January is one of the cooler months of the year in Dorchester, with average highs near 8.7°C and lows around 6.3°C (mean 7.5°C). It is a relatively wet time of year, averaging 97 mm of rainfall and 86% relative humidity across the period.
January is one of the cooler months of the year in Dorchester. Across 45 years of records, the warmest January in Dorchester was 2007 — when the month averaged 9.3°C — while the coldest was 1987 at 3.4°C. Typical January days reach 8.7°C with nights near 6.3°C. The long-term trend is warming, about 0.2°C per decade.
January is a relatively wet time of year in Dorchester, averaging 97 mm of rainfall. The wettest January on record was 2016 with 192 mm, while the driest was 1997 at 20 mm.
Relative humidity in Dorchester during January averages 86%. The most humid January was 1997 at 91%, and the least humid was 1984 at 83%.
January receives about 0.8 kWh/m²/day of solar energy in Dorchester. The sunniest Januarys were 1985, 2000 and 2003 at 1 kWh/m²/day, and the cloudiest were 1995, 2002 and 2013, among others at 0.7.
Average wind speed in Dorchester during January is 6.9 m/s. The windiest January was 1984 at 8.6 m/s, while the calmest was 2022 at 5.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 6.7°C | 7.6°C | 7.8°C | 7.5°C | 7.8°C | +1.1°C |
| Avg High | 8.1°C | 8.8°C | 9.0°C | 8.8°C | 9.0°C | +0.9°C |
| Avg Low | 5.4°C | 6.4°C | 6.7°C | 6.3°C | 6.5°C | +1.1°C |
| Avg Rain | 94 mm | 96 mm | 82 mm | 106 mm | 115 mm | +21 mm |
January temperatures in Dorchester have risen by about 0.9°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -4.1°C (1987) to a record high of 13.1°C (2007).
Rainfall in January is a relatively wet time of year, averaging 97 mm, with a wettest year of 192 mm.
A quieter season to visit Dorchester
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Dorchester. That said, January — with days averaging 8.7°C and nights around 6.3°C (mean 7.5°C) and higher rainfall (97 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 | 9.0°C | 7.7°C | 6.4°C | 12.7°C | 2.8°C | 154 mm | 84% | 5.8 m/s | 0.9 |
| 2024 | 8.6°C | 7.5°C | 6.4°C | 13.1°C | 2.2°C | 104 mm | 84% | 6.7 m/s | 0.9 |
| 2023 | 9.1°C | 7.9°C | 6.8°C | 12.4°C | 3.2°C | 143 mm | 85% | 6.9 m/s | 0.9 |
| 2022 | 9.5°C | 8.1°C | 6.7°C | 12.4°C | 3.8°C | 47 mm | 86% | 5.2 m/s | 0.9 |
| 2021 | 7.9°C | 6.6°C | 5.3°C | 11.2°C | 2.4°C | 136 mm | 89% | 6.6 m/s | 0.8 |
| 2020 | 9.9°C | 8.7°C | 7.6°C | 12.8°C | 4.2°C | 104 mm | 88% | 6.5 m/s | 0.8 |
| 2019 | 8.2°C | 7.1°C | 5.9°C | 10.7°C | 3.2°C | 63 mm | 84% | 5.5 m/s | 0.9 |
| 2018 | 10.0°C | 8.5°C | 7.0°C | 12.9°C | 3.8°C | 119 mm | 87% | 7.5 m/s | 0.9 |
| 2017 | 8.7°C | 7.6°C | 6.4°C | 11.1°C | 3.1°C | 87 mm | 84% | 5.7 m/s | 0.9 |
| 2016 🌧️ | 9.9°C | 8.8°C | 7.7°C | 12.2°C | 4.6°C | 192 mm | 84% | 7.8 m/s | 0.8 |
| 2015 | 9.6°C | 7.9°C | 6.2°C | 12.6°C | 3.0°C | 141 mm | 84% | 7.4 m/s | 0.9 |
| 2014 | 10.1°C | 8.8°C | 7.6°C | 12.3°C | 4.4°C | 132 mm | 85% | 7.4 m/s | 0.8 |
| 2013 | 8.4°C | 7.3°C | 6.3°C | 11.7°C | 1.1°C | 109 mm | 87% | 6.2 m/s | 0.7 |
| 2012 | 9.6°C | 8.5°C | 7.3°C | 12.4°C | 2.7°C | 55 mm | 85% | 6.8 m/s | 0.9 |
| 2011 | 7.3°C | 6.1°C | 4.9°C | 10.8°C | 1.2°C | 93 mm | 89% | 6.2 m/s | 0.8 |
| 2010 | 5.8°C | 4.5°C | 3.3°C | 9.9°C | 0.4°C | 68 mm | 88% | 5.8 m/s | 0.9 |
| 2009 | 7.6°C | 6.6°C | 5.5°C | 10.2°C | 0.4°C | 105 mm | 85% | 6.5 m/s | 0.8 |
| 2008 | 10.4°C | 9.1°C | 7.9°C | 12.1°C | 4.9°C | 114 mm | 86% | 7.7 m/s | 0.8 |
| 2007 🔥 | 10.5°C | 9.3°C | 8.2°C | 13.1°C | 2.9°C | 85 mm | 86% | 8.2 m/s | 0.8 |
| 2006 | 8.0°C | 7.0°C | 5.9°C | 11.0°C | 1.9°C | 33 mm | 87% | 6.2 m/s | 0.9 |
| 2005 | 9.7°C | 8.4°C | 7.2°C | 12.3°C | 3.3°C | 54 mm | 86% | 7.8 m/s | 0.9 |
| 2004 | 9.4°C | 8.2°C | 7.0°C | 12.1°C | 2.1°C | 118 mm | 87% | 7.4 m/s | 0.8 |
| 2003 | 8.1°C | 6.9°C | 5.8°C | 12.5°C | 1.2°C | 85 mm | 87% | 7.6 m/s | 1 |
| 2002 | 9.7°C | 8.6°C | 7.6°C | 12.2°C | 4.5°C | 77 mm | 88% | 7 m/s | 0.7 |
| 2001 | 8.1°C | 7.1°C | 6.0°C | 11.5°C | 3.3°C | 121 mm | 87% | 6.8 m/s | 0.9 |
| 2000 | 8.5°C | 7.3°C | 6.2°C | 11.1°C | 3.0°C | 30 mm | 85% | 6.1 m/s | 1 |
| 1999 | 9.8°C | 8.5°C | 7.2°C | 12.4°C | 2.5°C | 101 mm | 87% | 7.5 m/s | 0.9 |
| 1998 | 9.5°C | 8.2°C | 7.0°C | 12.4°C | 3.2°C | 119 mm | 86% | 8.2 m/s | 0.8 |
| 1997 | 5.5°C | 4.5°C | 3.5°C | 8.6°C | -1.5°C | 20 mm | 91% | 5.7 m/s | 0.8 |
| 1996 | 8.8°C | 7.7°C | 6.7°C | 11.5°C | -1.0°C | 87 mm | 91% | 7.4 m/s | 0.8 |
| 1995 | 9.6°C | 8.1°C | 6.6°C | 11.6°C | 2.8°C | 156 mm | 86% | 8.4 m/s | 0.7 |
| 1994 | 9.2°C | 7.9°C | 6.6°C | 11.7°C | 2.8°C | 122 mm | 87% | 7.2 m/s | 0.9 |
| 1993 | 10.1°C | 8.7°C | 7.3°C | 12.3°C | 4.3°C | 97 mm | 87% | 7.6 m/s | 0.7 |
| 1992 | 7.5°C | 6.4°C | 5.2°C | 11.1°C | 2.2°C | 33 mm | 87% | 5.6 m/s | 0.9 |
| 1991 | 7.9°C | 6.6°C | 5.3°C | 11.9°C | 1.7°C | 102 mm | 84% | 6.7 m/s | 0.8 |
| 1990 | 10.4°C | 9.2°C | 8.1°C | 12.1°C | 5.4°C | 122 mm | 88% | 7.6 m/s | 0.8 |
| 1989 | 9.9°C | 8.6°C | 7.4°C | 12.2°C | 5.2°C | 39 mm | 85% | 5.5 m/s | 0.9 |
| 1988 | 9.5°C | 8.3°C | 7.0°C | 12.4°C | 4.7°C | 164 mm | 87% | 7.3 m/s | 0.9 |
| 1987 ❄️ | 4.6°C | 3.4°C | 2.3°C | 11.7°C | -4.1°C | 32 mm | 84% | 6.2 m/s | 0.8 |
| 1986 | 8.2°C | 6.8°C | 5.4°C | 11.4°C | 2.5°C | 126 mm | 85% | 7.6 m/s | 0.7 |
| 1985 | 5.5°C | 4.1°C | 2.8°C | 10.5°C | -1.2°C | 89 mm | 88% | 6.4 m/s | 1 |
| 1984 | 8.9°C | 7.3°C | 5.7°C | 12.7°C | 1.7°C | 162 mm | 83% | 8.6 m/s | 0.8 |
| 1983 | 9.8°C | 8.5°C | 7.3°C | 12.1°C | 3.6°C | 89 mm | 87% | 7.7 m/s | — |
| 1982 | 7.4°C | 6.3°C | 5.2°C | 11.2°C | 0.3°C | 98 mm | 90% | 6.5 m/s | — |
| 1981 | 8.8°C | 7.4°C | 5.9°C | 11.0°C | 1.8°C | 47 mm | 87% | 6.1 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 8.7°C with lows near 6.3°C (mean 7.5°C), based on 45 years of NASA POWER data.
January averages 97 mm of rainfall in Dorchester, a relatively wet time of year. The wettest on record was 192 mm in 2016.
The hottest January reached 13.1°C in 2007. The coldest dipped to -4.1°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.9°C. Daytime highs moved from 8.1°C to 8.8°C and overnight lows from 5.4°C to 6.3°C over the same span.
January is one of the cooler months of the year in Dorchester and a relatively wet time of year, so plan for around 8.7°C daytime highs and 6.3°C at night.
Not quite — January is the 2nd coolest month in Dorchester, averaging 7.5°C.
For January in Dorchester, pack warm layers and a jacket for chilly mornings, with typical highs of 8.7°C and lows of 6.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 86% — quite humid.
Average wind speed in January is 6.9 m/s. The windiest January on record averaged 8.6 m/s (1984).
The wettest January on record was 2016 with 192 mm. On average, January sees 97 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 Dorchester 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.
