January is one of the cooler months of the year in Idaho Falls, with average highs near -2.4°C and lows around -12.3°C (mean -7.3°C). It is about average for rainfall, averaging 51 mm of rainfall and 90% relative humidity across the period.
January is one of the cooler months of the year in Idaho Falls. Across 45 years of records, the warmest January in Idaho Falls was 1981 — when the month averaged -1.3°C — while the coldest was 2007 at -11.5°C. Typical January days reach -2.4°C with nights near -12.3°C. The long-term January temperature trend is broadly flat.
January is about average for rainfall in Idaho Falls, averaging 51 mm of rainfall. The wettest January on record was 2017 with 104 mm, while the driest was 1992 at 11 mm.
Relative humidity in Idaho Falls during January averages 90%. The most humid January was 1982 at 95%, and the least humid was 1981 at 72%.
January receives about 1.8 kWh/m²/day of solar energy in Idaho Falls. The sunniest January was 2007 at 2.3 kWh/m²/day, and the cloudiest were 1997, 2003 and 2020 at 1.5.
Average wind speed in Idaho Falls during January is 2.5 m/s. The windiest January was 1990 at 3.6 m/s, while the calmest was 1985 at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -7.8°C | -7.0°C | -7.4°C | -7.2°C | -7.4°C | +0.4°C |
| Avg High | -2.9°C | -2.1°C | -2.4°C | -2.2°C | -2.4°C | +0.5°C |
| Avg Low | -12.7°C | -12.0°C | -12.4°C | -12.2°C | -12.3°C | +0.4°C |
| Avg Rain | 37 mm | 54 mm | 51 mm | 61 mm | 51 mm | +14 mm |
January temperatures in Idaho Falls have fallen by about 0.4°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -33.4°C (1984) to a record high of 10.5°C (1981).
Rainfall in January is about average for rainfall, averaging 51 mm, with a wettest year of 104 mm.
A quieter season to visit Idaho Falls
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Idaho Falls. That said, January — with days averaging -2.4°C and nights around -12.3°C (mean -7.3°C) and moderate rainfall (51 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 | -3.9°C | -9.7°C | -15.4°C | 1.8°C | -29.6°C | 32 mm | 91% | 2 m/s | 2.2 |
| 2024 | -1.6°C | -6.0°C | -10.4°C | 5.4°C | -26.6°C | 64 mm | 89% | 2.4 m/s | 1.8 |
| 2023 | -3.4°C | -8.1°C | -12.9°C | 1.2°C | -32.3°C | 58 mm | 93% | 2.2 m/s | 1.9 |
| 2022 | -3.0°C | -8.1°C | -13.2°C | 1.4°C | -27.0°C | 30 mm | 91% | 2.2 m/s | 2 |
| 2021 | -1.3°C | -6.6°C | -11.9°C | 2.0°C | -18.0°C | 36 mm | 88% | 2.5 m/s | 1.8 |
| 2020 | -1.2°C | -5.7°C | -10.2°C | 1.7°C | -18.6°C | 85 mm | 93% | 3.3 m/s | 1.5 |
| 2019 | -2.0°C | -7.4°C | -12.8°C | 1.5°C | -22.2°C | 57 mm | 91% | 2.5 m/s | 1.8 |
| 2018 | -0.4°C | -5.2°C | -9.9°C | 3.0°C | -18.8°C | 66 mm | 88% | 2.6 m/s | 1.7 |
| 2017 🌧️ | -4.8°C | -10.4°C | -16.0°C | 1.4°C | -32.7°C | 104 mm | 92% | 2.5 m/s | 1.8 |
| 2016 | -2.1°C | -7.0°C | -11.9°C | 1.0°C | -22.9°C | 75 mm | 94% | 2.4 m/s | 1.7 |
| 2015 | -1.5°C | -5.9°C | -10.3°C | 2.0°C | -19.6°C | 50 mm | 93% | 1.9 m/s | 1.8 |
| 2014 | -0.5°C | -5.6°C | -10.8°C | 2.8°C | -17.1°C | 37 mm | 82% | 2.6 m/s | 2 |
| 2013 | -5.4°C | -10.3°C | -15.2°C | 1.1°C | -26.9°C | 41 mm | 92% | 2.1 m/s | 1.8 |
| 2012 | -0.1°C | -4.9°C | -9.6°C | 6.8°C | -19.2°C | 71 mm | 80% | 3.1 m/s | 1.9 |
| 2011 | -3.4°C | -8.3°C | -13.2°C | 1.4°C | -24.8°C | 52 mm | 94% | 2.4 m/s | 1.7 |
| 2010 | -1.5°C | -6.7°C | -12.0°C | 1.0°C | -27.3°C | 61 mm | 91% | 2.4 m/s | 1.7 |
| 2009 | -2.1°C | -7.1°C | -12.1°C | 1.5°C | -28.6°C | 54 mm | 90% | 2.5 m/s | 1.7 |
| 2008 | -4.4°C | -10.1°C | -15.8°C | 1.6°C | -24.4°C | 82 mm | 93% | 3.2 m/s | 1.8 |
| 2007 ❄️ | -5.4°C | -11.5°C | -17.5°C | 1.2°C | -32.6°C | 24 mm | 93% | 2.3 m/s | 2.3 |
| 2006 | -1.6°C | -6.3°C | -11.0°C | 1.7°C | -18.0°C | 85 mm | 93% | 3.2 m/s | 1.6 |
| 2005 | -1.5°C | -6.2°C | -10.8°C | 1.2°C | -20.3°C | 47 mm | 94% | 2 m/s | 1.8 |
| 2004 | -3.7°C | -8.3°C | -12.9°C | 1.2°C | -25.1°C | 47 mm | 94% | 2.5 m/s | 1.7 |
| 2003 | 2.0°C | -2.2°C | -6.5°C | 8.5°C | -13.5°C | 41 mm | 88% | 2.3 m/s | 1.5 |
| 2002 | -3.7°C | -8.3°C | -12.9°C | 1.5°C | -23.9°C | 45 mm | 93% | 2.6 m/s | 1.8 |
| 2001 | -2.3°C | -8.1°C | -13.8°C | 1.3°C | -19.3°C | 22 mm | 87% | 2 m/s | 2.1 |
| 2000 | -1.6°C | -5.9°C | -10.3°C | 2.9°C | -19.6°C | 63 mm | 91% | 2.6 m/s | 1.6 |
| 1999 | -0.3°C | -5.1°C | -9.9°C | 3.8°C | -18.2°C | 59 mm | 86% | 2.8 m/s | 1.6 |
| 1998 | -0.3°C | -4.4°C | -8.5°C | 3.2°C | -18.7°C | 80 mm | 91% | 3.3 m/s | 1.6 |
| 1997 | -3.9°C | -8.7°C | -13.6°C | 2.1°C | -26.8°C | 88 mm | 94% | 2.7 m/s | 1.5 |
| 1996 | -3.1°C | -8.5°C | -13.9°C | 1.5°C | -27.1°C | 78 mm | 91% | 3.2 m/s | 1.6 |
| 1995 | -1.8°C | -6.4°C | -11.1°C | 1.7°C | -25.0°C | 67 mm | 91% | 2.5 m/s | 1.8 |
| 1994 | -0.8°C | -5.6°C | -10.3°C | 3.2°C | -21.1°C | 27 mm | 88% | 2.6 m/s | 1.6 |
| 1993 | -3.6°C | -8.9°C | -14.2°C | 1.7°C | -22.6°C | 50 mm | 93% | 2.5 m/s | 1.9 |
| 1992 | -2.0°C | -7.2°C | -12.5°C | 3.4°C | -23.2°C | 11 mm | 88% | 2.2 m/s | 1.9 |
| 1991 | -4.9°C | -10.5°C | -16.2°C | 0.4°C | -28.5°C | 33 mm | 93% | 2.3 m/s | 1.8 |
| 1990 | -0.4°C | -5.1°C | -9.7°C | 6.1°C | -17.1°C | 50 mm | 84% | 3.6 m/s | 1.6 |
| 1989 | -4.7°C | -9.9°C | -15.1°C | 0.3°C | -23.6°C | 60 mm | 95% | 2.8 m/s | 1.6 |
| 1988 | -4.6°C | -10.1°C | -15.5°C | 1.4°C | -26.2°C | 50 mm | 92% | 2.6 m/s | 1.6 |
| 1987 | -2.8°C | -8.1°C | -13.4°C | 3.3°C | -26.5°C | 38 mm | 87% | 2.5 m/s | 1.7 |
| 1986 | -1.0°C | -5.6°C | -10.2°C | 2.0°C | -17.7°C | 46 mm | 90% | 2.4 m/s | 1.7 |
| 1985 | -5.4°C | -10.4°C | -15.3°C | 0.0°C | -31.2°C | 19 mm | 93% | 1.5 m/s | 2 |
| 1984 | -5.3°C | -10.3°C | -15.2°C | 0.6°C | -33.4°C | 19 mm | 94% | 1.9 m/s | 1.7 |
| 1983 | -0.5°C | -4.8°C | -9.1°C | 2.2°C | -18.3°C | 30 mm | 90% | 2.6 m/s | — |
| 1982 | -5.0°C | -9.7°C | -14.4°C | 2.2°C | -28.4°C | 53 mm | 95% | 3.5 m/s | — |
| 1981 🔥 | 3.3°C | -1.3°C | -6.0°C | 10.5°C | -11.0°C | 22 mm | 72% | 1.9 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around -2.4°C with lows near -12.3°C (mean -7.3°C), based on 45 years of NASA POWER data.
January averages 51 mm of rainfall in Idaho Falls, about average for rainfall. The wettest on record was 104 mm in 2017.
The hottest January reached 10.5°C in 1981. The coldest dipped to -33.4°C in 1984.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have fallen by about 0.4°C. Daytime highs moved from -2.6°C to -2.6°C and overnight lows from -12°C to -12.8°C over the same span.
January is one of the cooler months of the year in Idaho Falls and about average for rainfall, so plan for around -2.4°C daytime highs and -12.3°C at night.
Yes — January is the coldest month of the year in Idaho Falls, averaging -7.3°C.
For January in Idaho Falls, pack warm layers and a jacket for chilly mornings, with typical highs of -2.4°C and lows of -12.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 90% — quite humid.
Average wind speed in January is 2.5 m/s. The windiest January on record averaged 3.6 m/s (1990).
The wettest January on record was 2017 with 104 mm. On average, January sees 51 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 Idaho Falls 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.
