Boise weather in January

In January, Boise sees average daytime highs of 40°F and overnight lows near 27°F, with 1.8 in of precipitation across 9.5 wet days and about 9.1 hours of daylight. It is the 11th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 38°F in the first days to 42°F by the end. The sky is clear or mostly clear about 28% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 48 min at the start of January to 9 h 36 min by month's end. Set against the rest of the year, January is Boise's 12th-clearest and 8th-windiest month. For the whole year in context, see Boise's year-round climate.

Daytime high: 40°; 11th warmest
Overnight low: 27°; 1st coldest
Precipitation: 1.8 in; 9.5 wet days
Daylight: 9 h 06 min; 8:21 AM – 5:27 PM
Cloud cover: 63%; 12th clearest
Wind: 6 mph; 8th windiest
Solar energy: 1.95 kWh/m²
Travel score: 0.0; out of 10

Boise is capital city of the U.S. state of Idaho and seat of Ada County.

Density: 1/km²; people per km²
Founded: 1863

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

← December Boise year-round climate February →Best places to visit in January

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 38°F in the first days to 42°F by the end.

A typical January day in Boise reaches about 40°F in the afternoon and slips back to 27°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 30°F and 49°F. Set against its neighbours, January runs on par with December and about 6°F cooler than February.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°F)	38	38	38	38	38	38	38	39	39	39	39	39	39	39	40	40	40	40	40	40	40	40	41	41	41	41	41	42	42	42	42
Avg low (°F)	26	26	26	26	26	26	26	26	26	26	26	27	27	27	27	27	27	27	27	27	27	27	27	27	27	28	28	28	28	28	28

	Avg high (°F)	Avg low (°F)
1	38	26
2	38	26
3	38	26
4	38	26
5	38	26
6	38	26
7	38	26
8	39	26
9	39	26
10	39	26
11	39	26
12	39	27
13	39	27
14	39	27
15	40	27
16	40	27
17	40	27
18	40	27
19	40	27
20	40	27
21	40	27
22	40	27
23	41	27
24	41	27
25	41	27
26	41	28
27	41	28
28	42	28
29	42	28
30	42	28
31	42	28

How January really feels in Boise

Once humidity and wind are folded in, January 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

heat index over the day's high

Days feeling ≤ 32°F

wind chill below the day's low

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

Boise weather by month

How January compares with the rest of the year at a glance. January is the 11th-warmest and 2nd-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	40° / 27°	1.8	9.5	4.8	9.1	0.0
Feb	46° / 30°	1.2	7.7	3	10.2	1.2
Mar	55° / 36°	1.4	8.9	1.1	11.6	3.7
Apr	63° / 41°	1.2	7.2	0.3	13.2	5.8
May	72° / 48°	1.2	5.9	0.1	14.5	7.5
Jun	81° / 55°	0.6	3.2	0	15.2	7.4
Jul	92° / 63°	0.1	0.9	0	14.9	4.4
Aug	91° / 62°	0.1	0.7	0	13.8	4.9
Sep	80° / 54°	0.4	2.2	0	12.3	8.1
Oct	65° / 43°	0.9	4.3	0.1	10.8	6.8
Nov	49° / 33°	1.4	7.9	2	9.5	2.2
Dec	39° / 27°	2.0	10.1	5.2	8.8	0.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of January, with mostly cloudy or overcast conditions the remaining 59%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	40	40	40	39	40	40	41	40	40	40	41	41	42	41	41	41	41	42	42	42	42	42	42	42	42	42	42	43	44	44	44
Cloudier (%)	60	60	60	61	60	60	59	60	60	60	59	59	58	59	59	59	59	58	58	58	58	58	58	58	58	58	58	57	56	56	56

	Clearer (%)	Cloudier (%)
1	40	60
2	40	60
3	40	60
4	39	61
5	40	60
6	40	60
7	41	59
8	40	60
9	40	60
10	40	60
11	41	59
12	41	59
13	42	58
14	41	59
15	41	59
16	41	59
17	41	59
18	42	58
19	42	58
20	42	58
21	42	58
22	42	58
23	42	58
24	42	58
25	42	58
26	42	58
27	42	58
28	43	57
29	44	56
30	44	56
31	44	56

Chance of precipitation in January

Any precipitationSnow

Boise gets around 1.8 in of rain and snow over 9.5 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 31% and peaks near 32% on the wettest days, and about 5 days bring snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	31	31	31	31	31	31	31	31	31	31	31	32	32	32	32	32	32	32	32	32	31	31	31	30	30	29	29	28	27	26	26
Snow chance (%)	18	18	18	18	18	17	17	17	16	16	16	16	16	16	16	16	15	15	15	15	15	15	15	15	14	14	14	13	13	13	12

	Rain chance (%)	Snow chance (%)
1	31	18
2	31	18
3	31	18
4	31	18
5	31	18
6	31	17
7	31	17
8	31	17
9	31	16
10	31	16
11	31	16
12	32	16
13	32	16
14	32	16
15	32	16
16	32	16
17	32	15
18	32	15
19	32	15
20	32	15
21	31	15
22	31	15
23	31	15
24	30	15
25	30	14
26	29	14
27	29	14
28	28	13
29	27	13
30	26	13
31	26	12

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

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

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in January

Winds average 6 mph in January.

Across January, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (mph)	7	7	7	7	7	7	7	7	7	7	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (mph)	Feels
1	7	calm
2	7	calm
3	7	calm
4	7	calm
5	7	calm
6	7	calm
7	7	calm
8	7	calm
9	7	calm
10	7	calm
11	6	calm
12	6	calm
13	6	calm
14	6	calm
15	6	calm
16	6	calm
17	6	calm
18	6	calm
19	6	calm
20	6	calm
21	6	calm
22	6	calm
23	6	calm
24	6	calm
25	6	calm
26	6	calm
27	6	calm
28	6	calm
29	6	calm
30	6	calm
31	6	calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 48 min at the start of January to 9 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over January. Sunrise moves from 8:24 AM to 8:11 AM, and sunset from 5:12 PM to 5:46 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	8.8	8.8	8.8	8.8	8.9	8.9	8.9	8.9	8.9	8.9	9.0	9.0	9.0	9.0	9.1	9.1	9.1	9.1	9.2	9.2	9.2	9.3	9.3	9.3	9.4	9.4	9.4	9.5	9.5	9.5	9.6
Sunrise (AM)	8:24	8:24	8:24	8:24	8:24	8:24	8:24	8:24	8:24	8:23	8:23	8:23	8:23	8:22	8:22	8:21	8:21	8:20	8:20	8:19	8:19	8:18	8:17	8:17	8:16	8:15	8:14	8:13	8:13	8:12	8:11
Sunset (PM)	5:12	5:13	5:14	5:15	5:15	5:16	5:17	5:18	5:19	5:20	5:21	5:22	5:24	5:25	5:26	5:27	5:28	5:29	5:30	5:32	5:33	5:34	5:35	5:37	5:38	5:39	5:40	5:42	5:43	5:44	5:46

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	8.8	8:24	5:12
2	8.8	8:24	5:13
3	8.8	8:24	5:14
4	8.8	8:24	5:15
5	8.9	8:24	5:15
6	8.9	8:24	5:16
7	8.9	8:24	5:17
8	8.9	8:24	5:18
9	8.9	8:24	5:19
10	8.9	8:23	5:20
11	9.0	8:23	5:21
12	9.0	8:23	5:22
13	9.0	8:23	5:24
14	9.0	8:22	5:25
15	9.1	8:22	5:26
16	9.1	8:21	5:27
17	9.1	8:21	5:28
18	9.1	8:20	5:29
19	9.2	8:20	5:30
20	9.2	8:19	5:32
21	9.2	8:19	5:33
22	9.3	8:18	5:34
23	9.3	8:17	5:35
24	9.3	8:17	5:37
25	9.4	8:16	5:38
26	9.4	8:15	5:39
27	9.4	8:14	5:40
28	9.5	8:13	5:42
29	9.5	8:13	5:43
30	9.5	8:12	5:44
31	9.6	8:11	5:46

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.95 kWh/m².

For context, solar energy here swings from a low near 1.66 kWh/m² to a high of 8.03 kWh/m² in July across the year — January's 1.95 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	1.7	1.7	1.7	1.8	1.8	1.8	1.8	1.8	1.8	1.8	1.8	1.9	1.9	1.9	1.9	1.9	2.0	2.0	2.0	2.0	2.1	2.1	2.1	2.2	2.2	2.2	2.3	2.3	2.3	2.4	2.4
Level	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	1.7	Dim
2	1.7	Dim
3	1.7	Dim
4	1.8	Dim
5	1.8	Dim
6	1.8	Dim
7	1.8	Dim
8	1.8	Dim
9	1.8	Dim
10	1.8	Dim
11	1.8	Dim
12	1.9	Dim
13	1.9	Dim
14	1.9	Dim
15	1.9	Dim
16	1.9	Dim
17	2.0	Dim
18	2.0	Dim
19	2.0	Moderate
20	2.0	Moderate
21	2.1	Moderate
22	2.1	Moderate
23	2.1	Moderate
24	2.2	Moderate
25	2.2	Moderate
26	2.2	Moderate
27	2.3	Moderate
28	2.3	Moderate
29	2.3	Moderate
30	2.4	Moderate
31	2.4	Moderate

Planning a trip in January

Is January a good time to visit Boise?

Our two travel scores rate January 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

January is a weaker month for outdoor sightseeing in Boise.

What to pack for Boise in January

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

In January, Boise sees daytime highs around 40°F and nights near 27°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

UV index in Boise in January

LowModerateHighVery highExtreme

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

Under clear skies, the midday UV index in Boise peaks around July 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 1 (low).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	2	2	4	5	8	9	9	7	6	4	2	1
Level	Low	Moderate	Moderate	High	Very high	Very high	Very high	Very high	High	Moderate	Low	Low

	UV index (midday)	Level
Jan	2	Low
Feb	2	Moderate
Mar	4	Moderate
Apr	5	High
May	8	Very high
Jun	9	Very high
Jul	9	Very high
Aug	7	Very high
Sep	6	High
Oct	4	Moderate
Nov	2	Low
Dec	1	Low

Air quality in Boise in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Boise is worst in August — around 45 µg/m³ PM2.5 (poor), about 6.0× the cleanest month (December, 7 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	8	9	10	10	10	8	20	45	21	15	9	7
Level	Good	Good	Good	Good	Good	Good	Moderate	Poor	Moderate	Moderate	Good	Good

	PM2.5 (µg/m³)	Level
Jan	8	Good
Feb	9	Good
Mar	10	Good
Apr	10	Good
May	10	Good
Jun	8	Good
Jul	20	Moderate
Aug	45	Poor
Sep	21	Moderate
Oct	15	Moderate
Nov	9	Good
Dec	7	Good

Location & terrain

Where is Boise?

Boise sits at 43.6°N, 116.2°W, 2,700 ft above sea level, in United States. The nearest listed city is Meridian, 9.3 mi away.

Topography around Boise

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

Within 2 miles, the terrain around Boise has only modest variations in elevation — a maximum elevation change of 535 ft around an average of 2,756 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 4,003 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,516 ft.

The land around Boise is covered by trees (42%) and artificial surfaces (39%) within 2 miles, grassland (55%) and trees (21%) within 10 miles, and grassland (61%) and trees (20%) within 50 miles.

2 miles

535 ft

trees 42%

10 miles

4,003 ft

grassland 55%

50 miles

7,516 ft

grassland 61%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwater

← December Boise year-round climate February →Best places to visit in January

January weather nearby: Meridian 9.3 mi · Eagle 9.3 mi · Kuna 14 mi · Nampa 19 mi · Caldwell 24 mi · Twin Falls 114 mi · Pendleton 191 mi · Elko 193 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

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 Boise (43.6135°, -116.2035°, elevation 2,700 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).

	Avg high (°F)	Avg low (°F)
1	38	26
2	38	26
3	38	26
4	38	26
5	38	26
6	38	26
7	38	26
8	39	26
9	39	26
10	39	26
11	39	26
12	39	27
13	39	27
14	39	27
15	40	27
16	40	27
17	40	27
18	40	27
19	40	27
20	40	27
21	40	27
22	40	27
23	41	27
24	41	27
25	41	27
26	41	28
27	41	28
28	42	28
29	42	28
30	42	28
31	42	28

	Clearer (%)	Cloudier (%)
1	40	60
2	40	60
3	40	60
4	39	61
5	40	60
6	40	60
7	41	59
8	40	60
9	40	60
10	40	60
11	41	59
12	41	59
13	42	58
14	41	59
15	41	59
16	41	59
17	41	59
18	42	58
19	42	58
20	42	58
21	42	58
22	42	58
23	42	58
24	42	58
25	42	58
26	42	58
27	42	58
28	43	57
29	44	56
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	31	18
2	31	18
3	31	18
4	31	18
5	31	18
6	31	17
7	31	17
8	31	17
9	31	16
10	31	16
11	31	16
12	32	16
13	32	16
14	32	16
15	32	16
16	32	16
17	32	15
18	32	15
19	32	15
20	32	15
21	31	15
22	31	15
23	31	15
24	30	15
25	30	14
26	29	14
27	29	14
28	28	13
29	27	13
30	26	13
31	26	12

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	38	26
2	38	26
3	38	26
4	38	26
5	38	26
6	38	26
7	38	26
8	39	26
9	39	26
10	39	26
11	39	26
12	39	27
13	39	27
14	39	27
15	40	27
16	40	27
17	40	27
18	40	27
19	40	27
20	40	27
21	40	27
22	40	27
23	41	27
24	41	27
25	41	27
26	41	28
27	41	28
28	42	28
29	42	28
30	42	28
31	42	28

	Clearer (%)	Cloudier (%)
1	40	60
2	40	60
3	40	60
4	39	61
5	40	60
6	40	60
7	41	59
8	40	60
9	40	60
10	40	60
11	41	59
12	41	59
13	42	58
14	41	59
15	41	59
16	41	59
17	41	59
18	42	58
19	42	58
20	42	58
21	42	58
22	42	58
23	42	58
24	42	58
25	42	58
26	42	58
27	42	58
28	43	57
29	44	56
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	31	18
2	31	18
3	31	18
4	31	18
5	31	18
6	31	17
7	31	17
8	31	17
9	31	16
10	31	16
11	31	16
12	32	16
13	32	16
14	32	16
15	32	16
16	32	16
17	32	15
18	32	15
19	32	15
20	32	15
21	31	15
22	31	15
23	31	15
24	30	15
25	30	14
26	29	14
27	29	14
28	28	13
29	27	13
30	26	13
31	26	12

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	38	26
2	38	26
3	38	26
4	38	26
5	38	26
6	38	26
7	38	26
8	39	26
9	39	26
10	39	26
11	39	26
12	39	27
13	39	27
14	39	27
15	40	27
16	40	27
17	40	27
18	40	27
19	40	27
20	40	27
21	40	27
22	40	27
23	41	27
24	41	27
25	41	27
26	41	28
27	41	28
28	42	28
29	42	28
30	42	28
31	42	28

	Clearer (%)	Cloudier (%)
1	40	60
2	40	60
3	40	60
4	39	61
5	40	60
6	40	60
7	41	59
8	40	60
9	40	60
10	40	60
11	41	59
12	41	59
13	42	58
14	41	59
15	41	59
16	41	59
17	41	59
18	42	58
19	42	58
20	42	58
21	42	58
22	42	58
23	42	58
24	42	58
25	42	58
26	42	58
27	42	58
28	43	57
29	44	56
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	31	18
2	31	18
3	31	18
4	31	18
5	31	18
6	31	17
7	31	17
8	31	17
9	31	16
10	31	16
11	31	16
12	32	16
13	32	16
14	32	16
15	32	16
16	32	16
17	32	15
18	32	15
19	32	15
20	32	15
21	31	15
22	31	15
23	31	15
24	30	15
25	30	14
26	29	14
27	29	14
28	28	13
29	27	13
30	26	13
31	26	12

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100