December is one of the cooler months of the year in Waco, with average highs near 15.7°C and lows around 3.9°C (mean 9.8°C). It is about average for rainfall, averaging 73 mm of rainfall and 75% relative humidity across the period.
December is one of the cooler months of the year in Waco. Across 45 years of records, the warmest December in Waco was 2021 — when the month averaged 17.1°C — while the coldest was 1983 at 3.8°C. Typical December days reach 15.7°C with nights near 3.9°C. The long-term trend is warming, about 0.8°C per decade.
December is about average for rainfall in Waco, averaging 73 mm of rainfall. The wettest December on record was 1991 with 248 mm, while the driest was 2025 at 4 mm.
Relative humidity in Waco during December averages 75%. The most humid December was 1984 at 85%, and the least humid was 2005 at 60%.
December receives about 2.7 kWh/m²/day of solar energy in Waco. The sunniest Decembers were 1985, 2003 and 2023 at 3.2 kWh/m²/day, and the cloudiest were 1992 and 2014 at 2.
Average wind speed in Waco during December is 2.9 m/s. The windiest December was 2008 at 3.5 m/s, while the calmest was 1986 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.2°C | 9.8°C | 9.1°C | 10.2°C | 12.6°C | +4.4°C |
| Avg High | 13.9°C | 15.6°C | 15.2°C | 16.0°C | 18.9°C | +5°C |
| Avg Low | 2.5°C | 4.0°C | 3.0°C | 4.5°C | 6.4°C | +3.9°C |
| Avg Rain | 73 mm | 102 mm | 63 mm | 65 mm | 55 mm | -17 mm |
December temperatures in Waco have risen by about 4.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -16.7°C (1989) to a record high of 28.9°C (2025).
Rainfall in December is about average for rainfall, averaging 73 mm, with a wettest year of 248 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.9°C per decade while lows rose 0.7°C per decade, widening the gap between day and night.
A quieter season to visit Waco
If your dates are flexible, the more temperate months of October and May tend to be the most comfortable for visiting Waco. That said, December — with days averaging 15.7°C and nights around 3.9°C (mean 9.8°C) and moderate rainfall (73 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 | 18.7°C | 12.2°C | 5.7°C | 28.9°C | -2.7°C | 4 mm | 70% | 2.7 m/s | — |
| 2024 | 19.8°C | 13.6°C | 7.4°C | 27.2°C | 0.7°C | 75 mm | 72% | 2.6 m/s | 2.7 |
| 2023 | 18.3°C | 11.8°C | 5.3°C | 25.6°C | -0.7°C | 76 mm | 70% | 2.5 m/s | 3.2 |
| 2022 | 16.3°C | 10.9°C | 5.4°C | 26.2°C | -10.2°C | 34 mm | 75% | 2.7 m/s | 2.4 |
| 2021 🔥 | 23.0°C | 17.1°C | 11.2°C | 28.8°C | 0.2°C | 32 mm | 76% | 3 m/s | 2.8 |
| 2020 | 17.2°C | 10.2°C | 3.3°C | 25.4°C | -2.6°C | 111 mm | 69% | 2.8 m/s | 3 |
| 2019 | 17.8°C | 11.1°C | 4.5°C | 27.7°C | -2.1°C | 25 mm | 69% | 2.5 m/s | 3.1 |
| 2018 | 14.4°C | 9.5°C | 4.6°C | 21.6°C | -1.4°C | 130 mm | 80% | 3 m/s | 2.6 |
| 2017 | 15.6°C | 10.0°C | 4.3°C | 27.5°C | -4.0°C | 66 mm | 69% | 2.7 m/s | 2.3 |
| 2016 | 16.0°C | 10.7°C | 5.4°C | 26.5°C | -7.0°C | 45 mm | 74% | 3.1 m/s | 2.2 |
| 2015 | 17.7°C | 11.9°C | 6.0°C | 24.7°C | -1.0°C | 112 mm | 83% | 2.7 m/s | 2.9 |
| 2014 | 16.0°C | 11.1°C | 6.2°C | 25.4°C | -0.6°C | 32 mm | 79% | 2.8 m/s | 2 |
| 2013 | 12.8°C | 7.0°C | 1.3°C | 24.0°C | -6.9°C | 41 mm | 81% | 2.5 m/s | 2.7 |
| 2012 | 18.0°C | 11.6°C | 5.2°C | 28.2°C | -5.2°C | 40 mm | 66% | 3 m/s | 2.8 |
| 2011 | 14.5°C | 9.2°C | 3.9°C | 22.3°C | -6.0°C | 133 mm | 79% | 2.8 m/s | 2.1 |
| 2010 | 16.8°C | 10.1°C | 3.4°C | 28.8°C | -5.0°C | 25 mm | 65% | 3.3 m/s | 3.1 |
| 2009 | 11.7°C | 6.5°C | 1.3°C | 22.3°C | -5.5°C | 45 mm | 81% | 2.7 m/s | 2.5 |
| 2008 | 16.6°C | 9.8°C | 3.0°C | 26.1°C | -3.2°C | 18 mm | 64% | 3.5 m/s | 2.9 |
| 2007 | 17.0°C | 10.2°C | 3.5°C | 26.7°C | -5.1°C | 44 mm | 74% | 3 m/s | 2.9 |
| 2006 | 16.6°C | 10.4°C | 4.2°C | 25.6°C | -5.2°C | 81 mm | 73% | 2.9 m/s | 3 |
| 2005 | 15.9°C | 9.3°C | 2.7°C | 27.9°C | -5.6°C | 9 mm | 60% | 2.8 m/s | 3 |
| 2004 | 15.2°C | 9.2°C | 3.2°C | 22.7°C | -6.3°C | 27 mm | 78% | 2.7 m/s | 3.1 |
| 2003 | 16.9°C | 10.3°C | 3.6°C | 23.6°C | -2.3°C | 30 mm | 68% | 3.4 m/s | 3.2 |
| 2002 | 15.4°C | 9.6°C | 3.9°C | 22.2°C | -4.5°C | 160 mm | 81% | 3 m/s | 2.6 |
| 2001 | 16.2°C | 10.4°C | 4.5°C | 25.4°C | -4.2°C | 127 mm | 77% | 2.8 m/s | 2.7 |
| 2000 | 10.3°C | 4.9°C | -0.4°C | 21.9°C | -5.4°C | 90 mm | 81% | 2.9 m/s | 2.4 |
| 1999 | 17.6°C | 10.6°C | 3.6°C | 27.2°C | -2.7°C | 56 mm | 65% | 3.1 m/s | 3 |
| 1998 | 14.6°C | 9.4°C | 4.1°C | 25.8°C | -4.9°C | 97 mm | 83% | 3 m/s | 2.4 |
| 1997 | 14.2°C | 8.1°C | 2.0°C | 23.1°C | -4.9°C | 163 mm | 76% | 2.8 m/s | 2.9 |
| 1996 | 16.7°C | 10.1°C | 3.6°C | 25.6°C | -6.5°C | 63 mm | 78% | 3.1 m/s | 2.9 |
| 1995 | 16.6°C | 10.5°C | 4.3°C | 27.0°C | -6.3°C | 45 mm | 72% | 2.9 m/s | 2.8 |
| 1994 | 16.1°C | 10.6°C | 5.2°C | 25.0°C | -2.2°C | 151 mm | 84% | 2.3 m/s | 2.4 |
| 1993 | 14.8°C | 9.3°C | 3.7°C | 22.8°C | -4.5°C | 48 mm | 78% | 2.9 m/s | 2.5 |
| 1992 | 15.3°C | 10.0°C | 4.8°C | 24.1°C | -0.6°C | 109 mm | 83% | 2.8 m/s | 2 |
| 1991 🌧️ | 15.2°C | 10.5°C | 5.9°C | 23.4°C | -1.5°C | 248 mm | 84% | 2.9 m/s | 2.3 |
| 1990 | 15.0°C | 8.7°C | 2.5°C | 25.1°C | -8.3°C | 45 mm | 74% | 3 m/s | 2.7 |
| 1989 | 10.9°C | 4.4°C | -2.0°C | 22.4°C | -16.7°C | 11 mm | 61% | 3.1 m/s | 3.1 |
| 1988 | 16.6°C | 10.1°C | 3.7°C | 23.6°C | -2.8°C | 75 mm | 73% | 2.8 m/s | 2.5 |
| 1987 | 14.7°C | 8.9°C | 3.0°C | 23.2°C | -4.5°C | 102 mm | 78% | 3 m/s | 2.4 |
| 1986 | 12.3°C | 7.7°C | 3.1°C | 19.6°C | -2.0°C | 121 mm | 85% | 2.2 m/s | 2.3 |
| 1985 | 12.9°C | 6.8°C | 0.8°C | 22.3°C | -6.9°C | 67 mm | 80% | 2.8 m/s | 3.2 |
| 1984 | 18.3°C | 13.2°C | 8.2°C | 24.4°C | -4.1°C | 131 mm | 85% | 3 m/s | 2.2 |
| 1983 ❄️ | 9.3°C | 3.8°C | -1.7°C | 25.6°C | -13.4°C | 39 mm | 71% | 3.3 m/s | — |
| 1982 | 15.0°C | 9.4°C | 3.9°C | 26.2°C | -5.6°C | 97 mm | 79% | 3.2 m/s | — |
| 1981 | 15.3°C | 9.3°C | 3.2°C | 24.6°C | -5.7°C | 11 mm | 76% | 3.1 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 15.7°C with lows near 3.9°C (mean 9.8°C), based on 45 years of NASA POWER data.
December averages 73 mm of rainfall in Waco, about average for rainfall. The wettest on record was 248 mm in 1991.
The hottest December reached 28.9°C in 2025. The coldest dipped to -16.7°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 4.6°C. Daytime highs moved from 14.2°C to 19.2°C and overnight lows from 2.9°C to 7°C over the same span.
December is one of the cooler months of the year in Waco and about average for rainfall, so plan for around 15.7°C daytime highs and 3.9°C at night.
Not quite — December is the 2nd coolest month in Waco, averaging 9.8°C.
For December in Waco, pack warm layers and a jacket for chilly mornings, with typical highs of 15.7°C and lows of 3.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 75% — quite humid.
Average wind speed in December is 2.9 m/s. The windiest December on record averaged 3.5 m/s (2008).
The wettest December on record was 1991 with 248 mm. On average, December sees 73 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 Waco 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.
