Sunnyside in Fall

In fall (September, October and November), Sunnyside sees average daytime highs around 64°F and overnight lows near 43°F, with 2.6 in of precipitation over about 15 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.

Over the season highs ease from about 85°F in early September to 43°F by late November. The sky is clear or mostly clear about 44% of the time across fall, and the air most often feels dry.

Fall is Sunnyside's 3rd-best season to visit on our travel score. For the whole year in context, see Sunnyside's year-round climate.

Avg daytime high
64°F
3rd-warmest season
Avg overnight low
43°F
Precipitation
2.6 in
15 wet days
Avg wind
5 mph
Travel score
5.5
3rd-best season
Months
Sep · Oct · Nov

Temperature in Sunnyside in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 85°F in early September to 43°F by late November.

A typical fall day in Sunnyside reaches about 64°F and drops to 43°F overnight. The warmest of the three months is September, the coolest November.

20°40°60°80°100°SepOctNov

How fall really feels in Sunnyside

Once humidity and wind are folded in, fall brings about 0 days that feel above 90°F and 24 that feel at or below 32°F.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
24
wind chill below the day's low

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

Sunnyside weather by month

How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.

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 Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 44% of the time across fall.

0%25%50%75%100%SepOctNov

Chance of precipitation in Fall

Any precipitationSnow

Sunnyside gets around 2.6 in of rain and snow over 15 wet days across fall. The line is the day-by-day chance of measurable precipitation.

0%10%20%30%40%SepOctNov

Humidity in Fall

DryComfortableHumidMuggyOppressiveMiserable

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

0%25%50%75%100%SepOctNov

Wind in Fall

Winds average 5 mph across fall.

0246810SepOctNov

Sunrise & sunset in Fall

DaylightNight

Daylight runs from about 13 h 12 min in early September to 8 h 42 min by late November. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMSepOctNov

Solar energy in Fall

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across fall, about 3.3 kWh/m².

0246SepOctNov
Planning a trip in fall

Is fall a good time to visit Sunnyside?

Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

5.5
Sightseeing
3rd-best month of the year
3.4
Beach & pool
2nd-best month of the year

fall is a reasonable time to visit Sunnyside for sightseeing.

What to pack for Sunnyside in Fall

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

In fall, Sunnyside sees daytime highs around 64°F and nights near 43°F. Pack a warm layer. Worth having: light clothes and sun protection. About 15 days see rain.

a warm layerlight clothessun protection

UV index in Sunnyside in Fall

LowModerateHighVery highExtreme

Clear-sky midday UV across fall averages around 3 — enough to warrant sun protection. 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 Fall

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where fall 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
Fall 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.