December is one of the cooler months of the year in Tucson, with average highs near 17.8°C and lows around 4.2°C (mean 11°C). It is about average for rainfall, averaging 33 mm of rainfall and 48% relative humidity across the period.
December is one of the cooler months of the year in Tucson. Across 45 years of records, the warmest December in Tucson was 2025 — when the month averaged 16.2°C — while the coldest was 1997 at 8.1°C. Typical December days reach 17.8°C with nights near 4.2°C. The long-term trend is warming, about 0.7°C per decade.
December is about average for rainfall in Tucson, averaging 33 mm of rainfall. The wettest December on record was 1984 with 111 mm, while the driest was 2024 at 0 mm.
Relative humidity in Tucson during December averages 48%. The most humid December was 1984 at 69%, and the least humid was 2024 at 26%.
December receives about 3.2 kWh/m²/day of solar energy in Tucson. The sunniest Decembers were 2020 and 2024 at 3.6 kWh/m²/day, and the cloudiest were 1984 and 1991 at 2.9.
Average wind speed in Tucson during December is 2.5 m/s. The windiest Decembers were 1988, 1990 and 2004, among others at 3 m/s, while the calmest was 2005 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.4°C | 10.2°C | 10.4°C | 11.5°C | 13.5°C | +3.1°C |
| Avg High | 17.1°C | 17.0°C | 17.4°C | 18.0°C | 20.5°C | +3.4°C |
| Avg Low | 3.7°C | 3.4°C | 3.5°C | 4.9°C | 6.5°C | +2.8°C |
| Avg Rain | 40 mm | 44 mm | 20 mm | 33 mm | 24 mm | -16 mm |
December temperatures in Tucson have risen by about 3.1°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -6.5°C (1990) to a record high of 28.6°C (2025).
Rainfall in December is about average for rainfall, averaging 33 mm, with a wettest year of 111 mm.
A quieter season to visit Tucson
If your dates are flexible, the more temperate months of October and May tend to be the most comfortable for visiting Tucson. That said, December — with days averaging 17.8°C and nights around 4.2°C (mean 11°C) and moderate rainfall (33 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 🔥 | 23.3°C | 16.2°C | 9.0°C | 28.6°C | 3.8°C | 6 mm | 43% | 2.1 m/s | — |
| 2024 | 23.3°C | 15.6°C | 7.8°C | 28.0°C | 2.2°C | 0 mm | 26% | 2.2 m/s | 3.6 |
| 2023 | 20.4°C | 13.5°C | 6.5°C | 27.2°C | 3.1°C | 38 mm | 38% | 2.4 m/s | 3.3 |
| 2022 | 17.8°C | 11.4°C | 5.1°C | 24.5°C | -1.6°C | 47 mm | 54% | 2.2 m/s | 3 |
| 2021 | 19.5°C | 13.3°C | 7.1°C | 26.6°C | 0.3°C | 43 mm | 52% | 2.5 m/s | 3 |
| 2020 | 18.5°C | 11.1°C | 3.6°C | 24.9°C | -0.6°C | 8 mm | 32% | 2.7 m/s | 3.6 |
| 2019 | 17.1°C | 10.8°C | 4.6°C | 23.8°C | -2.6°C | 57 mm | 57% | 2.6 m/s | 3 |
| 2018 | 17.7°C | 11.2°C | 4.8°C | 25.0°C | -2.9°C | 31 mm | 52% | 2.3 m/s | 3 |
| 2017 | 20.3°C | 13.9°C | 7.4°C | 26.8°C | -1.3°C | 11 mm | 34% | 2.3 m/s | 3.1 |
| 2016 | 19.4°C | 13.0°C | 6.6°C | 27.1°C | -1.0°C | 38 mm | 50% | 2.6 m/s | 3.2 |
| 2015 | 16.9°C | 9.9°C | 2.9°C | 25.5°C | -3.4°C | 16 mm | 46% | 2.4 m/s | 3.3 |
| 2014 | 17.5°C | 11.4°C | 5.3°C | 23.7°C | -2.3°C | 45 mm | 56% | 2.1 m/s | 3.1 |
| 2013 | 17.8°C | 10.8°C | 3.9°C | 27.1°C | -0.9°C | 17 mm | 47% | 2.8 m/s | 3.4 |
| 2012 | 17.7°C | 11.4°C | 5.1°C | 28.0°C | -1.3°C | 34 mm | 45% | 2.4 m/s | 3.4 |
| 2011 | 15.3°C | 8.8°C | 2.2°C | 25.9°C | -4.2°C | 53 mm | 54% | 2.4 m/s | 3 |
| 2010 | 20.4°C | 13.4°C | 6.3°C | 27.9°C | -4.0°C | 24 mm | 42% | 2.5 m/s | 3.1 |
| 2009 | 15.7°C | 9.2°C | 2.7°C | 22.5°C | -0.8°C | 14 mm | 49% | 2.5 m/s | 3.2 |
| 2008 | 17.5°C | 10.8°C | 4.2°C | 24.9°C | -3.4°C | 28 mm | 51% | 2.8 m/s | 3.1 |
| 2007 | 15.2°C | 8.6°C | 2.0°C | 26.7°C | -3.3°C | 39 mm | 52% | 2.6 m/s | 3.4 |
| 2006 | 17.4°C | 10.1°C | 2.8°C | 24.7°C | -1.7°C | 12 mm | 44% | 2.7 m/s | 3.4 |
| 2005 | 20.1°C | 12.9°C | 5.7°C | 25.7°C | -0.6°C | 2 mm | 27% | 1.8 m/s | 3.5 |
| 2004 | 17.8°C | 10.6°C | 3.5°C | 26.3°C | -3.4°C | 35 mm | 50% | 3 m/s | 3.3 |
| 2003 | 18.4°C | 11.0°C | 3.6°C | 27.0°C | -5.5°C | 13 mm | 41% | 2.7 m/s | 3.5 |
| 2002 | 16.3°C | 9.8°C | 3.4°C | 23.2°C | -1.7°C | 28 mm | 51% | 2.3 m/s | 3.2 |
| 2001 | 16.7°C | 9.5°C | 2.2°C | 24.8°C | -2.7°C | 27 mm | 46% | 2.5 m/s | 3.4 |
| 2000 | 19.2°C | 11.9°C | 4.6°C | 23.7°C | -0.2°C | 2 mm | 47% | 2.3 m/s | 3.5 |
| 1999 | 18.0°C | 10.7°C | 3.4°C | 25.9°C | -0.8°C | 1 mm | 29% | 2.8 m/s | 3.5 |
| 1998 | 17.4°C | 10.1°C | 2.8°C | 24.0°C | -3.7°C | 13 mm | 48% | 2.7 m/s | 3.5 |
| 1997 ❄️ | 14.5°C | 8.1°C | 1.6°C | 22.0°C | -4.1°C | 75 mm | 57% | 2.8 m/s | 3.2 |
| 1996 | 19.3°C | 11.7°C | 4.1°C | 27.1°C | -3.7°C | 0 mm | 39% | 2.5 m/s | 3.5 |
| 1995 | 18.9°C | 12.0°C | 5.1°C | 25.1°C | -0.5°C | 10 mm | 42% | 2.1 m/s | 3.3 |
| 1994 | 16.5°C | 10.3°C | 4.0°C | 23.0°C | -1.0°C | 105 mm | 62% | 2.4 m/s | 3 |
| 1993 | 17.8°C | 10.7°C | 3.5°C | 24.6°C | -3.6°C | 8 mm | 47% | 2.6 m/s | 3.4 |
| 1992 | 15.5°C | 9.2°C | 2.9°C | 21.8°C | -2.7°C | 104 mm | 62% | 2.5 m/s | 3 |
| 1991 | 16.3°C | 10.3°C | 4.3°C | 22.2°C | -2.7°C | 57 mm | 64% | 2.8 m/s | 2.9 |
| 1990 | 16.0°C | 9.3°C | 2.6°C | 24.2°C | -6.5°C | 66 mm | 53% | 3 m/s | 3 |
| 1989 | 17.9°C | 10.8°C | 3.7°C | 24.4°C | -3.1°C | 14 mm | 41% | 2.8 m/s | 3.5 |
| 1988 | 15.9°C | 9.2°C | 2.6°C | 23.4°C | -3.5°C | 6 mm | 50% | 3 m/s | 3.3 |
| 1987 | 15.3°C | 8.7°C | 2.1°C | 25.2°C | -5.9°C | 59 mm | 52% | 2.4 m/s | 3 |
| 1986 | 16.9°C | 10.2°C | 3.5°C | 24.4°C | -2.8°C | 47 mm | 58% | 2.3 m/s | 3.1 |
| 1985 | 18.5°C | 11.2°C | 3.8°C | 23.2°C | -3.3°C | 12 mm | 47% | 2.4 m/s | 3.5 |
| 1984 🌧️ | 15.6°C | 9.9°C | 4.3°C | 23.2°C | -3.2°C | 111 mm | 69% | 2.6 m/s | 2.9 |
| 1983 | 16.8°C | 10.5°C | 4.2°C | 23.6°C | -1.9°C | 36 mm | 68% | 2.6 m/s | — |
| 1982 | 16.0°C | 9.5°C | 3.1°C | 24.9°C | -2.9°C | 70 mm | 58% | 3 m/s | — |
| 1981 | 20.8°C | 13.2°C | 5.7°C | 27.5°C | -2.1°C | 2 mm | 42% | 2.2 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 17.8°C with lows near 4.2°C (mean 11°C), based on 45 years of NASA POWER data.
December averages 33 mm of rainfall in Tucson, about average for rainfall. The wettest on record was 111 mm in 1984.
The hottest December reached 28.6°C in 2025. The coldest dipped to -6.5°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 3.1°C. Daytime highs moved from 17.5°C to 20.9°C and overnight lows from 4.2°C to 7.1°C over the same span.
December is one of the cooler months of the year in Tucson and about average for rainfall, so plan for around 17.8°C daytime highs and 4.2°C at night.
Not quite — December is the 2nd coolest month in Tucson, averaging 11°C.
For December in Tucson, pack warm layers and a jacket for chilly mornings, with typical highs of 17.8°C and lows of 4.2°C.
Relative humidity in December averages 48% — relatively dry.
Average wind speed in December is 2.5 m/s. The windiest December on record averaged 3 m/s (1982).
The wettest December on record was 1984 with 111 mm. On average, December sees 33 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 Tucson behaves each December, 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 December specifically, along with year-by-year records and how the month has changed over the decades.
