Climate averages 1991–2020
Corona weather
in December.
A mild, moderately wet month: the coolest and the 9th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
December is a mild month in Corona: daytime highs average 18.0°C and nights cool to about 5.6°C. By daytime temperature it is the coolest month of the year.
Expect about 67 mm of rain on roughly 6 days, which makes December a moderately wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 57 min on an average December day.
The nearest other city in this atlas is Riverside (18 km away). In December its highs average 17.1°C, 1.0°C cooler than Corona, with 67 mm of rain.
Among the 498 cities listed in the United States, Corona ranks joint 61st of 498 for the warmest December highs and joint 245th of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Corona is 7.5°C warmer than that mean.
From December to January, average highs rise by 0.3°C to 18.3°C, and monthly rainfall rises from 67 mm to 96 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Corona climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 18.3°C5.8°C | 5.8°C | 96 | 6.6 | 10.210 h |
| February | 18.6°C6.6°C | 6.6°C | 111 | 7.4 | 10.911 h |
| March | 20.3°C8.5°C | 8.5°C | 68 | 6.8 | 12.012 h |
| April | 22.7°C10.4°C | 10.4°C | 32 | 4.6 | 13.013 h |
| May | 25.1°C13.1°C | 13.1°C | 15 | 2.6 | 13.914 h |
| June | 28.7°C15.6°C | 15.6°C | 3.4 | 0.5 | 14.414 h |
| July | 32.0°C18.5°C | 18.5°C | 2.2 | 0.5 | 14.214 h |
| August | 33.2°C19.3°C | 19.3°C | 1.1 | 0.3 | 13.413 h |
| September | 31.6°C17.8°C | 17.8°C | 5.5 | 1.2 | 12.412 h |
| October | 27.0°C13.7°C | 13.7°C | 22 | 3.1 | 11.411 h |
| November | 22.3°C9.1°C | 9.1°C | 30 | 3.5 | 10.410 h |
| December, selected | 18.0°C5.6°C | 5.6°C | 67 | 5.8 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Riverside in DecemberUnited States · 18 kmHigh 17.1°C · Low 4.5°C · 67 mm rain
- Chino in DecemberUnited States · 19 kmHigh 17.2°C · Low 5.2°C · 62 mm rain
- Chino Hills in DecemberUnited States · 22 kmHigh 16.9°C · Low 5.1°C · 62 mm rain
- Ontario in DecemberUnited States · 22 kmHigh 17.2°C · Low 6.1°C · 62 mm rain
- Rancho Cucamonga in DecemberUnited States · 26 kmHigh 16.9°C · Low 5.4°C · 67 mm rain
- Pomona in DecemberUnited States · 26 kmHigh 17.3°C · Low 6.1°C · 62 mm rain
- Fontana in DecemberUnited States · 27 kmHigh 16.3°C · Low 4.1°C · 67 mm rain
- Santa Ana, United States in DecemberUnited States · 31 kmHigh 17.4°C · Low 8.1°C · 55 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Corona) is explained once on the Corona year overview and on the Sources, method and limits page.
Riverside, Fontana and Rancho Cucamonga lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.