Spokane Valley weather in September

In September, Spokane Valley sees average daytime highs of 73°F and overnight lows near 49°F, with 0.9 in of precipitation across 4.4 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 78°F in the first days to 68°F by the end. The sky is clear or mostly clear about 50% 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 Spokane Valley's 3rd-clearest and 9th-windiest month. For the whole year in context, see Spokane Valley's year-round climate.

Daytime high
73°
4th warmest
Overnight low
49°
9th coldest
Precipitation
0.9 in
4.4 wet days
Daylight
12 h 18 min
5:33 AM – 5:53 PM
Cloud cover
41%
3rd clearest
Wind
5 mph
9th windiest
Solar energy
4.72 kWh/m²
Travel score
7.8
out of 10

Spokane Valley is city in Washington, United States of America.

Density
963/km²
people per km²
Founded
2003

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 78°F in the first days to 68°F by the end.

A typical September day in Spokane Valley reaches about 73°F in the afternoon and slips back to 49°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 85°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)
17853
27853
37852
47752
57752
67752
77651
87651
97551
107551
117550
127450
137450
147349
157349
167349
177249
187248
197248
207148
217147
227047
237047
247047
256946
266946
276846
286845
296745
306745

How September really feels in Spokane Valley

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.

Spokane Valley 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
Jan35° / 25°3.113.38.98.70.0
Feb40° / 26°2.110.66.39.90.0
Mar48° / 31°2.712.84.111.61.6
Apr57° / 37°2.3111.213.33.8
May66° / 45°2.08.6014.96.3
Jun73° / 51°1.56.6015.77.2
Jul84° / 57°0.63015.47.0
Aug83° / 57°0.52.6014.17.2
Sep73° / 49°0.94.40.112.47.8
Oct58° / 39°2.08.50.310.64.5
Nov43° / 31°3.313.259.10.6
Dec35° / 25°3.412.898.30.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% 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 33%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17525
27525
37525
47327
57327
67228
77129
87030
96931
106733
116733
126634
136634
146535
156436
166436
176436
186436
196436
206436
216436
226436
236436
246436
256436
266436
276337
286337
296238
306238

Chance of precipitation in September

Any precipitation

Spokane Valley gets around 0.9 in of rain and snow over 4.4 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 15% and peaks near 18% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
110
210
310
410
511
611
711
812
913
1014
1114
1215
1316
1416
1516
1617
1717
1817
1917
2017
2118
2218
2318
2418
2518
2617
2717
2818
2918
3018

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 (%)
1982
2982
3982
4982
5982
6982
7982
8982
9991
10991
11991
12991
13991
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 5 mph in September.

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

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
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 5:12 AM to 5:53 AM, and sunset from 6:25 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:126:25
213.25:146:23
313.15:156:21
413.05:166:19
513.05:186:17
612.95:196:15
712.95:216:13
812.85:226:10
912.85:236:08
1012.75:256:06
1112.65:266:04
1212.65:286:02
1312.55:296:00
1412.55:305:58
1512.45:325:56
1612.35:335:53
1712.35:345:51
1812.25:365:49
1912.25:375:47
2012.15:395:45
2112.05:405:43
2212.05:425:41
2311.95:435:38
2411.95:445:36
2511.85:465:34
2611.75:475:32
2711.75:495:30
2811.65:505:28
2911.65:515:26
3011.55:535:24

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.72 kWh/m².

For context, solar energy here swings from a low near 1.06 kWh/m² to a high of 7.56 kWh/m² in July across the year — September's 4.72 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.6Bright
25.5Bright
35.5Bright
45.4Bright
55.3Bright
65.3Bright
75.2Bright
85.2Bright
95.1Bright
105.0Bright
115.0Bright
124.9Bright
134.8Bright
144.8Bright
154.7Bright
164.7Bright
174.6Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.3Bright
234.3Bright
244.2Bright
254.1Bright
264.1Bright
274.0Bright
284.0Moderate
293.9Moderate
303.8Moderate
Planning a trip in September

Is September a good time to visit Spokane Valley?

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

7.8
Sightseeing
1st-best month of the year
5.7
Beach & pool
3rd-best month of the year

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

What to pack for Spokane Valley in September

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

In September, Spokane Valley sees daytime highs around 73°F and nights near 49°F. Worth packing: light clothes and sun protection. About 4 days see rain.

light clothessun protection

UV index in Spokane Valley in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Spokane Valley peaks around July 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 17UV 8Dec 17UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5Moderate
May7High
Jun6High
Jul9Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Spokane Valley 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 Spokane Valley is worst in August — around 30 µg/m³ PM2.5 (moderate), about 4.9× the cleanest month (December, 6 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1828 µg/m³Dec 216 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar10Good
Apr11Good
May11Good
Jun10Good
Jul13Moderate
Aug30Moderate
Sep20Moderate
Oct11Good
Nov11Good
Dec6Good
Location & terrain

Where is Spokane Valley?

Spokane Valley sits at 47.7°N, 117.2°W, 2,018 ft above sea level, in United States. The nearest listed city is Opportunity, 1.9 mi away.

Topography around Spokane Valley

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

Within 2 miles, the terrain around Spokane Valley has only modest variations in elevation — a maximum elevation change of 456 ft around an average of 2,008 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,497 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,026 ft.

The land around Spokane Valley is covered by artificial surfaces (47%), trees (24%) and grassland (24%) within 2 miles, trees (43%) and grassland (28%) within 10 miles, and trees (52%), grassland (22%) and cropland (22%) within 50 miles.

2 miles
456 ft
10 miles
3,497 ft
50 miles
5,026 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Opportunity 1.9 mi · Spokane 8.7 mi · Post Falls 14 mi · Coeur d'Alene 21 mi · Pullman 65 mi · Moscow 66 mi · Lewiston 88 mi · Lewiston Orchards 90 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 Spokane Valley (47.6732°, -117.2394°, elevation 2,018 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).