January is one of the cooler months of the year in Helena, with average highs near -2.1°C and lows around -12.5°C (mean -7.3°C). It is one of the drier months, averaging 30 mm of rainfall and 91% relative humidity across the period.
January is one of the cooler months of the year in Helena. Across 45 years of records, the warmest January in Helena was 1981 — when the month averaged -2.6°C — while the coldest was 2017 at -11.8°C. Typical January days reach -2.1°C with nights near -12.5°C. The long-term January temperature trend is broadly flat.
January is one of the drier months in Helena, averaging 30 mm of rainfall. The wettest January on record was 1996 with 56 mm, while the driest was 1985 at 12 mm.
Relative humidity in Helena during January averages 91%. The most humid Januarys were 1993 and 2010 at 97%, and the least humid was 1981 at 83%.
January receives about 1.5 kWh/m²/day of solar energy in Helena. The sunniest January was 2017 at 1.8 kWh/m²/day, and the cloudiest were 1989 and 2011 at 1.3.
Average wind speed in Helena during January is 1.5 m/s. The windiest January was 1990 at 1.9 m/s, while the calmest were 1981, 1995 and 2010 at 1.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -7.1°C | -8.0°C | -6.9°C | -7.6°C | -6.6°C | +0.5°C |
| Avg High | -1.9°C | -2.8°C | -1.8°C | -2.4°C | -1.4°C | +0.5°C |
| Avg Low | -12.4°C | -13.2°C | -12.1°C | -12.7°C | -11.8°C | +0.6°C |
| Avg Rain | 24 mm | 34 mm | 28 mm | 37 mm | 25 mm | +1 mm |
January temperatures in Helena have risen by about 0.3°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -33.2°C (2024) to a record high of 10.8°C (2024).
Rainfall in January is one of the drier months, averaging 30 mm, with a wettest year of 56 mm.
A quieter season to visit Helena
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Helena. That said, January — with days averaging -2.1°C and nights around -12.5°C (mean -7.3°C) and moderate rainfall (30 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 | -2.6°C | -8.1°C | -13.5°C | 3.1°C | -25.3°C | 25 mm | 90% | 1.4 m/s | 1.6 |
| 2024 | -2.0°C | -7.5°C | -13.0°C | 10.8°C | -33.2°C | 20 mm | 88% | 1.3 m/s | 1.4 |
| 2023 | -2.0°C | -7.1°C | -12.3°C | 3.1°C | -30.9°C | 29 mm | 92% | 1.3 m/s | 1.7 |
| 2022 | -1.2°C | -6.7°C | -12.1°C | 3.6°C | -24.6°C | 24 mm | 88% | 1.5 m/s | 1.6 |
| 2021 | 0.3°C | -4.8°C | -10.0°C | 4.1°C | -16.1°C | 20 mm | 85% | 1.5 m/s | 1.6 |
| 2020 | -0.7°C | -5.4°C | -10.2°C | 4.4°C | -21.5°C | 31 mm | 90% | 1.5 m/s | 1.4 |
| 2019 | -1.1°C | -6.5°C | -11.8°C | 2.1°C | -24.8°C | 39 mm | 92% | 1.5 m/s | 1.5 |
| 2018 | -1.6°C | -6.5°C | -11.4°C | 1.0°C | -20.7°C | 37 mm | 97% | 1.3 m/s | 1.5 |
| 2017 ❄️ | -6.0°C | -11.8°C | -17.6°C | 0.6°C | -27.7°C | 28 mm | 97% | 1.2 m/s | 1.8 |
| 2016 | -2.2°C | -7.4°C | -12.6°C | 2.1°C | -22.1°C | 27 mm | 97% | 1.3 m/s | 1.5 |
| 2015 | -0.7°C | -6.2°C | -11.7°C | 7.4°C | -23.2°C | 38 mm | 94% | 1.4 m/s | 1.6 |
| 2014 | -1.5°C | -6.3°C | -11.1°C | 2.3°C | -24.2°C | 43 mm | 90% | 1.7 m/s | 1.6 |
| 2013 | -3.2°C | -8.4°C | -13.5°C | 3.7°C | -24.2°C | 25 mm | 93% | 1.6 m/s | 1.6 |
| 2012 | -1.5°C | -6.3°C | -11.1°C | 3.4°C | -20.8°C | 48 mm | 88% | 1.7 m/s | 1.5 |
| 2011 | -3.4°C | -7.9°C | -12.5°C | 2.7°C | -27.3°C | 45 mm | 94% | 1.6 m/s | 1.3 |
| 2010 | -3.1°C | -8.6°C | -14.1°C | 0.7°C | -29.6°C | 41 mm | 97% | 1.1 m/s | 1.6 |
| 2009 | -2.1°C | -7.2°C | -12.3°C | 4.1°C | -25.2°C | 40 mm | 88% | 1.8 m/s | 1.5 |
| 2008 | -4.7°C | -11.0°C | -17.3°C | 0.7°C | -31.0°C | 40 mm | 95% | 1.6 m/s | 1.6 |
| 2007 | -3.5°C | -8.6°C | -13.8°C | 3.9°C | -26.5°C | 21 mm | 89% | 1.6 m/s | 1.7 |
| 2006 | 0.0°C | -4.8°C | -9.6°C | 4.0°C | -14.6°C | 29 mm | 89% | 1.7 m/s | 1.4 |
| 2005 | -1.4°C | -6.4°C | -11.5°C | 7.4°C | -22.9°C | 20 mm | 92% | 1.2 m/s | 1.6 |
| 2004 | -3.6°C | -8.7°C | -13.8°C | 1.0°C | -33.0°C | 36 mm | 97% | 1.2 m/s | 1.4 |
| 2003 | 1.2°C | -3.7°C | -8.7°C | 6.2°C | -16.7°C | 32 mm | 88% | 1.3 m/s | 1.4 |
| 2002 | -2.1°C | -6.5°C | -10.9°C | 3.3°C | -20.7°C | 25 mm | 87% | 1.6 m/s | 1.4 |
| 2001 | -0.2°C | -5.7°C | -11.1°C | 4.5°C | -15.8°C | 12 mm | 88% | 1.3 m/s | 1.6 |
| 2000 | -1.1°C | -6.5°C | -11.9°C | 2.2°C | -19.6°C | 25 mm | 87% | 1.5 m/s | 1.5 |
| 1999 | -2.2°C | -7.5°C | -12.8°C | 1.3°C | -23.2°C | 38 mm | 94% | 1.5 m/s | 1.5 |
| 1998 | -2.1°C | -7.6°C | -13.1°C | 3.0°C | -25.6°C | 40 mm | 93% | 1.4 m/s | 1.5 |
| 1997 | -4.8°C | -9.9°C | -14.9°C | 1.8°C | -30.4°C | 56 mm | 96% | 1.3 m/s | 1.4 |
| 1996 🌧️ | -6.2°C | -11.4°C | -16.6°C | 1.2°C | -30.6°C | 56 mm | 96% | 1.3 m/s | 1.5 |
| 1995 | -0.4°C | -5.8°C | -11.3°C | 5.0°C | -20.4°C | 27 mm | 88% | 1.1 m/s | 1.6 |
| 1994 | 0.1°C | -4.1°C | -8.4°C | 6.2°C | -17.5°C | 23 mm | 89% | 1.5 m/s | 1.4 |
| 1993 | -6.2°C | -11.5°C | -16.8°C | 0.7°C | -25.4°C | 28 mm | 97% | 1.3 m/s | 1.7 |
| 1992 | -1.4°C | -7.1°C | -12.8°C | 5.7°C | -22.6°C | 18 mm | 94% | 1.4 m/s | 1.5 |
| 1991 | -4.0°C | -9.5°C | -15.0°C | 2.1°C | -29.7°C | 24 mm | 93% | 1.5 m/s | 1.5 |
| 1990 | -1.2°C | -5.7°C | -10.2°C | 3.2°C | -18.0°C | 32 mm | 86% | 1.9 m/s | 1.4 |
| 1989 | -3.2°C | -8.7°C | -14.2°C | 2.8°C | -25.4°C | 43 mm | 94% | 1.8 m/s | 1.3 |
| 1988 | -3.4°C | -8.7°C | -14.0°C | 4.7°C | -21.8°C | 23 mm | 89% | 1.5 m/s | 1.5 |
| 1987 | -1.5°C | -6.6°C | -11.7°C | 5.1°C | -20.3°C | 12 mm | 86% | 1.4 m/s | 1.5 |
| 1986 | 0.3°C | -4.6°C | -9.6°C | 5.5°C | -20.6°C | 25 mm | 90% | 1.4 m/s | 1.4 |
| 1985 | -4.8°C | -10.5°C | -16.2°C | 0.9°C | -29.5°C | 12 mm | 95% | 1.3 m/s | 1.6 |
| 1984 | -1.9°C | -6.3°C | -10.7°C | 6.8°C | -25.8°C | 21 mm | 89% | 1.8 m/s | 1.4 |
| 1983 | 0.2°C | -4.7°C | -9.7°C | 2.9°C | -18.2°C | 16 mm | 90% | 1.5 m/s | — |
| 1982 | -5.6°C | -11.5°C | -17.3°C | 0.7°C | -31.2°C | 51 mm | 96% | 1.7 m/s | — |
| 1981 🔥 | 2.7°C | -2.6°C | -7.8°C | 8.1°C | -12.9°C | 15 mm | 83% | 1.1 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around -2.1°C with lows near -12.5°C (mean -7.3°C), based on 45 years of NASA POWER data.
January averages 30 mm of rainfall in Helena, one of the drier months. The wettest on record was 56 mm in 1996.
The hottest January reached 10.8°C in 2024. The coldest dipped to -33.2°C in 2024.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.3°C. Daytime highs moved from -1.9°C to -1.5°C and overnight lows from -12.3°C to -12.2°C over the same span.
January is one of the cooler months of the year in Helena and one of the drier months, so plan for around -2.1°C daytime highs and -12.5°C at night.
Yes — January is the coldest month of the year in Helena, averaging -7.3°C.
For January in Helena, pack warm layers and a jacket for chilly mornings, with typical highs of -2.1°C and lows of -12.5°C.
Relative humidity in January averages 91% — quite humid.
Average wind speed in January is 1.5 m/s. The windiest January on record averaged 1.9 m/s (1990).
The wettest January on record was 1996 with 56 mm. On average, January sees 30 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 Helena 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.
