January is one of the cooler months of the year in Flagstaff, with average highs near 6.8°C and lows around -4.6°C (mean 1.1°C). It is about average for rainfall, averaging 47 mm of rainfall and 65% relative humidity across the period.
January is one of the cooler months of the year in Flagstaff. Across 45 years of records, the warmest January in Flagstaff was 2003 — when the month averaged 5.2°C — while the coldest was 1992 at -2.4°C. Typical January days reach 6.8°C with nights near -4.6°C. The long-term trend is warming, about 0.2°C per decade.
January is about average for rainfall in Flagstaff, averaging 47 mm of rainfall. The wettest January on record was 1993 with 220 mm, while the driest was 2011 at 1 mm.
Relative humidity in Flagstaff during January averages 65%. The most humid January was 1993 at 81%, and the least humid was 2025 at 44%.
January receives about 3.2 kWh/m²/day of solar energy in Flagstaff. The sunniest Januarys were 2011, 2014 and 2025 at 3.6 kWh/m²/day, and the cloudiest were 1997 and 2017 at 2.6.
Average wind speed in Flagstaff during January is 2.2 m/s. The windiest January was 2017 at 3.1 m/s, while the calmest were 2003 and 2015 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 0.5°C | 1.0°C | 1.5°C | 1.2°C | 1.4°C | +0.9°C |
| Avg High | 6.4°C | 6.5°C | 7.3°C | 6.9°C | 7.1°C | +0.7°C |
| Avg Low | -5.4°C | -4.5°C | -4.3°C | -4.6°C | -4.3°C | +1.1°C |
| Avg Rain | 45 mm | 65 mm | 39 mm | 48 mm | 35 mm | -10 mm |
January temperatures in Flagstaff have risen by about 0.6°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -22.4°C (2011) to a record high of 19.1°C (2003).
Rainfall in January is about average for rainfall, averaging 47 mm, with a wettest year of 220 mm.
A quieter season to visit Flagstaff
If your dates are flexible, the more temperate months of June and August tend to be the most comfortable for visiting Flagstaff. That said, January — with days averaging 6.8°C and nights around -4.6°C (mean 1.1°C) and moderate rainfall (47 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 | 7.0°C | 1.0°C | -5.0°C | 17.9°C | -12.4°C | 4 mm | 44% | 2.3 m/s | 3.6 |
| 2024 | 7.8°C | 2.0°C | -3.9°C | 15.3°C | -10.5°C | 30 mm | 65% | 2.2 m/s | 3 |
| 2023 | 5.0°C | 0.1°C | -4.7°C | 15.7°C | -11.6°C | 92 mm | 75% | 2.8 m/s | 3 |
| 2022 | 8.4°C | 2.3°C | -3.9°C | 13.0°C | -11.7°C | 7 mm | 53% | 2 m/s | 3.5 |
| 2021 | 6.3°C | 0.8°C | -4.7°C | 13.0°C | -14.4°C | 72 mm | 61% | 2 m/s | 3.1 |
| 2020 | 7.8°C | 2.1°C | -3.7°C | 14.2°C | -8.2°C | 6 mm | 63% | 2.2 m/s | 3.3 |
| 2019 | 6.5°C | 1.0°C | -4.4°C | 15.0°C | -17.2°C | 42 mm | 68% | 2.1 m/s | 3.1 |
| 2018 | 11.1°C | 4.4°C | -2.3°C | 18.5°C | -8.8°C | 26 mm | 48% | 2.1 m/s | 3.5 |
| 2017 | 5.1°C | 0.2°C | -4.6°C | 13.3°C | -16.0°C | 93 mm | 80% | 3.1 m/s | 2.6 |
| 2016 | 5.3°C | -0.1°C | -5.5°C | 13.7°C | -15.4°C | 58 mm | 72% | 2.1 m/s | 3.1 |
| 2015 | 8.4°C | 2.6°C | -3.1°C | 15.9°C | -12.1°C | 51 mm | 70% | 1.6 m/s | 3 |
| 2014 | 9.8°C | 3.5°C | -2.8°C | 15.0°C | -7.6°C | 2 mm | 47% | 1.9 m/s | 3.6 |
| 2013 | 4.3°C | -1.8°C | -7.8°C | 14.9°C | -17.8°C | 60 mm | 64% | 2.1 m/s | 3.3 |
| 2012 | 9.0°C | 2.8°C | -3.4°C | 14.9°C | -7.9°C | 6 mm | 50% | 2.2 m/s | 3.5 |
| 2011 | 5.5°C | -0.5°C | -6.5°C | 15.8°C | -22.4°C | 1 mm | 64% | 1.8 m/s | 3.6 |
| 2010 | 4.3°C | -0.6°C | -5.5°C | 12.2°C | -14.2°C | 137 mm | 70% | 2 m/s | 3 |
| 2009 | 7.3°C | 1.8°C | -3.7°C | 12.3°C | -8.7°C | 21 mm | 64% | 2 m/s | 3.4 |
| 2008 | 3.8°C | -1.5°C | -6.8°C | 10.7°C | -13.9°C | 108 mm | 72% | 2.7 m/s | 3.1 |
| 2007 | 4.4°C | -1.3°C | -7.0°C | 11.5°C | -15.4°C | 35 mm | 65% | 2.5 m/s | 3.2 |
| 2006 | 8.3°C | 2.2°C | -4.0°C | 14.2°C | -9.5°C | 5 mm | 48% | 2.3 m/s | 3.5 |
| 2005 | 8.0°C | 2.6°C | -2.7°C | 14.7°C | -11.7°C | 117 mm | 79% | 2.4 m/s | 2.8 |
| 2004 | 6.8°C | 1.4°C | -4.0°C | 11.7°C | -8.8°C | 28 mm | 66% | 1.9 m/s | 3 |
| 2003 🔥 | 12.0°C | 5.2°C | -1.6°C | 19.1°C | -6.7°C | 7 mm | 56% | 1.6 m/s | 3.4 |
| 2002 | 7.1°C | 1.3°C | -4.4°C | 16.2°C | -11.8°C | 4 mm | 52% | 2.4 m/s | 3.3 |
| 2001 | 5.3°C | -0.1°C | -5.5°C | 12.2°C | -14.4°C | 49 mm | 68% | 1.9 m/s | 2.9 |
| 2000 | 9.5°C | 3.1°C | -3.4°C | 17.9°C | -11.6°C | 17 mm | 54% | 2.2 m/s | 3.1 |
| 1999 | 8.7°C | 2.8°C | -3.2°C | 14.9°C | -8.8°C | 8 mm | 52% | 2.5 m/s | 3.4 |
| 1998 | 8.6°C | 3.0°C | -2.7°C | 14.5°C | -8.2°C | 28 mm | 64% | 2 m/s | 3.1 |
| 1997 | 4.9°C | -0.4°C | -5.6°C | 15.1°C | -16.2°C | 117 mm | 81% | 2.6 m/s | 2.6 |
| 1996 | 8.1°C | 2.0°C | -4.0°C | 16.0°C | -8.7°C | 7 mm | 50% | 2.7 m/s | 3 |
| 1995 | 5.4°C | 0.7°C | -4.1°C | 13.9°C | -9.3°C | 98 mm | 77% | 2.4 m/s | 2.7 |
| 1994 | 7.1°C | 1.4°C | -4.3°C | 14.7°C | -11.5°C | 13 mm | 57% | 1.9 m/s | 3.3 |
| 1993 🌧️ | 6.1°C | 1.5°C | -3.1°C | 11.7°C | -11.5°C | 220 mm | 81% | 2.6 m/s | 2.9 |
| 1992 ❄️ | 3.2°C | -2.4°C | -8.0°C | 10.9°C | -15.4°C | 83 mm | 78% | 1.9 m/s | 3.2 |
| 1991 | 6.2°C | 0.7°C | -4.8°C | 9.7°C | -10.9°C | 34 mm | 65% | 1.8 m/s | 3.2 |
| 1990 | 6.5°C | 0.7°C | -5.0°C | 16.6°C | -14.6°C | 40 mm | 60% | 2.2 m/s | 3.1 |
| 1989 | 5.2°C | -0.7°C | -6.6°C | 12.1°C | -14.3°C | 55 mm | 68% | 2.1 m/s | 3.2 |
| 1988 | 4.5°C | -1.3°C | -7.1°C | 12.6°C | -20.7°C | 62 mm | 73% | 2.3 m/s | 3 |
| 1987 | 4.8°C | -0.8°C | -6.3°C | 14.2°C | -15.3°C | 68 mm | 69% | 2.2 m/s | 2.9 |
| 1986 | 10.8°C | 4.2°C | -2.5°C | 18.0°C | -6.5°C | 6 mm | 63% | 1.8 m/s | 3.2 |
| 1985 | 4.9°C | -0.5°C | -6.0°C | 12.8°C | -15.7°C | 65 mm | 75% | 2.1 m/s | 2.8 |
| 1984 | 5.9°C | -0.1°C | -6.0°C | 12.2°C | -14.0°C | 12 mm | 69% | 1.8 m/s | 3.3 |
| 1983 | 6.5°C | 0.9°C | -4.7°C | 11.9°C | -12.4°C | 42 mm | 72% | 1.8 m/s | — |
| 1982 | 4.8°C | -0.8°C | -6.4°C | 14.3°C | -17.5°C | 80 mm | 71% | 2.9 m/s | — |
| 1981 | 9.8°C | 3.5°C | -2.7°C | 15.8°C | -6.4°C | 21 mm | 58% | 1.7 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 6.8°C with lows near -4.6°C (mean 1.1°C), based on 45 years of NASA POWER data.
January averages 47 mm of rainfall in Flagstaff, about average for rainfall. The wettest on record was 220 mm in 1993.
The hottest January reached 19.1°C in 2003. The coldest dipped to -22.4°C in 2011.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.6°C. Daytime highs moved from 6.4°C to 6.9°C and overnight lows from -5.2°C to -4.4°C over the same span.
January is one of the cooler months of the year in Flagstaff and about average for rainfall, so plan for around 6.8°C daytime highs and -4.6°C at night.
Yes — January is the coldest month of the year in Flagstaff, averaging 1.1°C.
For January in Flagstaff, pack warm layers and a jacket for chilly mornings, with typical highs of 6.8°C and lows of -4.6°C.
Relative humidity in January averages 65% — moderately humid.
Average wind speed in January is 2.2 m/s. The windiest January on record averaged 3.1 m/s (2017).
The wettest January on record was 1993 with 220 mm. On average, January sees 47 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 Flagstaff 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.
