Twin Falls weather in December

In December, Twin Falls sees average daytime highs of 38°F and overnight lows near 24°F, with 1.6 in of precipitation across 8.8 wet days and about 8.9 hours of daylight. It is the 12th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 41°F in the first days to 37°F by the end. The sky is clear or mostly clear about 28% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 06 min at the start of December to 8 h 54 min by month's end. Set against the rest of the year, December is Twin Falls's 11th-clearest and 7th-windiest month. For the whole year in context, see Twin Falls's year-round climate.

Daytime high
38°
12th warmest
Overnight low
24°
2nd coldest
Precipitation
1.6 in
8.8 wet days
Daylight
8 h 54 min
8:07 AM – 5:01 PM
Cloud cover
62%
11th clearest
Wind
7 mph
7th windiest
Solar energy
1.85 kWh/m²
Travel score
0.0
out of 10

Twin Falls is city in and county seat of Twin Falls County, Idaho, United States.

Density
1,009/km²
people per km²
Founded
1904

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 41°F in the first days to 37°F by the end.

A typical December day in Twin Falls reaches about 38°F in the afternoon and slips back to 24°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 28°F and 48°F. Set against its neighbours, December runs about 10°F cooler than November and on par with January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14126
24125
34125
44025
54025
64025
74024
83924
93924
103924
113924
123824
133824
143824
153824
163824
173823
183823
193723
203723
213723
223723
233723
243723
253723
263722
273722
283722
293722
303722
313722

How December really feels in Twin Falls

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
6 feel bitter (≤ 14°F)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Twin Falls weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 24°1.596.29.20.0
Feb44° / 27°1.17.44.210.30.8
Mar54° / 33°1.48.82.711.63.3
Apr61° / 38°1.48.21.413.15.3
May71° / 46°1.57.50.114.47.0
Jun81° / 53°0.84.2015.17.3
Jul91° / 60°0.21.7014.84.6
Aug89° / 59°0.31.9013.75.2
Sep78° / 50°0.62.8012.38.1
Oct64° / 40°0.94.60.410.86.6
Nov49° / 30°1.26.82.99.62.2
Dec38° / 24°1.68.86.28.90.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 16% of December, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34654
44654
54555
64555
74555
84456
94456
104357
114357
124357
134357
144357
154258
164258
174456
184456
194456
204456
214456
224456
234456
244456
254555
264555
274456
284456
294456
304456
314456

Chance of precipitation in December

Any precipitationSnow

Twin Falls gets around 1.6 in of rain and snow over 8.8 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 28% and peaks near 28% on the wettest days, and about 6 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12717
22817
32817
42817
52817
62818
72818
82818
92818
102818
112819
122819
132819
142819
152820
162820
172821
182821
192821
202821
212822
222822
232822
242821
252821
262821
272821
282821
292821
302821
312820

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 06 min at the start of December to 8 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:54 AM to 8:14 AM, and sunset from 5:01 PM to 5:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.17:545:01
29.17:555:01
39.17:565:00
49.07:575:00
59.07:585:00
69.07:595:00
79.08:005:00
89.08:015:00
99.08:025:00
109.08:035:00
118.98:045:00
128.98:045:00
138.98:055:00
148.98:065:00
158.98:075:00
168.98:075:01
178.98:085:01
188.98:095:01
198.98:095:02
208.98:105:02
218.98:105:03
228.98:115:03
238.98:115:03
248.98:125:04
258.98:125:05
268.98:125:05
278.98:135:06
288.98:135:06
298.98:135:07
308.98:135:08
318.98:145:08

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.85 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.85 kWh/m² to a high of 7.98 kWh/m² in July across the year — December's 1.85 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
12.0Dim
22.0Dim
31.9Dim
41.9Dim
51.9Dim
61.9Dim
71.9Dim
81.9Dim
91.9Dim
101.8Dim
111.8Dim
121.8Dim
131.8Dim
141.8Dim
151.8Dim
161.8Dim
171.8Dim
181.8Dim
191.8Dim
201.8Dim
211.8Dim
221.8Dim
231.8Dim
241.8Dim
251.9Dim
261.9Dim
271.9Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Is December a good time to visit Twin Falls?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.0
Sightseeing
11th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Twin Falls.

What to pack for Twin Falls in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Twin Falls sees daytime highs around 38°F and nights near 24°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

UV index in Twin Falls in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Twin Falls peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 19UV 9Dec 13UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr5Moderate
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec2Low

Air quality in Twin Falls in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Twin Falls is worst in August — around 19 µg/m³ PM2.5 (moderate), about 3.3× the cleanest month (December, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1918 µg/m³Dec 186 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar10Good
Apr9Good
May9Good
Jun8Good
Jul16Moderate
Aug19Moderate
Sep17Moderate
Oct8Good
Nov7Good
Dec6Good
Location & terrain

Where is Twin Falls?

Twin Falls sits at 42.6°N, 114.5°W, 3,734 ft above sea level, in United States. The nearest listed city is Pocatello, 104 mi away.

Topography around Twin Falls

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Twin Falls.

Within 2 miles, the terrain around Twin Falls has only modest variations in elevation — a maximum elevation change of 220 ft around an average of 3,727 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,634 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,808 ft.

The land around Twin Falls is covered by artificial surfaces (52%) within 2 miles, cropland (57%) and grassland (30%) within 10 miles, and grassland (73%) and cropland (22%) within 50 miles.

2 miles
220 ft
10 miles
1,634 ft
50 miles
7,808 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Pocatello 104 mi · Boise 114 mi · Kuna 118 mi · Meridian 121 mi · Eagle 124 mi · Nampa 126 mi · Caldwell 135 mi · Elko 137 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Twin Falls (42.563°, -114.4609°, elevation 3,734 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).