Sunnyside weather in January

In January, Sunnyside sees average daytime highs of 40°F and overnight lows near 28°F, with 1.5 in of precipitation across 9.2 wet days and about 8.8 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 20% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 30 min at the start of January to 9 h 18 min by month's end. Set against the rest of the year, January is Sunnyside's 12th-clearest and 11th-windiest month. For the whole year in context, see Sunnyside's year-round climate.

Daytime high
40°
11th warmest
Overnight low
28°
2nd coldest
Precipitation
1.5 in
9.2 wet days
Daylight
8 h 48 min
7:46 AM – 4:33 PM
Cloud cover
70%
12th clearest
Wind
5 mph
11th windiest
Solar energy
1.52 kWh/m²
Travel score
0.1
out of 10

Sunnyside is city in Yakima County, Washington, United States.

Density
950/km²
people per km²
Founded
1902

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

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 Sunnyside reaches about 40°F in the afternoon and slips back to 28°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 28°F and 51°F. Set against its neighbours, January runs on par with December and about 7°F cooler than February.

20°30°40°50°60°151015202531
Avg high (°F)Avg low (°F)
13827
23827
33827
43827
53827
63827
73827
83827
93827
103927
113927
123927
133927
143927
153928
164028
174028
184028
194028
204028
214028
224128
234128
244129
254129
264229
274229
284229
294229
304329
314329

How January really feels in Sunnyside

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
0
heat index over the day's high
Days feeling ≤ 32°F
31
wind chill below the day's low

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

Sunnyside 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.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan40° / 28°1.59.23.58.80.1
Feb47° / 31°1.16.31.9101.5
Mar55° / 36°1.06.60.611.63.9
Apr65° / 43°0.74.60.113.36.5
May75° / 51°0.74.2014.77.7
Jun82° / 57°0.43015.57.2
Jul91° / 63°0.21.3015.24.6
Aug90° / 61°0.21.10145.1
Sep80° / 53°0.31.9012.38.0
Oct64° / 43°1.05.10.110.76.4
Nov48° / 34°1.37.819.22.0
Dec39° / 28°1.793.58.50.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 20% 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 65%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13367
23466
33466
43466
53367
63367
73466
83466
93367
103367
113268
123268
133367
143367
153367
163367
173466
183466
193466
203466
213565
223565
233565
243664
253664
263664
273763
283763
293763
303763
313763

Chance of precipitation in January

Any precipitationSnow

Sunnyside gets around 1.5 in of rain and snow over 9.2 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 30% and peaks near 33% on the wettest days, and about 4 days bring snow. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
13114
23114
33114
43113
53113
63213
73213
83213
93213
103213
113313
123313
133313
143213
153213
163213
173112
183112
193012
203012
212911
222811
232811
242710
25269
26259
27258
28248
29248
30247
31237

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.

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 January

Winds average 5 mph in January.

Across January, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 30 min at the start of January to 9 h 18 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 7:49 AM to 7:33 AM, and sunset from 4:17 PM to 4:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.57:494:17
28.57:494:18
38.57:494:19
48.57:494:20
58.57:494:21
68.57:494:22
78.67:494:23
88.67:494:24
98.67:494:25
108.67:484:26
118.77:484:27
128.77:484:28
138.77:474:29
148.77:474:30
158.87:464:32
168.87:464:33
178.87:454:34
188.87:454:35
198.97:444:37
208.97:434:38
218.97:434:39
229.07:424:41
239.07:414:42
249.17:404:43
259.17:394:45
269.17:384:46
279.27:384:48
289.27:374:49
299.27:364:50
309.37:354:52
319.37:334:53

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.52 kWh/m².

For context, solar energy here swings from a low near 1.3 kWh/m² to a high of 7.84 kWh/m² in July across the year — January's 1.52 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.4Dim
21.4Dim
31.4Dim
41.4Dim
51.4Dim
61.4Dim
71.4Dim
81.4Dim
91.4Dim
101.4Dim
111.4Dim
121.4Dim
131.5Dim
141.5Dim
151.5Dim
161.5Dim
171.5Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.7Dim
231.7Dim
241.7Dim
251.8Dim
261.8Dim
271.8Dim
281.9Dim
291.9Dim
301.9Dim
312.0Dim
Planning a trip in January

Is January a good time to visit Sunnyside?

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

0.1
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 Sunnyside.

What to pack for Sunnyside in January

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

In January, Sunnyside sees daytime highs around 40°F and nights near 28°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 Sunnyside in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sunnyside peaks around July 16 at about 8 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighVery highHighModerateLowJul 16UV 8Dec 14UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May7Very high
Jun6High
Jul9Very high
Aug6High
Sep5Moderate
Oct4Moderate
Nov1Low
Dec1Low

Air quality in Sunnyside 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 Sunnyside is worst in August — around 30 µg/m³ PM2.5 (moderate), about 4.0× the cleanest month (December, 7 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 2029 µg/m³Dec 178 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar12Good
Apr10Good
May9Good
Jun10Good
Jul13Moderate
Aug30Moderate
Sep23Moderate
Oct10Good
Nov10Good
Dec7Good
Location & terrain

Where is Sunnyside?

Sunnyside sits at 46.3°N, 120.0°W, 745 ft above sea level, in United States. The nearest listed city is Yakima, 30 mi away.

Topography around Sunnyside

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

Within 2 miles, the terrain around Sunnyside has only modest variations in elevation — a maximum elevation change of 289 ft around an average of 764 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,152 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,568 ft.

The land around Sunnyside is covered by cropland (34%), grassland (29%) and artificial surfaces (24%) within 2 miles, grassland (46%) and cropland (38%) within 10 miles, and grassland (62%) and cropland (24%) within 50 miles.

2 miles
289 ft
10 miles
2,152 ft
50 miles
5,568 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Yakima 30 mi · Richland 35 mi · Tri-Cities 39 mi · Kennewick 42 mi · Pasco 43 mi · Hermiston 48 mi · Ellensburg 53 mi · Moses Lake 66 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 Sunnyside (46.3237°, -120.0087°, elevation 745 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).