Idaho Falls weather in December

In December, Idaho Falls sees average daytime highs of 31°F and overnight lows near 18°F, with 1.5 in of precipitation across 9.4 wet days and about 8.8 hours of daylight. It is the 11th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 34°F in the first days to 29°F by the end. The sky is clear or mostly clear about 23% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 hours at the start of December to 8 h 48 min by month's end. Set against the rest of the year, December is Idaho Falls's 12th-clearest and 11th-windiest month. For the whole year in context, see Idaho Falls's year-round climate.

Daytime high
31°
11th warmest
Overnight low
18°
2nd coldest
Precipitation
1.5 in
9.4 wet days
Daylight
8 h 48 min
8:01 AM – 4:48 PM
Cloud cover
66%
12th clearest
Wind
6 mph
11th windiest
Solar energy
1.7 kWh/m²
Travel score
0.0
out of 10

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

Density
988/km²
people per km²
Founded
1864

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 34°F in the first days to 29°F by the end.

A typical December day in Idaho Falls reaches about 31°F in the afternoon and slips back to 18°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 20°F and 41°F. Set against its neighbours, December runs about 11°F cooler than November and on par with January.

20°40°151015202531
Avg high (°F)Avg low (°F)
13521
23520
33420
43420
53420
63319
73319
83319
93319
103219
113218
123218
133218
143118
153117
163117
173117
183117
193017
203017
213016
223016
233016
243016
253016
263016
272916
282916
292916
302916
312916

How December really feels in Idaho 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
31 feel bitter (≤ 14°F)

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

Idaho Falls weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan31° / 17°1.49.410.39.10.0
Feb36° / 21°1.17.87.310.20.0
Mar47° / 29°1.49.24.611.61.6
Apr56° / 34°1.811.2313.23.7
May66° / 42°2.19.60.814.56.1
Jun76° / 50°1.260.115.27.5
Jul87° / 57°0.53.3014.95.9
Aug85° / 55°0.53.5013.86.5
Sep74° / 47°1.04.20.112.38.0
Oct58° / 36°1.36.51.210.85.0
Nov43° / 26°1.27.45.59.50.7
Dec31° / 18°1.59.49.78.80.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in December, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 63%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13961
23961
33862
43862
54060
63961
73961
83961
93862
103862
113862
123763
133763
143763
153763
163862
173763
183763
193664
203763
213664
223664
233664
243664
253664
263763
273763
283664
293664
303664
313565

Chance of precipitation in December

Any precipitationSnow

Idaho Falls gets around 1.5 in of rain and snow over 9.4 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 30% and peaks near 32% on the wettest days, and about 10 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
13228
23228
33229
43229
53229
63130
73130
83130
93030
103030
112931
122931
132831
142831
152831
162831
172831
182831
192831
202831
212831
222831
232931
242931
252931
262931
272931
282931
293032
303032
313032

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 6 mph in December.

Across December, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 hours at the start of December to 8 h 48 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 7:48 AM to 8:07 AM, and sunset from 4:48 PM to 4:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.07:484:48
29.07:494:48
39.07:504:48
48.97:514:47
58.97:524:47
68.97:534:47
78.97:544:47
88.97:544:47
98.97:554:47
108.87:564:47
118.87:574:47
128.87:584:47
138.87:594:47
148.87:594:47
158.88:004:48
168.88:014:48
178.88:014:48
188.88:024:48
198.88:034:49
208.88:034:49
218.88:044:50
228.88:044:50
238.88:054:51
248.88:054:51
258.88:054:52
268.88:064:52
278.88:064:53
288.88:064:53
298.88:074:54
308.88:074:55
318.88:074:56

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.7 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 7.94 kWh/m² in July across the year — December's 1.7 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.8Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Is December a good time to visit Idaho Falls?

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

0.0
Sightseeing
10th-best month of the year
0.0
Beach & pool
8th-best month of the year

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

What to pack for Idaho Falls in December

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

In December, Idaho Falls sees daytime highs around 31°F and nights near 18°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 Idaho 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 Idaho Falls peaks around July 12 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateVery highHighModerateLowJul 12UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr5Moderate
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec2Low

Air quality in Idaho 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 Idaho Falls is worst in August — around 20 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (December, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1420 µg/m³Dec 197 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar10Good
Apr10Good
May10Good
Jun9Good
Jul17Moderate
Aug20Moderate
Sep14Moderate
Oct9Good
Nov9Good
Dec7Good
Location & terrain

Where is Idaho Falls?

Idaho Falls sits at 43.5°N, 112.0°W, 4,705 ft above sea level, in United States. The nearest listed city is Rexburg, 28 mi away.

Topography around Idaho Falls

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

Within 2 miles, the terrain around Idaho Falls has only modest variations in elevation — a maximum elevation change of 95 ft around an average of 4,698 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,693 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,561 ft.

The land around Idaho Falls is covered by artificial surfaces (33%) and trees (22%) within 2 miles, cropland (45%) and grassland (38%) within 10 miles, and grassland (54%) and cropland (22%) within 50 miles.

2 miles
95 ft
10 miles
1,693 ft
50 miles
5,561 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Rexburg 28 mi · Pocatello 46 mi · Conda 57 mi · Logan 120 mi · Brigham City 135 mi · Twin Falls 137 mi · North Ogden 149 mi · Ogden 155 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 Idaho Falls (43.4666°, -112.0341°, elevation 4,705 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).