January is one of the cooler months of the year in Williamsport, with average highs near -1.7°C and lows around -9.4°C (mean -5.5°C). It is one of the drier months, averaging 65 mm of rainfall and 90% relative humidity across the period.
January is one of the cooler months of the year in Williamsport. Across 45 years of records, the warmest January in Williamsport was 2023 — when the month averaged -0.6°C — while the coldest was 1994 at -11.7°C. Typical January days reach -1.7°C with nights near -9.4°C. The long-term trend is warming, about 0.5°C per decade.
January is one of the drier months in Williamsport, averaging 65 mm of rainfall. The wettest January on record was 1996 with 158 mm, while the driest was 1981 at 20 mm.
Relative humidity in Williamsport during January averages 90%. The most humid January was 1984 at 99%, and the least humid was 2025 at 82%.
January receives about 1.6 kWh/m²/day of solar energy in Williamsport. The sunniest January was 2022 at 2 kWh/m²/day, and the cloudiest was 2023 at 1.3.
Average wind speed in Williamsport during January is 0.6 m/s. The windiest January was 1997 at 0.8 m/s, while the calmest were 1984 and 2011 at 0.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -7.2°C | -5.1°C | -5.3°C | -5.7°C | -4.1°C | +3.1°C |
| Avg High | -3.2°C | -1.2°C | -1.5°C | -1.9°C | -0.5°C | +2.7°C |
| Avg Low | -11.2°C | -9.1°C | -9.1°C | -9.5°C | -7.7°C | +3.5°C |
| Avg Rain | 44 mm | 84 mm | 68 mm | 63 mm | 66 mm | +22 mm |
January temperatures in Williamsport have risen by about 3.9°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -28.8°C (1984) to a record high of 16.4°C (1998).
Rainfall in January is one of the drier months, averaging 65 mm, with a wettest year of 158 mm.
A quieter season to visit Williamsport
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Williamsport. That said, January — with days averaging -1.7°C and nights around -9.4°C (mean -5.5°C) and moderate rainfall (65 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 | -2.9°C | -6.3°C | -9.8°C | 3.7°C | -19.9°C | 25 mm | 82% | 0.7 m/s | 1.7 |
| 2024 | 0.2°C | -3.4°C | -6.9°C | 10.5°C | -15.4°C | 142 mm | 91% | 0.6 m/s | 1.4 |
| 2023 🔥 | 2.5°C | -0.6°C | -3.7°C | 11.1°C | -10.0°C | 81 mm | 92% | 0.6 m/s | 1.3 |
| 2022 | -3.4°C | -7.7°C | -12.0°C | 9.1°C | -21.5°C | 43 mm | 88% | 0.6 m/s | 2 |
| 2021 | -0.9°C | -4.1°C | -7.2°C | 3.0°C | -12.7°C | 47 mm | 91% | 0.6 m/s | 1.5 |
| 2020 | 1.7°C | -2.5°C | -6.7°C | 15.7°C | -15.8°C | 58 mm | 88% | 0.6 m/s | 1.6 |
| 2019 | -2.7°C | -6.7°C | -10.8°C | 7.9°C | -23.3°C | 93 mm | 92% | 0.6 m/s | 1.7 |
| 2018 | -2.3°C | -6.6°C | -10.9°C | 15.6°C | -20.6°C | 78 mm | 88% | 0.6 m/s | 1.9 |
| 2017 | 0.5°C | -2.5°C | -5.6°C | 11.2°C | -15.6°C | 84 mm | 89% | 0.6 m/s | 1.4 |
| 2016 | -0.8°C | -4.5°C | -8.3°C | 9.5°C | -15.0°C | 46 mm | 84% | 0.7 m/s | 1.6 |
| 2015 | -3.5°C | -7.5°C | -11.5°C | 5.3°C | -17.4°C | 39 mm | 84% | 0.7 m/s | 1.7 |
| 2014 | -4.2°C | -8.5°C | -12.9°C | 5.0°C | -23.1°C | 46 mm | 86% | 0.7 m/s | 1.8 |
| 2013 | -0.9°C | -4.6°C | -8.2°C | 14.0°C | -19.1°C | 63 mm | 91% | 0.6 m/s | 1.6 |
| 2012 | 0.6°C | -3.1°C | -6.8°C | 8.3°C | -16.1°C | 70 mm | 90% | 0.6 m/s | 1.7 |
| 2011 | -3.5°C | -7.0°C | -10.4°C | 4.1°C | -20.2°C | 32 mm | 90% | 0.5 m/s | 1.6 |
| 2010 | -1.9°C | -5.7°C | -9.4°C | 9.3°C | -17.4°C | 77 mm | 89% | 0.6 m/s | 1.6 |
| 2009 | -5.1°C | -9.0°C | -12.9°C | 2.1°C | -24.7°C | 51 mm | 94% | 0.6 m/s | 1.8 |
| 2008 | 0.3°C | -3.5°C | -7.4°C | 14.9°C | -13.7°C | 51 mm | 89% | 0.6 m/s | 1.7 |
| 2007 | 1.0°C | -2.6°C | -6.3°C | 13.7°C | -16.2°C | 85 mm | 88% | 0.6 m/s | 1.5 |
| 2006 | 2.6°C | -1.3°C | -5.3°C | 10.4°C | -13.6°C | 114 mm | 92% | 0.6 m/s | 1.6 |
| 2005 | -2.6°C | -6.5°C | -10.4°C | 12.6°C | -20.8°C | 129 mm | 94% | 0.6 m/s | 1.5 |
| 2004 | -5.9°C | -9.3°C | -12.6°C | 12.1°C | -21.1°C | 67 mm | 94% | 0.7 m/s | 1.7 |
| 2003 | -5.5°C | -8.9°C | -12.4°C | 1.1°C | -20.3°C | 50 mm | 95% | 0.6 m/s | 1.7 |
| 2002 | 2.4°C | -1.6°C | -5.6°C | 13.2°C | -15.1°C | 48 mm | 89% | 0.6 m/s | 1.6 |
| 2001 | -0.1°C | -4.0°C | -7.9°C | 4.4°C | -13.3°C | 28 mm | 89% | 0.6 m/s | 1.7 |
| 2000 | -2.3°C | -6.0°C | -9.8°C | 11.7°C | -18.5°C | 61 mm | 87% | 0.7 m/s | 1.7 |
| 1999 | -1.5°C | -6.0°C | -10.4°C | 13.0°C | -19.8°C | 131 mm | 92% | 0.6 m/s | 1.5 |
| 1998 | 2.2°C | -1.6°C | -5.3°C | 16.4°C | -15.6°C | 102 mm | 93% | 0.6 m/s | 1.4 |
| 1997 | -2.3°C | -6.2°C | -10.1°C | 9.5°C | -20.3°C | 41 mm | 88% | 0.8 m/s | 1.5 |
| 1996 🌧️ | -3.8°C | -7.9°C | -12.0°C | 9.8°C | -22.5°C | 158 mm | 94% | 0.7 m/s | 1.5 |
| 1995 | 0.6°C | -2.9°C | -6.5°C | 13.3°C | -16.6°C | 83 mm | 90% | 0.6 m/s | 1.7 |
| 1994 ❄️ | -7.4°C | -11.7°C | -16.0°C | 0.1°C | -28.5°C | 95 mm | 99% | 0.6 m/s | 1.6 |
| 1993 | -0.1°C | -3.9°C | -7.8°C | 9.5°C | -15.5°C | 53 mm | 89% | 0.6 m/s | 1.4 |
| 1992 | -0.2°C | -4.0°C | -7.8°C | 9.6°C | -15.1°C | 53 mm | 87% | 0.7 m/s | 1.5 |
| 1991 | -1.5°C | -5.5°C | -9.5°C | 4.6°C | -16.7°C | 51 mm | 89% | 0.6 m/s | 1.7 |
| 1990 | 1.8°C | -1.7°C | -5.3°C | 9.6°C | -11.2°C | 75 mm | 90% | 0.6 m/s | 1.6 |
| 1989 | 0.9°C | -3.6°C | -8.2°C | 8.7°C | -18.1°C | 31 mm | 86% | 0.6 m/s | 1.5 |
| 1988 | -3.4°C | -7.1°C | -10.8°C | 6.6°C | -18.0°C | 34 mm | 89% | 0.6 m/s | 1.7 |
| 1987 | -3.4°C | -7.2°C | -11.0°C | 3.5°C | -26.7°C | 70 mm | 97% | 0.6 m/s | 1.5 |
| 1986 | -1.4°C | -5.4°C | -9.4°C | 8.8°C | -20.3°C | 57 mm | 87% | 0.6 m/s | 1.5 |
| 1985 | -4.0°C | -7.3°C | -10.7°C | 10.5°C | -25.3°C | 22 mm | 86% | 0.7 m/s | 1.9 |
| 1984 | -5.7°C | -10.6°C | -15.4°C | 0.4°C | -28.8°C | 34 mm | 99% | 0.5 m/s | 1.5 |
| 1983 | -1.0°C | -4.7°C | -8.4°C | 4.6°C | -16.9°C | 43 mm | 88% | 0.6 m/s | — |
| 1982 | -6.0°C | -10.1°C | -14.2°C | 2.4°C | -23.4°C | 84 mm | 91% | 0.7 m/s | — |
| 1981 | -4.8°C | -8.7°C | -12.6°C | 4.1°C | -21.8°C | 20 mm | 89% | 0.6 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around -1.7°C with lows near -9.4°C (mean -5.5°C), based on 45 years of NASA POWER data.
January averages 65 mm of rainfall in Williamsport, one of the drier months. The wettest on record was 158 mm in 1996.
The hottest January reached 16.4°C in 1998. The coldest dipped to -28.8°C in 1984.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 3.9°C. Daytime highs moved from -4.3°C to -0.9°C and overnight lows from -12.3°C to -7.9°C over the same span.
January is one of the cooler months of the year in Williamsport and one of the drier months, so plan for around -1.7°C daytime highs and -9.4°C at night.
Yes — January is the coldest month of the year in Williamsport, averaging -5.5°C.
For January in Williamsport, pack warm layers and a jacket for chilly mornings, with typical highs of -1.7°C and lows of -9.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 90% — quite humid.
Average wind speed in January is 0.6 m/s. The windiest January on record averaged 0.8 m/s (1997).
The wettest January on record was 1996 with 158 mm. On average, January sees 65 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 Williamsport 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.
