January is one of the warmer months of the year in Sunbury, with average highs near 28°C and lows around 12.6°C (mean 20.3°C). It is about average for rainfall, averaging 52 mm of rainfall and 60% relative humidity across the period.
January is one of the warmer months of the year in Sunbury. Across 45 years of records, the warmest January in Sunbury was 2022 — when the month averaged 23.5°C — while the coldest was 1992 at 16.3°C. Typical January days reach 28°C with nights near 12.6°C. The long-term trend is warming, about 0.4°C per decade.
January is about average for rainfall in Sunbury, averaging 52 mm of rainfall. The wettest January on record was 2024 with 161 mm, while the driest was 2009 at 4 mm.
Relative humidity in Sunbury during January averages 60%. The most humid January was 2024 at 76%, and the least humid was 2009 at 50%.
January receives about 7.2 kWh/m²/day of solar energy in Sunbury. The sunniest January was 2009 at 8.3 kWh/m²/day, and the cloudiest was 2016 at 6.4.
Average wind speed in Sunbury during January is 2.6 m/s. The windiest Januarys were 1990 and 2012 at 3 m/s, while the calmest was 1993 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 19.6°C | 19.7°C | 20.5°C | 21.0°C | 20.7°C | +1.1°C |
| Avg High | 27.5°C | 27.2°C | 28.4°C | 28.7°C | 27.9°C | +0.4°C |
| Avg Low | 11.7°C | 12.3°C | 12.7°C | 13.2°C | 13.5°C | +1.8°C |
| Avg Rain | 50 mm | 53 mm | 34 mm | 49 mm | 89 mm | +39 mm |
January temperatures in Sunbury have risen by about 0.6°C between 1981–1985 and 2021–2025.
January has ranged from a record low of 4.7°C (1987) to a record high of 44.8°C (1982).
Rainfall in January is about average for rainfall, averaging 52 mm, with a wettest year of 161 mm.
One of the best times to visit Sunbury
January is one of the best times to visit Sunbury. Expect days averaging 28°C and nights around 12.6°C (mean 20.3°C) — warmer than Sunbury's yearly average — with moderate rainfall (52 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 | 29.1°C | 21.4°C | 13.7°C | 39.7°C | 8.5°C | 34 mm | 57% | 2.6 m/s | 7.3 |
| 2024 🌧️ | 25.4°C | 19.3°C | 13.1°C | 30.9°C | 8.9°C | 161 mm | 76% | 2.3 m/s | 6.7 |
| 2023 | 27.6°C | 20.4°C | 13.3°C | 35.7°C | 8.9°C | 52 mm | 65% | 2.4 m/s | 7.1 |
| 2022 🔥 | 30.9°C | 23.5°C | 16.0°C | 37.5°C | 11.2°C | 71 mm | 61% | 2.4 m/s | 7.2 |
| 2021 | 26.4°C | 19.5°C | 12.6°C | 36.8°C | 7.1°C | 121 mm | 66% | 2.6 m/s | 6.9 |
| 2020 | 28.1°C | 20.3°C | 12.5°C | 41.5°C | 7.9°C | 93 mm | 62% | 2.5 m/s | 6.8 |
| 2019 | 32.5°C | 23.4°C | 14.2°C | 44.3°C | 8.4°C | 16 mm | 55% | 2.6 m/s | 7.9 |
| 2018 | 30.0°C | 22.0°C | 14.0°C | 41.4°C | 9.7°C | 56 mm | 60% | 2.6 m/s | 7.3 |
| 2017 | 28.7°C | 20.9°C | 13.0°C | 38.5°C | 8.4°C | 41 mm | 59% | 2.5 m/s | 7.5 |
| 2016 | 27.5°C | 20.6°C | 13.7°C | 41.8°C | 8.4°C | 82 mm | 64% | 2.5 m/s | 6.4 |
| 2015 | 27.3°C | 19.8°C | 12.4°C | 38.8°C | 8.0°C | 50 mm | 62% | 2.8 m/s | 6.7 |
| 2014 | 30.0°C | 21.7°C | 13.4°C | 43.2°C | 6.7°C | 20 mm | 52% | 2.9 m/s | 7.5 |
| 2013 | 29.2°C | 20.8°C | 12.4°C | 39.9°C | 8.7°C | 12 mm | 51% | 2.9 m/s | 7.8 |
| 2012 | 28.0°C | 20.8°C | 13.5°C | 38.3°C | 9.2°C | 38 mm | 58% | 3 m/s | 7.2 |
| 2011 | 25.4°C | 19.3°C | 13.3°C | 35.4°C | 6.8°C | 138 mm | 73% | 2.3 m/s | 6.8 |
| 2010 | 28.6°C | 20.3°C | 11.9°C | 41.2°C | 8.0°C | 41 mm | 58% | 2.8 m/s | 7.5 |
| 2009 | 30.6°C | 21.4°C | 12.1°C | 43.3°C | 5.9°C | 4 mm | 50% | 2.6 m/s | 8.3 |
| 2008 | 29.1°C | 21.2°C | 13.3°C | 38.7°C | 9.3°C | 48 mm | 61% | 2.6 m/s | 7.4 |
| 2007 | 28.4°C | 21.1°C | 13.7°C | 39.9°C | 8.6°C | 36 mm | 59% | 2.7 m/s | 7 |
| 2006 | 29.5°C | 21.5°C | 13.5°C | 41.2°C | 8.9°C | 54 mm | 60% | 2.8 m/s | 7.3 |
| 2005 | 27.4°C | 20.0°C | 12.6°C | 36.2°C | 6.8°C | 37 mm | 62% | 2.4 m/s | 7 |
| 2004 | 26.4°C | 18.5°C | 10.6°C | 36.6°C | 6.0°C | 36 mm | 59% | 2.7 m/s | 7.1 |
| 2003 | 28.7°C | 20.5°C | 12.3°C | 42.3°C | 8.1°C | 13 mm | 53% | 2.9 m/s | 7.3 |
| 2002 | 26.9°C | 19.4°C | 11.8°C | 38.2°C | 8.1°C | 38 mm | 61% | 2.9 m/s | 6.7 |
| 2001 | 31.2°C | 22.9°C | 14.6°C | 41.5°C | 9.7°C | 29 mm | 55% | 2.7 m/s | 6.8 |
| 2000 | 25.4°C | 18.7°C | 12.0°C | 34.7°C | 6.2°C | 44 mm | 63% | 2.7 m/s | 6.7 |
| 1999 | 30.1°C | 22.0°C | 14.0°C | 40.8°C | 11.4°C | 38 mm | 63% | 2.5 m/s | 7.2 |
| 1998 | 28.7°C | 20.9°C | 13.2°C | 39.1°C | 9.1°C | 47 mm | 60% | 2.6 m/s | 7.1 |
| 1997 | 28.6°C | 20.6°C | 12.6°C | 39.7°C | 8.2°C | 43 mm | 55% | 2.9 m/s | 7.3 |
| 1996 | 26.2°C | 18.7°C | 11.3°C | 36.5°C | 7.2°C | 58 mm | 65% | 2.5 m/s | 6.9 |
| 1995 | 28.6°C | 21.2°C | 13.8°C | 37.4°C | 6.9°C | 86 mm | 62% | 2.5 m/s | 6.7 |
| 1994 | 25.2°C | 17.5°C | 9.9°C | 39.0°C | 5.0°C | 45 mm | 64% | 2.7 m/s | 7.3 |
| 1993 | 25.9°C | 19.1°C | 12.4°C | 36.2°C | 7.4°C | 90 mm | 71% | 2.2 m/s | 6.8 |
| 1992 ❄️ | 22.5°C | 16.3°C | 10.1°C | 36.7°C | 6.5°C | 28 mm | 69% | 2.8 m/s | 7.1 |
| 1991 | 27.7°C | 20.3°C | 13.0°C | 39.7°C | 9.0°C | 92 mm | 62% | 2.7 m/s | 7.1 |
| 1990 | 28.5°C | 20.5°C | 12.5°C | 39.3°C | 8.0°C | 7 mm | 53% | 3 m/s | 7.3 |
| 1989 | 25.9°C | 18.8°C | 11.7°C | 36.0°C | 7.1°C | 53 mm | 62% | 2.5 m/s | 7.2 |
| 1988 | 29.7°C | 21.5°C | 13.3°C | 39.4°C | 6.9°C | 72 mm | 57% | 2.5 m/s | 7.4 |
| 1987 | 26.1°C | 18.1°C | 10.1°C | 36.1°C | 4.7°C | 49 mm | 59% | 2.4 m/s | 7.3 |
| 1986 | 24.3°C | 17.2°C | 10.0°C | 34.2°C | 7.2°C | 31 mm | 64% | 2.7 m/s | 7.4 |
| 1985 | 27.2°C | 19.2°C | 11.2°C | 41.3°C | 7.2°C | 23 mm | 54% | 2.9 m/s | 7.3 |
| 1984 | 25.2°C | 18.3°C | 11.4°C | 32.6°C | 6.9°C | 84 mm | 63% | 2.7 m/s | 6.7 |
| 1983 | 26.7°C | 18.4°C | 10.1°C | 40.6°C | 6.7°C | 30 mm | 52% | 2.6 m/s | — |
| 1982 | 30.3°C | 21.9°C | 13.5°C | 44.8°C | 8.0°C | 56 mm | 51% | 2.7 m/s | — |
| 1981 | 32.4°C | 23.4°C | 14.4°C | 41.6°C | 9.4°C | 50 mm | 53% | 2.8 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 28°C with lows near 12.6°C (mean 20.3°C), based on 45 years of NASA POWER data.
January averages 52 mm of rainfall in Sunbury, about average for rainfall. The wettest on record was 161 mm in 2024.
The hottest January reached 44.8°C in 1982. The coldest dipped to 4.7°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.6°C — but days and nights have moved in opposite directions. Overnight lows rose from 12.1°C to 13.7°C while daytime highs eased from 28.4°C to 27.9°C, narrowing the gap between day and night.
January is one of the warmer months of the year in Sunbury and about average for rainfall, so plan for around 28°C daytime highs and 12.6°C at night.
Not quite — January is the 11th coolest month in Sunbury, averaging 20.3°C.
For January in Sunbury, pack light layers you can adjust through the day, with typical highs of 28°C and lows of 12.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 60% — moderately humid.
Average wind speed in January is 2.6 m/s. The windiest January on record averaged 3 m/s (1990).
The wettest January on record was 2024 with 161 mm. On average, January sees 52 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 Sunbury 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.
