Cheyenne weather in September

In September, Cheyenne sees average daytime highs of 73°F and overnight lows near 47°F, with 1.5 in of precipitation across 6 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 78°F in the first days to 67°F by the end. The sky is clear or mostly clear about 49% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Cheyenne's 1st-clearest and 10th-windiest month. For the whole year in context, see Cheyenne's year-round climate.

Daytime high
73°
4th warmest
Overnight low
47°
9th coldest
Precipitation
1.5 in
6 wet days
Daylight
12 h 18 min
5:46 AM – 6:02 PM
Cloud cover
42%
1st clearest
Wind
9 mph
10th windiest
Solar energy
5.31 kWh/m²
Travel score
7.5
out of 10

Cheyenne is capital city of the U.S. state of Wyoming and seat of Laramie County.

Density
1,021/km²
people per km²
Founded
1867

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 67°F by the end.

A typical September day in Cheyenne reaches about 73°F in the afternoon and slips back to 47°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 58°F and 84°F. Set against its neighbours, September runs about 8°F cooler than August and about 14°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17953
27853
37852
47852
57752
67751
77651
87650
97550
107549
117449
127449
137448
147348
157347
167247
177247
187146
197146
207145
217045
227045
236944
246944
256944
266843
276843
286742
296742
306642

How September really feels in Cheyenne

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.

Cheyenne weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 21°0.53.93.89.40.0
Feb40° / 21°0.74.84.810.40.1
Mar49° / 27°1.46.65.111.72.1
Apr55° / 32°2.4105.413.13.4
May64° / 42°3.012.31.514.35.3
Jun76° / 51°2.110.2014.96.8
Jul83° / 57°1.69.3014.76.3
Aug81° / 56°1.58.2013.66.9
Sep73° / 47°1.560.412.37.5
Oct59° / 36°1.56.92.710.95.1
Nov47° / 27°0.84.74.49.71.7
Dec38° / 21°0.74.24.59.10.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 30%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17327
27327
37228
47228
57129
67129
77129
87030
97030
107030
116931
126931
136931
146832
156832
166832
176931
186931
196931
207030
216931
226931
236931
247030
256931
266931
276931
286931
296931
306931

Chance of precipitation in September

Any precipitationSnow

Cheyenne gets around 1.5 in of rain and snow over 6 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 21% and peaks near 21% on the wettest days, and about 0 day brings snow.

0%10%20%30%151015202530
Rain chance (%)Snow chance (%)
1200
2200
3200
4200
5200
6211
7211
8211
9211
10211
11211
12211
13211
14211
15211
16212
17212
18212
19202
20202
21202
22202
23202
24202
25202
26203
27213
28213
29214
30214

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
9982
10991
11991
12991
13991
14991
15991
16991
17991
18991
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 9 mph in September.

Across September, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:30 AM to 6:00 AM, and sunset from 6:28 PM to 5:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:306:28
212.95:316:26
312.95:326:25
412.85:336:23
512.85:346:21
612.75:356:19
712.75:366:18
812.65:376:16
912.65:386:14
1012.65:396:12
1112.55:406:11
1212.55:416:09
1312.45:426:07
1412.45:436:05
1512.35:446:03
1612.35:466:02
1712.25:476:00
1812.25:485:58
1912.15:495:56
2012.15:505:55
2112.05:515:53
2212.05:525:51
2311.95:535:49
2411.95:545:47
2511.85:555:46
2611.85:565:44
2711.85:575:42
2811.75:585:40
2911.75:595:39
3011.66:005:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.31 kWh/m².

For context, solar energy here swings from a low near 2.29 kWh/m² to a high of 7.28 kWh/m² in June across the year — September's 5.31 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.0Bright
25.9Bright
35.9Bright
45.8Bright
55.8Bright
65.7Bright
75.7Bright
85.6Bright
95.6Bright
105.5Bright
115.5Bright
125.4Bright
135.4Bright
145.3Bright
155.3Bright
165.3Bright
175.2Bright
185.2Bright
195.1Bright
205.1Bright
215.0Bright
225.0Bright
234.9Bright
244.9Bright
254.8Bright
264.8Bright
274.7Bright
284.7Bright
294.6Bright
304.6Bright
Planning a trip in September

Is September a good time to visit Cheyenne?

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

7.5
Sightseeing
1st-best month of the year
5.4
Beach & pool
4th-best month of the year

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

What to pack for Cheyenne in September

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

In September, Cheyenne sees daytime highs around 73°F and nights near 47°F. Worth packing: light clothes and sun protection. About 6 days see rain.

light clothessun protection

UV index in Cheyenne in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cheyenne peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 13UV 11Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar7High
Apr6High
May8Very high
Jun10Extreme
Jul11Extreme
Aug9Very high
Sep7Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Cheyenne 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 Cheyenne is worst in September — around 15 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1415 µg/m³Nov 236 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar10Good
Apr9Good
May10Good
Jun10Good
Jul11Good
Aug14Moderate
Sep15Moderate
Oct13Moderate
Nov6Good
Dec6Good
Location & terrain

Where is Cheyenne?

Cheyenne sits at 41.1°N, 104.8°W, 6,089 ft above sea level, in United States. The nearest listed city is Fort Collins, 41 mi away.

Topography around Cheyenne

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

Within 2 miles, the terrain around Cheyenne has only modest variations in elevation — a maximum elevation change of 184 ft around an average of 6,099 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 984 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,801 ft.

The land around Cheyenne is covered by artificial surfaces (57%) and grassland (32%) within 2 miles, grassland (90%) within 10 miles, and grassland (83%) within 50 miles.

2 miles
184 ft
10 miles
984 ft
50 miles
5,801 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Fort Collins 41 mi · Laramie 42 mi · Windsor 46 mi · Greeley 50 mi · Loveland 53 mi · Evans 53 mi · Estes Park 64 mi · Longmont 69 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 Cheyenne (41.14°, -104.8203°, elevation 6,089 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).