Altona climate

Altona Weather in December

NOAA 1991-2020 normals for Boulder, 15.9 km from Altona

Average highs run from 49°F on December 1 to 46°F on December 31, and lows from 23°F to 21°F. Normal precipitation for the month is 0.81 in over about 5 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 Altona, in °F, with the record for each date.-50-250255075100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

December at a glance

Average high
46°F
Average low
21°F
Precipitation
0.81 in
Snowfall
13.0 in
Record high
78°FDec 11, 1939
Record low
-32°FDec 23, 1924
Chance of a freeze
100%
Daylight
9 h 32 min to 9 h 22 min
Cloud cover
63%
Humidity
74%
Dew point
12°F
Wind
10.3 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 149°F23°F70°F 1917-16°F 192919%17%
Dec 248°F23°F76°F 2021-11°F 191919%17%
Dec 348°F23°F75°F 19410°F 191919%17%
Dec 448°F23°F75°F 1939-11°F 195518%17%
Dec 547°F22°F70°F 1980-17°F 190918%17%
Dec 647°F22°F77°F 1939-27°F 197218%17%
Dec 747°F22°F68°F 1923-20°F 197218%17%
Dec 847°F22°F70°F 1939-30°F 191918%17%
Dec 947°F21°F71°F 1933-25°F 191918%17%
Dec 1046°F21°F69°F 1957-22°F 197218%17%
Dec 1146°F21°F78°F 1939-29°F 193218%17%
Dec 1246°F21°F71°F 1921-19°F 193218%17%
Dec 1346°F21°F74°F 1921-20°F 192618%17%
Dec 1446°F21°F73°F 1924-22°F 192618%17%
Dec 1546°F21°F70°F 1939-13°F 197218%17%
Dec 1646°F21°F67°F 1942-11°F 197218%17%
Dec 1746°F21°F71°F 1939-13°F 196418%17%
Dec 1846°F20°F70°F 1980-19°F 192418%17%
Dec 1946°F20°F70°F 1941-20°F 192418%17%
Dec 2046°F20°F72°F 2025-14°F 191318%17%
Dec 2146°F20°F66°F 1931-18°F 199018%17%
Dec 2246°F20°F71°F 1933-31°F 199018%17%
Dec 2346°F20°F77°F 2025-32°F 192418%17%
Dec 2446°F20°F73°F 1955-23°F 198918%17%
Dec 2546°F21°F71°F 1955-14°F 194818%17%
Dec 2646°F21°F70°F 2025-15°F 192018%17%
Dec 2746°F21°F70°F 1947-14°F 198818%17%
Dec 2846°F21°F67°F 1980-16°F 198818%17%
Dec 2946°F21°F64°F 1933-20°F 198318%17%
Dec 3046°F21°F69°F 1917-24°F 192318%17%
Dec 3146°F21°F72°F 1980-22°F 191818%17%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Altona, in percent, and of at least 0.1 inch of snowfall.051015201102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (MST).

December 1
sunrise 7:04 AM, sunset 4:36 PM
December 31
sunrise 7:23 AM, sunset 4:45 PM

Every day of December: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00050848 (Boulder), public domain. Records: NOAA GHCN-Daily, station USC00055116, 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.