Yakima weather in September

In September, Yakima sees average daytime highs of 77°F and overnight lows near 49°F, with 0.3 in of rain across 1.9 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 82°F in the first days to 72°F by the end. The sky is clear or mostly clear about 59% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Yakima's 3rd-clearest and 7th-windiest month. For the whole year in context, see Yakima's year-round climate.

Daytime high
77°
4th warmest
Overnight low
49°
9th coldest
Rainfall
0.3 in
1.9 wet days
Daylight
12 h 18 min
5:47 AM – 6:06 PM
Cloud cover
34%
3rd clearest
Wind
4 mph
7th windiest
Solar energy
5.02 kWh/m²
Travel score
8.4
out of 10

Yakima is city in and county seat of Yakima County, Washington, United States.

Density
1,284/km²
people per km²
Founded
1847

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 82°F in the first days to 72°F by the end.

A typical September day in Yakima reaches about 77°F in the afternoon and slips back to 49°F overnight — a 28°F spread between the day's warmth and the night's chill. On most days the high lands between 67°F and 88°F. Set against its neighbours, September runs about 10°F cooler than August and about 15°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18353
28253
38253
48253
58152
68152
78152
88052
98051
108051
117951
127951
137850
147850
157850
167749
177749
187649
197649
207648
217548
227548
237447
247447
257447
267346
277346
287246
297246
307145

How September really feels in Yakima

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 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
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Yakima weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 26°2.310.95.68.80.0
Feb44° / 28°1.67.53.1100.9
Mar53° / 33°1.37.51.311.63.3
Apr62° / 38°0.84.70.113.35.8
May72° / 46°0.74.3014.87.6
Jun80° / 53°0.42.5015.67.8
Jul88° / 58°0.10.8015.25.7
Aug87° / 57°0.10.80146.2
Sep77° / 49°0.31.9012.48.4
Oct62° / 40°1.25.50.110.65.9
Nov47° / 31°2.092.29.21.5
Dec38° / 26°2.610.968.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18218
28119
38119
48119
58020
68020
77921
87822
97723
107624
117525
127426
137327
147327
157228
167228
177228
187129
197228
207228
217228
227228
237228
247327
257327
267426
277327
287327
297426
307327

Chance of precipitation in September

Any precipitation

Yakima gets around 0.3 in of rain over 1.9 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 6% and peaks near 9% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
13
24
34
44
54
65
75
85
96
106
116
126
136
146
156
166
176
186
197
207
217
227
237
247
258
268
278
289
299
309

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991

Wind in September

Winds average 4 mph in September.

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

0246810151015202530
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 5:27 AM to 6:05 AM, and sunset from 6:37 PM to 5:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:276:37
213.15:286:35
313.15:296:33
413.05:316:31
512.95:326:29
612.95:336:27
712.85:356:25
812.85:366:23
912.75:376:21
1012.75:396:19
1112.65:406:17
1212.65:416:14
1312.55:436:12
1412.45:446:10
1512.45:456:08
1612.35:476:06
1712.35:486:04
1812.25:496:02
1912.25:516:00
2012.15:525:58
2112.05:535:56
2212.05:555:54
2311.95:565:52
2411.95:575:50
2511.85:595:48
2611.86:005:45
2711.76:015:43
2811.66:035:41
2911.66:045:39
3011.56:055:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.02 kWh/m².

For context, solar energy here swings from a low near 1.31 kWh/m² to a high of 7.84 kWh/m² in July across the year — September's 5.02 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.8Bright
45.7Bright
55.7Bright
65.6Bright
75.5Bright
85.5Bright
95.4Bright
105.3Bright
115.3Bright
125.2Bright
135.2Bright
145.1Bright
155.0Bright
165.0Bright
174.9Bright
184.8Bright
194.8Bright
204.7Bright
214.6Bright
224.6Bright
234.5Bright
244.5Bright
254.4Bright
264.3Bright
274.3Bright
284.2Bright
294.2Bright
304.1Bright
Planning a trip in September

Is September a good time to visit Yakima?

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

8.4
Sightseeing
1st-best month of the year
7.5
Beach & pool
4th-best month of the year

September is one of the better times to visit Yakima for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Yakima in September

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

In September, Yakima sees daytime highs around 77°F and nights near 49°F. Worth packing: light clothes and sun protection.

light clothessun protection

UV index in Yakima in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Yakima peaks around July 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 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 17UV 8Dec 12UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May7Very high
Jun6High
Jul9Very high
Aug7High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Yakima in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Yakima is worst in August — around 51 µg/m³ PM2.5 (poor), about 10.9× the cleanest month (December, 5 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodPoorModerateGoodAug 1948 µg/m³Dec 215 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb6Good
Mar8Good
Apr8Good
May8Good
Jun8Good
Jul11Good
Aug51Poor
Sep31Moderate
Oct8Good
Nov7Good
Dec5Good
Location & terrain

Where is Yakima?

Yakima sits at 46.6°N, 120.5°W, 1,070 ft above sea level, in United States. The nearest listed city is Ellensburg, 27 mi away.

Topography around Yakima

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

Within 2 miles, the terrain around Yakima has only modest variations in elevation — a maximum elevation change of 669 ft around an average of 1,076 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,356 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,533 ft.

The land around Yakima is covered by artificial surfaces (58%) within 2 miles, grassland (64%) within 10 miles, and grassland (51%) and trees (35%) within 50 miles.

2 miles
669 ft
10 miles
2,356 ft
50 miles
7,533 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Ellensburg 27 mi · Sunnyside 30 mi · Wenatchee 58 mi · Richland 62 mi · Tri-Cities 67 mi · Moses Lake 68 mi · Kennewick 71 mi · Pasco 71 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 Yakima (46.6021°, -120.5059°, elevation 1,070 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).