Ellensburg weather in September

In September, Ellensburg sees average daytime highs of 71°F and overnight lows near 47°F, with 0.6 in of rain across 3.4 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 76°F in the first days to 67°F by the end. The sky is clear or mostly clear about 55% 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 Ellensburg's 3rd-clearest and 6th-windiest month. For the whole year in context, see Ellensburg's year-round climate.

Daytime high
71°
4th warmest
Overnight low
47°
9th coldest
Rainfall
0.6 in
3.4 wet days
Daylight
12 h 18 min
5:47 AM – 6:06 PM
Cloud cover
38%
3rd clearest
Wind
6 mph
6th windiest
Solar energy
4.88 kWh/m²
Travel score
8.0
out of 10

Ellensburg is city in Kittitas County, Washington, United States.

Density
1,052/km²
people per km²
Founded
1883

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 76°F in the first days to 67°F by the end.

A typical September day in Ellensburg reaches about 71°F in the afternoon and slips back to 47°F overnight — a 24°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 83°F. Set against its neighbours, September runs about 9°F cooler than August and about 15°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17651
27651
37651
47650
57550
67550
77550
87449
97449
107449
117349
127349
137348
147248
157248
167147
177147
187147
197047
207046
217046
226946
236946
246945
256845
266845
276744
286744
296644
306643

How September really feels in Ellensburg

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.

Ellensburg 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
Jan34° / 24°2.712.68.78.70.0
Feb39° / 26°1.99.16.3100.0
Mar47° / 30°1.89.94.411.61.5
Apr56° / 36°1.38.10.813.33.9
May65° / 43°1.37.3014.86.3
Jun72° / 49°0.74.6015.67.7
Jul81° / 55°0.32015.37.9
Aug81° / 54°0.31.80148.1
Sep71° / 47°0.63.4012.48.0
Oct57° / 38°1.67.20.510.64.4
Nov42° / 29°2.611.24.79.10.5
Dec33° / 23°3.112.79.68.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 55% 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 29%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17723
27822
37822
47723
57723
67624
77525
87525
97327
107327
117129
127129
136931
146931
156832
166832
176832
186634
196733
206733
216733
226832
236832
246832
256931
266931
276931
286832
296832
306733

Chance of precipitation in September

Any precipitation

Ellensburg gets around 0.6 in of rain over 3.4 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 11% and peaks near 14% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
18
28
38
48
59
69
79
810
910
1011
1111
1212
1312
1412
1512
1612
1712
1812
1912
2012
2113
2213
2313
2413
2513
2613
2713
2814
2914
3014

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
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

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
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
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 5:26 AM to 6:06 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)
113.25:266:37
213.15:286:35
313.15:296:33
413.05:306:31
513.05:326:29
612.95:336:27
712.85:346:25
812.85:366:23
912.75:376:21
1012.75:386:19
1112.65:406:17
1212.65:416:15
1312.55:436:13
1412.45:446:11
1512.45:456:09
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
2611.86:005:46
2711.76:025:43
2811.66:035:41
2911.66:045:39
3011.56:065:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.88 kWh/m².

For context, solar energy here swings from a low near 1.27 kWh/m² to a high of 7.71 kWh/m² in July across the year — September's 4.88 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.8Bright
25.7Bright
35.6Bright
45.6Bright
55.5Bright
65.5Bright
75.4Bright
85.3Bright
95.3Bright
105.2Bright
115.1Bright
125.1Bright
135.0Bright
144.9Bright
154.9Bright
164.8Bright
174.8Bright
184.7Bright
194.6Bright
204.6Bright
214.5Bright
224.5Bright
234.4Bright
244.3Bright
254.3Bright
264.2Bright
274.2Bright
284.1Bright
294.1Bright
304.0Moderate
Planning a trip in September

Is September a good time to visit Ellensburg?

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

8.0
Sightseeing
2nd-best month of the year
5.4
Beach & pool
4th-best month of the year

September is one of the better times to visit Ellensburg for general sightseeing.

What to pack for Ellensburg in September

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

In September, Ellensburg sees daytime highs around 71°F and nights near 47°F. Worth packing: sun protection. About 3 days see rain.

sun protection

UV index in Ellensburg 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 Ellensburg 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 Ellensburg 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 Ellensburg is worst in September — around 32 µg/m³ PM2.5 (moderate), about 7.6× the cleanest month (December, 4 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1031 µg/m³Dec 204 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb6Good
Mar8Good
Apr8Good
May8Good
Jun8Good
Jul9Good
Aug29Moderate
Sep32Moderate
Oct8Good
Nov6Good
Dec4Good
Location & terrain

Where is Ellensburg?

Ellensburg sits at 47.0°N, 120.5°W, 1,542 ft above sea level, in United States. The nearest listed city is Yakima, 27 mi away.

Topography around Ellensburg

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

Within 2 miles, the terrain around Ellensburg has only modest variations in elevation — a maximum elevation change of 236 ft around an average of 1,562 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,720 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 8,714 ft.

The land around Ellensburg is covered by grassland (35%), artificial surfaces (25%) and trees (22%) within 2 miles, grassland (63%) and cropland (26%) within 10 miles, and grassland (45%) and trees (40%) within 50 miles.

2 miles
236 ft
10 miles
2,720 ft
50 miles
8,714 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Yakima 27 mi · Wenatchee 32 mi · Sunnyside 53 mi · Moses Lake 60 mi · Maple Valley 75 mi · Richland 78 mi · Covington 78 mi · Bonney Lake 78 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 Ellensburg (46.9965°, -120.5478°, elevation 1,542 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).