Billings weather in September

In September, Billings sees average daytime highs of 74°F and overnight lows near 49°F, with 1.4 in of precipitation across 5.5 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 80°F in the first days to 68°F by the end. The sky is clear or mostly clear about 48% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Billings's 3rd-clearest and 9th-windiest month. For the whole year in context, see Billings's year-round climate.

Daytime high
74°
4th warmest
Overnight low
49°
9th coldest
Precipitation
1.4 in
5.5 wet days
Daylight
12 h 18 min
5:59 AM – 6:18 PM
Cloud cover
44%
3rd clearest
Wind
7 mph
9th windiest
Solar energy
4.8 kWh/m²
Travel score
7.6
out of 10

Billings is city in and county seat of Yellowstone County, Montana, United States.

Density
1,039/km²
people per km²
Founded
1877

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 80°F in the first days to 68°F by the end.

A typical September day in Billings reaches about 74°F in the afternoon and slips back to 49°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 59°F and 88°F. Set against its neighbours, September runs about 12°F cooler than August and about 15°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18254
28154
38054
48053
57953
67952
77852
87852
97751
107651
117650
127550
137549
147449
157449
167348
177348
187348
197247
207247
217147
227147
237146
247046
257046
266945
276945
286845
296844
306744

How September really feels in Billings

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.

Billings weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan35° / 18°0.95.75.88.90.0
Feb39° / 20°0.865.410.10.0
Mar49° / 27°1.27.14.311.62.1
Apr58° / 35°2.310.83.813.34.0
May67° / 45°2.610.70.614.76.0
Jun77° / 53°2.19015.56.9
Jul87° / 60°0.94.9015.25.5
Aug86° / 58°0.73.9013.96.1
Sep74° / 49°1.45.50.212.37.6
Oct59° / 38°1.87.22.210.75.0
Nov45° / 27°0.95.93.59.31.2
Dec36° / 20°0.85.45.28.50.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% 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 36%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17129
27129
37030
47030
56931
66832
76733
86634
96634
106535
116436
126436
136238
146238
156238
166238
176238
186337
196337
206337
216337
226337
236337
246337
256337
266337
276238
286238
296238
306139

Chance of precipitation in September

Any precipitationSnow

Billings gets around 1.4 in of rain and snow over 5.5 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 19% and peaks near 21% on the wettest days, and about 0 day brings snow.

0%10%20%30%151015202530
Rain chance (%)Snow chance (%)
1130
2140
3140
4150
5150
6160
7170
8170
9180
10190
11200
12200
13210
14210
15210
16211
17211
18211
19211
20211
21201
22201
23201
24202
25202
26202
27203
28203
29204
30204

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 (%)
1973
2973
3973
4982
5982
6982
7982
8982
9982
10982
11982
12982
13982
14982
15991
16991
17991
18991
19991
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 7 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 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
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 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 96 minutes over September. Sunrise moves from 5:40 AM to 6:17 AM, and sunset from 6:48 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:406:48
213.15:416:46
313.05:426:44
413.05:436:42
512.95:456:40
612.95:466:38
712.85:476:36
812.85:496:34
912.75:506:32
1012.65:516:30
1112.65:526:28
1212.55:546:26
1312.55:556:24
1412.45:566:22
1512.45:586:20
1612.35:596:18
1712.36:006:16
1812.26:016:14
1912.26:036:12
2012.16:046:10
2112.06:056:08
2212.06:076:06
2311.96:086:04
2411.96:096:02
2511.86:106:00
2611.86:125:58
2711.76:135:56
2811.76:145:54
2911.66:165:52
3011.56:175:50

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.8 kWh/m².

For context, solar energy here swings from a low near 1.63 kWh/m² to a high of 7.37 kWh/m² in July across the year — September's 4.8 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.7Bright
25.6Bright
35.5Bright
45.5Bright
55.4Bright
65.3Bright
75.3Bright
85.2Bright
95.2Bright
105.1Bright
115.0Bright
125.0Bright
134.9Bright
144.8Bright
154.8Bright
164.7Bright
174.7Bright
184.6Bright
194.6Bright
204.5Bright
214.5Bright
224.4Bright
234.4Bright
244.3Bright
254.3Bright
264.2Bright
274.2Bright
284.1Bright
294.0Bright
304.0Moderate
Planning a trip in September

Is September a good time to visit Billings?

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

7.6
Sightseeing
1st-best month of the year
5.8
Beach & pool
4th-best month of the year

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

What to pack for Billings in September

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

In September, Billings sees daytime highs around 74°F and nights near 49°F. Worth packing: light clothes and sun protection. About 6 days see rain.

light clothessun protection

UV index in Billings 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 Billings peaks around July 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 13UV 9Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5Moderate
May6High
Jun9Very high
Jul9Very high
Aug7High
Sep5High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Billings 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 Billings is worst in August — around 17 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodAug 1817 µg/m³Dec 157 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar13Moderate
Apr11Good
May11Good
Jun12Good
Jul13Moderate
Aug17Moderate
Sep14Moderate
Oct8Good
Nov8Good
Dec7Good
Location & terrain

Where is Billings?

Billings sits at 45.8°N, 108.5°W, 3,123 ft above sea level, in United States. The nearest listed city is Sheridan, 101 mi away.

Topography around Billings

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

Within 2 miles, the terrain around Billings has only modest variations in elevation — a maximum elevation change of 551 ft around an average of 3,196 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,096 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,050 ft.

The land around Billings is covered by artificial surfaces (38%), trees (28%) and grassland (25%) within 2 miles, grassland (69%) within 10 miles, and grassland (81%) within 50 miles.

2 miles
551 ft
10 miles
1,096 ft
50 miles
6,050 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Sheridan 101 mi · Bozeman 122 mi · Great Falls 178 mi · Helena 178 mi · Gillette 179 mi · Butte 194 mi · Rexburg 211 mi · Casper 229 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 Billings (45.7833°, -108.5007°, elevation 3,123 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).