Custer County climate

Custer County Weather in December

NOAA 1991-2020 normals for Challis AP, 31.8 km from Custer County

Average highs run from 32°F on December 1 to 28°F on December 31, and lows from 15°F to 9°F. Normal precipitation for the month is 0.52 in over about 7 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 Custer County, in °F, with the record for each date.-40-20020406080151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

December at a glance

Average high
29°F
Average low
11°F
Precipitation
0.52 in
Record high
63°FDec 2, 2021
Record low
-23°FDec 18, 2016
Chance of a freeze
100%
Daylight
9 h 06 min to 8 h 55 min
Cloud cover
64%
Humidity
90%
Dew point
10°F
Wind
5.8 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation.

DateNormal highNormal lowRecord highRecord lowChance wet
Dec 132°F15°F62°F 2021-6°F 201522%
Dec 232°F14°F63°F 2021-3°F 201522%
Dec 332°F14°F51°F 2021-3°F 202222%
Dec 431°F14°F58°F 2021-6°F 200522%
Dec 531°F13°F52°F 2023-12°F 201322%
Dec 630°F13°F52°F 2023-11°F 200522%
Dec 730°F13°F48°F 2021-20°F 200522%
Dec 830°F12°F50°F 2015-22°F 200522%
Dec 930°F12°F55°F 2025-15°F 201322%
Dec 1029°F12°F57°F 2025-14°F 200922%
Dec 1129°F11°F60°F 2025-11°F 200922%
Dec 1229°F11°F59°F 2025-9°F 200522%
Dec 1329°F11°F51°F 2025-7°F 200522%
Dec 1428°F11°F50°F 2002-3°F 200522%
Dec 1528°F10°F50°F 2002-10°F 200523%
Dec 1628°F10°F55°F 2025-14°F 200523%
Dec 1728°F10°F53°F 2025-21°F 201623%
Dec 1828°F10°F50°F 2024-23°F 201623%
Dec 1928°F10°F47°F 2017-15°F 201623%
Dec 2028°F10°F47°F 2021-17°F 199823%
Dec 2128°F9°F46°F 2021-21°F 199823%
Dec 2228°F9°F45°F 2025-21°F 201623%
Dec 2328°F9°F46°F 2005-16°F 201623%
Dec 2428°F9°F48°F 2025-13°F 200123%
Dec 2528°F9°F46°F 2025-13°F 200123%
Dec 2628°F9°F44°F 2025-14°F 200123%
Dec 2728°F9°F47°F 2022-9°F 201523%
Dec 2828°F9°F47°F 2002-10°F 202023%
Dec 2928°F9°F53°F 2017-12°F 202023%
Dec 3028°F9°F50°F 2017-13°F 201423%
Dec 3128°F9°F42°F 2008-13°F 201423%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Custer County, in percent.05101520251102030
  • Chance of a wet day

Sunrise and sunset

Times for 2026, local time (MST).

December 1
sunrise 7:53 AM, sunset 4:59 PM
December 31
sunrise 8:13 AM, sunset 5:08 PM

Every day of December: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00004114 (Challis AP), public domain. Records: NOAA GHCN-Daily, station USW00004114, 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.