Twin Falls weather in December: Twin Falls, Idaho: normal highs, lows, rain and records for December
Twin Falls in December has a normal high of 37°F and a normal low of 20°F, a daily mean of 29°F, falling from 40°F on the 1st to 36°F by the 31st. Measurable precipitation falls on 10 days in a normal December, 1.23 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 3°C and low of −7°C, 31 mm of precipitation in December.
- NOAA stationTwin Falls Sun Valley Regional Airport
- Station IDUSW00094178
- Location42.48°N 114.49°W
- Elevation4,151 ft (1,265 m)
- Population55,589
- Jan 37° 21°
- Feb 42° 24°
- Mar 52° 30°
- Apr 59° 34°
- May 69° 42°
- Jun 78° 49°
- Jul 88° 58°
- Aug 87° 56°
- Sep 76° 47°
- Oct 62° 36°
- Nov 47° 26°
- Dec 37° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Twin Falls in December?
The normal high is 37°F and the normal low 20°F, for a daily mean of 28.5°F. December is 8.1°F cooler than November and 0.6°F cooler than January. December is the 12th warmest month of the year in Twin Falls and the 2nd wettest. Across the month the normal high falls 4°F, from 40°F on December 1 to 36°F on December 31. From one year to the next December's mean temperature typically moves about 2.9°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 26°F and 31°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 | 40°F | 22°F | 27% | 11% |
| December 8 | 38°F | 20°F | 28% | 11% |
| December 15 | 36°F | 20°F | 29% | 12% |
| December 22 | 36°F | 20°F | 30% | 12% |
| December 31 | 36°F | 20°F | 28% | 11% |
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 | 40°F | 22°F | 27% | 11% | 9 h 20 min |
| December 2 | 39°F | 22°F | 27% | 11% | 9 h 20 min |
| December 3 | 39°F | 21°F | 27% | 11% | 9 h 20 min |
| December 4 | 39°F | 21°F | 27% | 11% | 9 h 20 min |
| December 5 | 38°F | 21°F | 28% | 11% | 9 h 10 min |
| December 6 | 38°F | 21°F | 28% | 11% | 9 h 10 min |
| December 7 | 38°F | 21°F | 28% | 11% | 9 h 10 min |
| December 8 | 38°F | 20°F | 28% | 11% | 9 h 10 min |
| December 9 | 37°F | 20°F | 28% | 11% | 9 h 10 min |
| December 10 | 37°F | 20°F | 29% | 11% | 9 h 10 min |
| December 11 | 37°F | 20°F | 29% | 11% | 9 h 10 min |
| December 12 | 37°F | 20°F | 29% | 12% | 9 h 10 min |
| December 13 | 37°F | 20°F | 29% | 12% | 9 h 10 min |
| December 14 | 37°F | 20°F | 29% | 12% | 9 h 10 min |
| December 15 | 36°F | 20°F | 29% | 12% | 9 h 10 min |
| December 16 | 36°F | 20°F | 29% | 12% | 9 h 10 min |
| December 17 | 36°F | 20°F | 29% | 12% | 9 h |
| December 18 | 36°F | 20°F | 29% | 12% | 9 h |
| December 19 | 36°F | 20°F | 30% | 12% | 9 h |
| December 20 | 36°F | 20°F | 30% | 12% | 9 h |
| December 21 | 36°F | 20°F | 30% | 12% | 9 h |
| December 22 | 36°F | 20°F | 30% | 12% | 9 h |
| December 23 | 36°F | 20°F | 30% | 12% | 9 h |
| December 24 | 36°F | 20°F | 29% | 12% | 9 h |
| December 25 | 36°F | 20°F | 29% | 12% | 9 h |
| December 26 | 36°F | 20°F | 29% | 12% | 9 h |
| December 27 | 36°F | 20°F | 29% | 11% | 9 h |
| December 28 | 36°F | 20°F | 29% | 11% | 9 h |
| December 29 | 36°F | 20°F | 29% | 11% | 9 h 10 min |
| December 30 | 36°F | 20°F | 29% | 11% | 9 h 10 min |
| December 31 | 36°F | 20°F | 28% | 11% | 9 h 10 min |
- Normal high
- 37°FDecember average
- Normal low
- 20°FDecember average
- Precipitation
- 1.23 inmonth total
- Days with precipitation
- 100.01 inch or more
- Nights at 32°F or colder
- 27
- Daylight
- 9 h 20 min to 9 h 10 minDecember 1 to December 31
- Sunshine
- 62%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00094178; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Twin Falls in December?
On a given December day the chance of 0.01 inch or more is 29% on average, highest around December 19 (30%). In all, 1.23 in falls on 10 days of a normal December.
In a normal December in Twin Falls, 27 nights fall to freezing and 9 days stay below freezing all day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00094178.
What are the records for December in Twin Falls?
The warmest December temperature on this station's record (since 1997) is 63°F, on December 11, 2025; the coldest is −12°F, on December 31, 2015. The wettest December brought 3.06 in (2005).
The December mean against the 1991-2020 normal of 28.5°F: 2021 33.0°F (+4.5), 2022 27.9°F (−0.6), 2023 32.7°F (+4.2), 2024 34.7°F (+6.2), 2025 40.8°F (+12.3). 4 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 33.0°F | +4.5°F | 1.07 in |
| 2022 | 27.9°F | −0.6°F | 0.78 in |
| 2023 | 32.7°F | +4.2°F | 0.79 in |
| 2024 | 34.7°F | +6.2°F | 2.01 in |
| 2025 | 40.8°F | +12.3°F | 0.98 in |
Source: records: ACIS, station USW00094178; recent months: ACIS, station USW00094178. Records and recent months use complete months only.
How does December in Twin Falls compare across Idaho?
Across the 85 places PlainClimate covers in Idaho, December normal highs run from 26°F in Island Park to 44°F in Glenns Ferry; Twin Falls's is 37°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.