Blackhawk climate

Blackhawk Weather in December

NOAA 1991-2020 normals for Mt Diablo Junction, 6.8 km from Blackhawk

Average highs run from 55°F on December 1 to 53°F on December 31, and lows from 43°F to 41°F. Normal precipitation for the month is 5.08 in over about 11 wet days.

December day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Blackhawk, in °F, with the record for each date.020406080151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

December at a glance

Average high
53°F
Average low
41°F
Precipitation
5.08 in
Record high
79°FDec 12, 1958
Record low
18°FDec 9, 1972
Chance of a freeze
49%
Daylight
9 h 44 min to 9 h 36 min
Cloud cover
60%
Humidity
79%
Dew point
40°F
Wind
6.9 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Dec 155°F43°F75°F 191027°F 196931%0%
Dec 255°F42°F75°F 191026°F 190631%0%
Dec 355°F42°F76°F 195827°F 193632%0%
Dec 454°F42°F74°F 195823°F 190932%0%
Dec 554°F42°F77°F 195821°F 197232%0%
Dec 654°F42°F75°F 195826°F 190433%0%
Dec 754°F42°F73°F 191726°F 191633%0%
Dec 854°F42°F74°F 202421°F 197833%0%
Dec 954°F41°F73°F 191718°F 197233%0%
Dec 1053°F41°F72°F 191120°F 197233%0%
Dec 1153°F41°F72°F 195820°F 193234%0%
Dec 1253°F41°F79°F 195820°F 197234%0%
Dec 1353°F41°F73°F 195824°F 194534%0%
Dec 1453°F41°F75°F 195819°F 197234%0%
Dec 1553°F41°F68°F 194121°F 193235%0%
Dec 1653°F41°F72°F 195825°F 196735%0%
Dec 1753°F41°F75°F 191722°F 196535%0%
Dec 1853°F41°F76°F 195823°F 196535%0%
Dec 1953°F41°F70°F 195823°F 196535%0%
Dec 2053°F41°F69°F 191523°F 197835%0%
Dec 2153°F41°F69°F 191520°F 196835%0%
Dec 2253°F41°F71°F 199918°F 199035%0%
Dec 2353°F41°F70°F 191719°F 199035%0%
Dec 2453°F41°F78°F 194620°F 196335%0%
Dec 2553°F41°F67°F 190721°F 196335%0%
Dec 2653°F41°F70°F 196722°F 192435%0%
Dec 2753°F41°F78°F 191722°F 196236%0%
Dec 2853°F41°F73°F 191723°F 196236%0%
Dec 2953°F41°F73°F 196724°F 196236%0%
Dec 3053°F41°F71°F 194520°F 197836%0%
Dec 3153°F41°F69°F 199620°F 197836%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Blackhawk, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PST).

December 1
sunrise 7:05 AM, sunset 4:49 PM
December 31
sunrise 7:23 AM, sunset 4:59 PM

Every day of December: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00045915 (Mt Diablo Junction), public domain. Records: NOAA GHCN-Daily, station USC00044997, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.