Gilroy weather in December: Gilroy, California: normal highs, lows, rain and records for December
Gilroy in December has a normal high of 60°F and a normal low of 37°F, a daily mean of 49°F, falling from 63°F on the 1st to 60°F by the 31st. Measurable precipitation falls on 9 days in a normal December, 3.69 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 16°C and low of 3°C, 94 mm of precipitation in December.
- NOAA stationGilroy
- Station IDUSC00043417
- Location37.00°N 121.56°W
- Elevation194 ft (59 m)
- From the center1 miles
- Population60,390
- Jan 61° 38°
- Feb 64° 40°
- Mar 68° 43°
- Apr 72° 45°
- May 77° 49°
- Jun 83° 52°
- Jul 87° 54°
- Aug 87° 54°
- Sep 85° 53°
- Oct 79° 48°
- Nov 68° 42°
- Dec 60° 37°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Gilroy in December?
The normal high is 60°F and the normal low 37°F, for a daily mean of 48.7°F. December is 6.3°F cooler than November and 0.7°F cooler than January. December is the 12th warmest month of the year in Gilroy and the 3rd wettest. Across the month the normal high falls 3°F, from 63°F on December 1 to 60°F on December 31. From one year to the next December's mean temperature typically moves about 2.1°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 47°F and 51°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 30%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 63°F | 38°F | 26% | 17% |
| December 8 | 61°F | 37°F | 28% | 19% |
| December 15 | 60°F | 37°F | 29% | 20% |
| December 22 | 60°F | 37°F | 30% | 21% |
| December 31 | 60°F | 37°F | 30% | 21% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 17)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 63°F | 38°F | 26% | 17% | 9 h 50 min |
| December 2 | 63°F | 38°F | 27% | 17% | 9 h 50 min |
| December 3 | 62°F | 38°F | 27% | 17% | 9 h 50 min |
| December 4 | 62°F | 38°F | 27% | 18% | 9 h 50 min |
| December 5 | 62°F | 38°F | 28% | 18% | 9 h 50 min |
| December 6 | 62°F | 38°F | 28% | 18% | 9 h 40 min |
| December 7 | 61°F | 37°F | 28% | 18% | 9 h 40 min |
| December 8 | 61°F | 37°F | 28% | 19% | 9 h 40 min |
| December 9 | 61°F | 37°F | 29% | 19% | 9 h 40 min |
| December 10 | 61°F | 37°F | 29% | 19% | 9 h 40 min |
| December 11 | 61°F | 37°F | 29% | 19% | 9 h 40 min |
| December 12 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 13 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 14 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 15 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 16 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 17 | 60°F | 37°F | 29% | 20% | 9 h 40 min |
| December 18 | 60°F | 37°F | 30% | 20% | 9 h 40 min |
| December 19 | 60°F | 37°F | 30% | 20% | 9 h 40 min |
| December 20 | 60°F | 37°F | 30% | 20% | 9 h 40 min |
| December 21 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 22 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 23 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 24 | 60°F | 37°F | 29% | 21% | 9 h 40 min |
| December 25 | 60°F | 37°F | 29% | 21% | 9 h 40 min |
| December 26 | 60°F | 37°F | 29% | 21% | 9 h 40 min |
| December 27 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 28 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 29 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 30 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
| December 31 | 60°F | 37°F | 30% | 21% | 9 h 40 min |
- Normal high
- 60°FDecember average
- Normal low
- 37°FDecember average
- Precipitation
- 3.69 inmonth total
- Days with precipitation
- 90.01 inch or more
- Nights at 32°F or colder
- 7
- Daylight
- 9 h 50 min to 9 h 40 minDecember 1 to December 31
- Days at 70°F or more
- 2
- Sunshine
- 74%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00043417; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Gilroy in December?
On a given December day the chance of 0.01 inch or more is 29% on average, highest around December 28 (30%). In all, 3.69 in falls on 9 days of a normal December, 1 of them with an inch or more.
In a normal December in Gilroy, 7 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00043417.
What are the records for December in Gilroy?
The warmest December temperature on this station's record (since 1957) is 80°F, on December 1, 2021; the coldest is 17°F, on December 24, 1990. The wettest December brought 11.65 in (2022).
The December mean against the 1991-2020 normal of 48.7°F: 2021 50.2°F (+1.5), 2022 49.7°F (+1.0). 2 of 2 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 50.2°F | +1.5°F | 8.04 in |
| 2022 | 49.7°F | +1.0°F | 11.65 in |
Source: records: ACIS, station USC00043417; recent months: ACIS, station USC00043417. Records and recent months use complete months only.
How does December in Gilroy compare across California?
Across the 219 places PlainClimate covers in California, December normal highs run from 38°F in Tahoma to 71°F in Anaheim; Gilroy's is 60°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.