December is one of the cooler months of the year in Murrieta, with average highs near 18.3°C and lows around 9.7°C (mean 14°C). It is a relatively wet time of year, averaging 53 mm of rainfall and 61% relative humidity across the period.
December is one of the cooler months of the year in Murrieta. Across 45 years of records, the warmest Decembers in Murrieta were 2017 and 2025 — when the month averaged 17.4°C — while the coldest was 1987 at 11.1°C. Typical December days reach 18.3°C with nights near 9.7°C. The long-term trend is warming, about 0.4°C per decade.
December is a relatively wet time of year in Murrieta, averaging 53 mm of rainfall. The wettest December on record was 2010 with 233 mm, while the driest was 2017 at 0 mm.
Relative humidity in Murrieta during December averages 61%. The most humid December was 2010 at 72%, and the least humid was 2017 at 40%.
December receives about 2.9 kWh/m²/day of solar energy in Murrieta. The sunniest December was 2017 at 3.3 kWh/m²/day, and the cloudiest was 2010 at 2.5.
Average wind speed in Murrieta during December is 2.1 m/s. The windiest December was 1997 at 2.8 m/s, while the calmest was 2024 at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.5°C | 13.5°C | 13.8°C | 14.3°C | 15.3°C | +1.8°C |
| Avg High | 18.0°C | 18.1°C | 18.0°C | 18.4°C | 19.4°C | +1.4°C |
| Avg Low | 9.0°C | 9.0°C | 9.6°C | 10.3°C | 11.3°C | +2.3°C |
| Avg Rain | 54 mm | 40 mm | 45 mm | 71 mm | 54 mm | +0 mm |
December temperatures in Murrieta have risen by about 1.8°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -0.4°C (1990) to a record high of 27.9°C (2017).
Rainfall in December is a relatively wet time of year, averaging 53 mm, with a wettest year of 233 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.6°C per decade, narrowing the gap between day and night.
A quieter season to visit Murrieta
If your dates are flexible, the more temperate months of July and September tend to be the most comfortable for visiting Murrieta. That said, December — with days averaging 18.3°C and nights around 9.7°C (mean 14°C) and moderate rainfall (53 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 | 21.5°C | 17.4°C | 13.2°C | 27.3°C | 9.1°C | 64 mm | 64% | 1.8 m/s | — |
| 2024 | 20.2°C | 15.9°C | 11.6°C | 25.8°C | 9.0°C | 1 mm | 62% | 1.5 m/s | 2.9 |
| 2023 | 20.3°C | 16.2°C | 12.1°C | 25.3°C | 9.3°C | 34 mm | 66% | 1.7 m/s | 2.9 |
| 2022 | 17.4°C | 13.7°C | 10.1°C | 25.2°C | 6.2°C | 63 mm | 70% | 1.8 m/s | 2.7 |
| 2021 | 16.9°C | 13.4°C | 9.9°C | 26.5°C | 6.4°C | 136 mm | 71% | 2.3 m/s | 2.6 |
| 2020 | 20.0°C | 15.4°C | 10.8°C | 24.8°C | 6.8°C | 28 mm | 53% | 2 m/s | 3.1 |
| 2019 | 17.2°C | 13.7°C | 10.2°C | 22.0°C | 6.6°C | 106 mm | 69% | 2.3 m/s | 2.6 |
| 2018 | 18.6°C | 14.7°C | 10.8°C | 22.9°C | 5.4°C | 61 mm | 65% | 2 m/s | 3 |
| 2017 🔥 | 22.3°C | 17.4°C | 12.4°C | 27.9°C | 6.4°C | 0 mm | 40% | 1.8 m/s | 3.3 |
| 2016 | 17.8°C | 13.8°C | 9.9°C | 23.9°C | 5.5°C | 115 mm | 68% | 2.3 m/s | 2.7 |
| 2015 | 18.1°C | 13.8°C | 9.4°C | 26.4°C | 4.3°C | 30 mm | 56% | 2.3 m/s | 3.1 |
| 2014 | 18.6°C | 15.0°C | 11.4°C | 26.1°C | 5.0°C | 90 mm | 69% | 2 m/s | 2.7 |
| 2013 | 19.2°C | 14.5°C | 9.8°C | 25.2°C | 3.4°C | 10 mm | 54% | 1.8 m/s | 3.2 |
| 2012 | 16.8°C | 13.2°C | 9.5°C | 22.3°C | 4.4°C | 52 mm | 71% | 2.1 m/s | 2.7 |
| 2011 | 17.8°C | 13.3°C | 8.8°C | 24.0°C | 5.6°C | 15 mm | 55% | 1.8 m/s | 3.2 |
| 2010 🌧️ | 17.7°C | 14.0°C | 10.3°C | 27.0°C | 3.9°C | 233 mm | 72% | 2.3 m/s | 2.5 |
| 2009 | 16.9°C | 13.0°C | 9.2°C | 24.4°C | 4.4°C | 76 mm | 65% | 2.1 m/s | 2.8 |
| 2008 | 16.7°C | 12.8°C | 8.8°C | 25.3°C | 3.3°C | 95 mm | 67% | 2.2 m/s | 2.7 |
| 2007 | 16.7°C | 12.4°C | 8.2°C | 25.4°C | 3.1°C | 48 mm | 62% | 2.3 m/s | 3.1 |
| 2006 | 19.2°C | 14.4°C | 9.6°C | 25.0°C | 5.1°C | 21 mm | 52% | 2.1 m/s | 3.2 |
| 2005 | 19.4°C | 15.2°C | 10.9°C | 25.5°C | 7.3°C | 8 mm | 60% | 1.6 m/s | 2.8 |
| 2004 | 18.4°C | 14.1°C | 9.8°C | 26.1°C | 6.0°C | 98 mm | 64% | 2.3 m/s | 2.9 |
| 2003 | 17.9°C | 13.7°C | 9.5°C | 23.9°C | 4.6°C | 29 mm | 62% | 2.1 m/s | 2.8 |
| 2002 | 17.3°C | 13.4°C | 9.5°C | 21.4°C | 5.6°C | 50 mm | 69% | 2.1 m/s | 3 |
| 2001 | 17.0°C | 13.0°C | 9.0°C | 24.9°C | 5.7°C | 26 mm | 64% | 2 m/s | 2.9 |
| 2000 | 20.2°C | 15.8°C | 11.4°C | 24.6°C | 8.2°C | 1 mm | 54% | 1.7 m/s | 3 |
| 1999 | 19.9°C | 14.6°C | 9.4°C | 25.3°C | 5.6°C | 12 mm | 49% | 2 m/s | 3.2 |
| 1998 | 17.8°C | 13.2°C | 8.6°C | 25.9°C | 3.1°C | 20 mm | 55% | 2.3 m/s | 3 |
| 1997 | 18.0°C | 13.4°C | 8.8°C | 24.2°C | 3.6°C | 65 mm | 57% | 2.8 m/s | 3.1 |
| 1996 | 17.8°C | 13.9°C | 9.9°C | 21.6°C | 6.2°C | 72 mm | 68% | 2.6 m/s | 2.7 |
| 1995 | 19.3°C | 14.8°C | 10.3°C | 23.9°C | 7.0°C | 22 mm | 66% | 2.2 m/s | 2.8 |
| 1994 | 17.5°C | 13.2°C | 8.9°C | 23.3°C | 5.1°C | 23 mm | 63% | 2 m/s | 2.8 |
| 1993 | 18.7°C | 13.7°C | 8.7°C | 24.6°C | 4.7°C | 22 mm | 57% | 2.3 m/s | 3.1 |
| 1992 | 16.3°C | 12.1°C | 7.9°C | 21.4°C | 3.6°C | 103 mm | 63% | 2.6 m/s | 2.8 |
| 1991 | 17.9°C | 13.7°C | 9.6°C | 22.9°C | 4.5°C | 52 mm | 60% | 2.3 m/s | 2.8 |
| 1990 | 17.5°C | 12.4°C | 7.4°C | 26.2°C | -0.4°C | 8 mm | 46% | 2.6 m/s | 3.1 |
| 1989 | 20.9°C | 15.6°C | 10.2°C | 26.4°C | 5.9°C | 4 mm | 45% | 2 m/s | 3.1 |
| 1988 | 16.8°C | 12.5°C | 8.1°C | 26.1°C | 1.8°C | 76 mm | 59% | 2.5 m/s | 2.8 |
| 1987 ❄️ | 15.3°C | 11.1°C | 7.0°C | 22.8°C | 0.4°C | 64 mm | 63% | 2.6 m/s | 2.7 |
| 1986 | 19.2°C | 14.5°C | 9.9°C | 24.2°C | 5.9°C | 24 mm | 56% | 1.9 m/s | 2.8 |
| 1985 | 18.8°C | 14.1°C | 9.3°C | 24.7°C | 2.5°C | 23 mm | 60% | 1.9 m/s | 2.9 |
| 1984 | 16.3°C | 12.1°C | 8.0°C | 20.4°C | 3.9°C | 139 mm | 68% | 2.7 m/s | 2.7 |
| 1983 | 17.2°C | 13.3°C | 9.4°C | 21.8°C | 5.4°C | 84 mm | 70% | 2.2 m/s | — |
| 1982 | 17.3°C | 12.9°C | 8.5°C | 22.4°C | 2.1°C | 50 mm | 61% | 2.6 m/s | — |
| 1981 | 19.9°C | 15.2°C | 10.5°C | 24.7°C | 5.8°C | 22 mm | 60% | 1.8 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 18.3°C with lows near 9.7°C (mean 14°C), based on 45 years of NASA POWER data.
December averages 53 mm of rainfall in Murrieta, a relatively wet time of year. The wettest on record was 233 mm in 2010.
The hottest December reached 27.9°C in 2017. The coldest dipped to -0.4°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.8°C. Daytime highs moved from 17.9°C to 19.3°C and overnight lows from 9.1°C to 11.4°C over the same span.
December is one of the cooler months of the year in Murrieta and a relatively wet time of year, so plan for around 18.3°C daytime highs and 9.7°C at night.
Not quite — December is the 3rd coolest month in Murrieta, averaging 14°C.
For December in Murrieta, pack light layers you can adjust through the day, with typical highs of 18.3°C and lows of 9.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 61% — moderately humid.
Average wind speed in December is 2.1 m/s. The windiest December on record averaged 2.8 m/s (1997).
The wettest December on record was 2010 with 233 mm. On average, December sees 53 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 Murrieta 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.
