm | 88% | 2.1 m/s | 1.9 |
| 1993 | 9.0°C | 4.0°C | -1.0°C | 16.3°C | -6.2°C | 80 mm | 84% | 2.1 m/s | 2.1 |
| 1992 | 7.4°C | 2.9°C | -1.6°C | 13.8°C | -12.5°C | 79 mm | 89% | 1.9 m/s | 2.3 |
| 1991 | 6.9°C | 2.6°C | -1.7°C | 12.8°C | -8.9°C | 77 mm | 91% | 1.9 m/s | 1.9 |
| 1990 | 10.1°C | 5.1°C | 0.0°C | 17.2°C | -5.9°C | 108 mm | 86% | 2.2 m/s | 2.2 |
| 1989 | 9.9°C | 4.9°C | 0.0°C | 17.9°C | -4.9°C | 158 mm | 87% | 2 m/s | 2.3 |
| 1988 | 4.1°C | -0.4°C | -4.9°C | 18.0°C | -12.2°C | 98 mm | 85% | 2.3 m/s | 2.4 |
| 1987 | 5.6°C | 1.5°C | -2.7°C | 12.7°C | -13.2°C | 65 mm | 89% | 1.9 m/s | 2.2 |
| 1986 | 7.1°C | 1.7°C | -3.8°C | 18.3°C | -14.0°C | 16 mm | 78% | 2.2 m/s | 2.7 |
| 1985 ❄️ | 1.5°C | -3.0°C | -7.5°C | 17.2°C | -23.2°C | 78 mm | 88% | 2.4 m/s | 2.1 |
| 1984 | 3.4°C | -0.9°C | -5.3°C | 13.0°C | -20.0°C | 44 mm | 89% | 1.7 m/s | 2.3 |
| 1983 | 5.8°C | 1.6°C | -2.6°C | 12.7°C | -9.3°C | 73 mm | 88% | 2 m/s | — |
| 1982 | 5.1°C | -0.7°C | -6.5°C | 18.8°C | -22.6°C | 185 mm | 84% | 2.7 m/s | — |
| 1981 | 4.8°C | -0.5°C | -5.8°C | 15.8°C | -14.5°C | 45 mm | 77% | 1.9 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 7°C with lows near -2.6°C (mean 2.2°C), based on 45 years of NASA POWER data.
January averages 104 mm of rainfall in Brentwood, about average for rainfall. The wettest on record was 232 mm in 1999.
The hottest January reached 23.4°C in 2022. The coldest dipped to -24.7°C in 1994.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 3.2°C. Daytime highs moved from 4.1°C to 7.5°C and overnight lows from -5.5°C to -2.5°C over the same span.
January is one of the cooler months of the year in Brentwood and about average for rainfall, so plan for around 7°C daytime highs and -2.6°C at night.
Yes — January is the coldest month of the year in Brentwood, averaging 2.2°C.
For January in Brentwood, pack warm layers and a jacket for chilly mornings, with typical highs of 7°C and lows of -2.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 85% — quite humid.
Average wind speed in January is 2.2 m/s. The windiest January on record averaged 2.7 m/s (1982).
The wettest January on record was 1999 with 232 mm. On average, January sees 104 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 Brentwood 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.
