Boulder City weather in September

In September, Boulder City sees average daytime highs of 95°F and overnight lows near 73°F, with 0.3 in of rain across 1.8 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 99°F in the first days to 90°F by the end. The sky is clear or mostly clear about 84% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Boulder City's 2nd-clearest and 7th-windiest month. For the whole year in context, see Boulder City's year-round climate.

Daytime high: 95°; 4th warmest
Overnight low: 73°; 9th coldest
Rainfall: 0.3 in; 1.8 wet days
Daylight: 12 h 12 min; 5:27 AM – 5:40 PM
Cloud cover: 17%; 2nd clearest
Wind: 5 mph; 7th windiest
Solar energy: 6.21 kWh/m²
Travel score: 3.4; out of 10

Boulder City is city in Clark County, Nevada, United States.

Density: 29/km²; people per km²
Founded: 1931

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

← August Boulder City year-round climate October →Best places to visit in September

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 99°F in the first days to 90°F by the end.

A typical September day in Boulder City reaches about 95°F in the afternoon and slips back to 73°F overnight — a 21°F spread between the day's warmth and the night's chill. On most days the high lands between 86°F and 102°F. Set against its neighbours, September runs about 8°F cooler than August and about 13°F warmer than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°F)	100	99	99	99	98	98	98	97	97	96	96	96	95	95	95	94	94	94	94	93	93	93	92	92	92	91	91	90	90	89
Avg low (°F)	79	78	78	78	77	77	76	76	76	75	75	74	74	74	73	73	73	72	72	72	71	71	71	70	70	69	69	69	68	68

	Avg high (°F)	Avg low (°F)
1	100	79
2	99	78
3	99	78
4	99	78
5	98	77
6	98	77
7	98	76
8	97	76
9	97	76
10	96	75
11	96	75
12	96	74
13	95	74
14	95	74
15	95	73
16	94	73
17	94	73
18	94	72
19	94	72
20	93	72
21	93	71
22	93	71
23	92	71
24	92	70
25	92	70
26	91	69
27	91	69
28	90	69
29	90	68
30	89	68

How September really feels in Boulder City

Once humidity and wind are folded in, September averages 29 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

heat index over the day's high

Days feeling ≤ 32°F

wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Boulder City weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Daylight (hours)	Travel score
Jan	58° / 41°	0.9	3.6	9.8	5.1
Feb	63° / 45°	1.2	4.4	10.6	6.5
Mar	71° / 51°	0.7	3.2	11.7	8.0
Apr	79° / 57°	0.3	1.6	12.9	8.3
May	89° / 66°	0.1	1.1	13.9	5.5
Jun	99° / 75°	0.1	0.5	14.4	1.8
Jul	104° / 82°	0.3	2.5	14.2	0.0
Aug	102° / 81°	0.4	3	13.4	0.6
Sep	95° / 73°	0.3	1.8	12.2	3.4
Oct	81° / 61°	0.4	1.8	11.1	7.8
Nov	67° / 49°	0.5	1.7	10.1	7.8
Dec	56° / 41°	0.8	3	9.6	4.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 84% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 7% of September, with mostly cloudy or overcast conditions the remaining 9%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	89	88	88	89	89	89	89	90	91	91	91	91	92	92	92	92	92	92	92	93	93	93	92	92	92	92	92	91	91	91
Cloudier (%)	11	12	12	11	11	11	11	10	9	9	9	9	8	8	8	8	8	8	8	7	7	7	8	8	8	8	8	9	9	9

	Clearer (%)	Cloudier (%)
1	89	11
2	88	12
3	88	12
4	89	11
5	89	11
6	89	11
7	89	11
8	90	10
9	91	9
10	91	9
11	91	9
12	91	9
13	92	8
14	92	8
15	92	8
16	92	8
17	92	8
18	92	8
19	92	8
20	93	7
21	93	7
22	93	7
23	92	8
24	92	8
25	92	8
26	92	8
27	92	8
28	91	9
29	91	9
30	91	9

Chance of precipitation in September

Any precipitation

Boulder City gets around 0.3 in of rain over 1.8 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 10% on the wettest days. The odds ease toward the end of the month.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	10	10	10	10	10	9	9	9	9	8	8	7	7	7	6	6	5	5	5	4	4	4	4	4	4	4	4	4	4	4

	Rain chance (%)
1	10
2	10
3	10
4	10
5	10
6	9
7	9
8	9
9	9
10	8
11	8
12	7
13	7
14	7
15	6
16	6
17	5
18	5
19	5
20	4
21	4
22	4
23	4
24	4
25	4
26	4
27	4
28	4
29	4
30	4

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 85% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	72	74	74	73	73	74	74	74	76	78	79	80	82	83	84	85	87	89	90	91	93	93	93	94	95	95	95	95	95	95
Comfortable (%)	17	16	16	16	16	15	15	15	14	13	12	11	10	9	9	8	7	6	6	5	4	4	4	3	3	3	3	3	3	3
Humid (%)	8	8	8	9	9	9	9	9	8	8	8	8	7	7	6	6	5	5	4	4	3	3	3	3	2	2	2	2	2	2
Muggy (%)	3	2	2	2	2	2	2	2	2	1	1	1	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	72	17	8	3
2	74	16	8	2
3	74	16	8	2
4	73	16	9	2
5	73	16	9	2
6	74	15	9	2
7	74	15	9	2
8	74	15	9	2
9	76	14	8	2
10	78	13	8	1
11	79	12	8	1
12	80	11	8	1
13	82	10	7	1
14	83	9	7	1
15	84	9	6	1
16	85	8	6	1
17	87	7	5	1
18	89	6	5	0
19	90	6	4	0
20	91	5	4	0
21	93	4	3	0
22	93	4	3	0
23	93	4	3	0
24	94	3	3	0
25	95	3	2	0
26	95	3	2	0
27	95	3	2	0
28	95	3	2	0
29	95	3	2	0
30	95	3	2	0

Wind in September

Winds average 5 mph in September.

Across September, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (mph)	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	4	4	4
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (mph)	Feels
1	5	calm
2	5	calm
3	5	calm
4	5	calm
5	5	calm
6	5	calm
7	5	calm
8	5	calm
9	5	calm
10	5	calm
11	5	calm
12	5	calm
13	5	calm
14	5	calm
15	5	calm
16	5	calm
17	5	calm
18	5	calm
19	5	calm
20	5	calm
21	5	calm
22	5	calm
23	5	calm
24	5	calm
25	5	calm
26	5	calm
27	5	calm
28	4	calm
29	4	calm
30	4	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 5:15 AM to 5:38 AM, and sunset from 6:03 PM to 5:19 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.8	12.8	12.7	12.7	12.6	12.6	12.6	12.5	12.5	12.5	12.4	12.4	12.3	12.3	12.3	12.2	12.2	12.1	12.1	12.1	12.0	12.0	12.0	11.9	11.9	11.8	11.8	11.8	11.7	11.7
Sunrise (AM)	5:15	5:16	5:17	5:17	5:18	5:19	5:20	5:21	5:21	5:22	5:23	5:24	5:25	5:25	5:26	5:27	5:28	5:29	5:29	5:30	5:31	5:32	5:33	5:33	5:34	5:35	5:36	5:37	5:37	5:38
Sunset (PM)	6:03	6:02	6:00	5:59	5:57	5:56	5:54	5:53	5:51	5:50	5:48	5:47	5:45	5:43	5:42	5:40	5:39	5:37	5:36	5:34	5:33	5:31	5:30	5:28	5:27	5:25	5:24	5:22	5:20	5:19

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.8	5:15	6:03
2	12.8	5:16	6:02
3	12.7	5:17	6:00
4	12.7	5:17	5:59
5	12.6	5:18	5:57
6	12.6	5:19	5:56
7	12.6	5:20	5:54
8	12.5	5:21	5:53
9	12.5	5:21	5:51
10	12.5	5:22	5:50
11	12.4	5:23	5:48
12	12.4	5:24	5:47
13	12.3	5:25	5:45
14	12.3	5:25	5:43
15	12.3	5:26	5:42
16	12.2	5:27	5:40
17	12.2	5:28	5:39
18	12.1	5:29	5:37
19	12.1	5:29	5:36
20	12.1	5:30	5:34
21	12.0	5:31	5:33
22	12.0	5:32	5:31
23	12.0	5:33	5:30
24	11.9	5:33	5:28
25	11.9	5:34	5:27
26	11.8	5:35	5:25
27	11.8	5:36	5:24
28	11.8	5:37	5:22
29	11.7	5:37	5:20
30	11.7	5:38	5:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.21 kWh/m².

For context, solar energy here swings from a low near 2.87 kWh/m² to a high of 8.53 kWh/m² in June across the year — September's 6.21 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	6.7	6.6	6.6	6.5	6.5	6.5	6.5	6.4	6.4	6.4	6.4	6.3	6.3	6.3	6.2	6.2	6.2	6.2	6.1	6.1	6.0	6.0	6.0	5.9	5.9	5.8	5.8	5.7	5.7	5.6
Level	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	6.7	Intense
2	6.6	Intense
3	6.6	Intense
4	6.5	Intense
5	6.5	Intense
6	6.5	Intense
7	6.5	Intense
8	6.4	Intense
9	6.4	Intense
10	6.4	Intense
11	6.4	Intense
12	6.3	Intense
13	6.3	Intense
14	6.3	Intense
15	6.2	Intense
16	6.2	Intense
17	6.2	Intense
18	6.2	Intense
19	6.1	Intense
20	6.1	Intense
21	6.0	Intense
22	6.0	Bright
23	6.0	Bright
24	5.9	Bright
25	5.9	Bright
26	5.8	Bright
27	5.8	Bright
28	5.7	Bright
29	5.7	Bright
30	5.6	Bright

Planning a trip in September

Is September a good time to visit Boulder City?

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

3.4

Sightseeing

9th-best month of the year

6.9

Beach & pool

4th-best month of the year

September is a weaker month for outdoor sightseeing in Boulder City. The water and warmth also suit a beach or pool day.

What to pack for Boulder City in September

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

In September, Boulder City sees daytime highs around 95°F and nights near 73°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Boulder City in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Boulder City peaks around June 22 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	3	4	5	6	8	11	10	10	8	6	3	2
Level	Moderate	Moderate	Moderate	High	Very high	Extreme	Extreme	Very high	Very high	High	Moderate	Moderate

	UV index (midday)	Level
Jan	3	Moderate
Feb	4	Moderate
Mar	5	Moderate
Apr	6	High
May	8	Very high
Jun	11	Extreme
Jul	10	Extreme
Aug	10	Very high
Sep	8	Very high
Oct	6	High
Nov	3	Moderate
Dec	2	Moderate

Location & terrain

Where is Boulder City?

Boulder City sits at 36.0°N, 114.8°W, 2,510 ft above sea level, in United States. The nearest listed city is Henderson, 9.3 mi away.

Topography around Boulder City

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

Within 2 miles, the terrain around Boulder City has significant variations in elevation — a maximum elevation change of 1,634 ft around an average of 2,431 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,455 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 10,315 ft.

The land around Boulder City is covered by bare terrain (55%) and artificial surfaces (27%) within 2 miles, bare terrain (68%) within 10 miles, and bare terrain (59%) and shrubs (26%) within 50 miles.

2 miles

1,634 ft

bare terrain 55%

10 miles

3,455 ft

bare terrain 68%

50 miles

10,315 ft

bare terrain 59%

treesshrubsgrasslandartificial surfacesbare terrainwater

← August Boulder City year-round climate October →Best places to visit in September

September weather nearby: Henderson 9.3 mi · Whitney 14 mi · Winchester 19 mi · Paradise 19 mi · Sunrise Manor 21 mi · Las Vegas 22 mi · North Las Vegas 22 mi · Enterprise 23 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

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 Boulder City (35.9786°, -114.8325°, elevation 2,510 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°F)	Avg low (°F)
1	100	79
2	99	78
3	99	78
4	99	78
5	98	77
6	98	77
7	98	76
8	97	76
9	97	76
10	96	75
11	96	75
12	96	74
13	95	74
14	95	74
15	95	73
16	94	73
17	94	73
18	94	72
19	94	72
20	93	72
21	93	71
22	93	71
23	92	71
24	92	70
25	92	70
26	91	69
27	91	69
28	90	69
29	90	68
30	89	68

	Clearer (%)	Cloudier (%)
1	89	11
2	88	12
3	88	12
4	89	11
5	89	11
6	89	11
7	89	11
8	90	10
9	91	9
10	91	9
11	91	9
12	91	9
13	92	8
14	92	8
15	92	8
16	92	8
17	92	8
18	92	8
19	92	8
20	93	7
21	93	7
22	93	7
23	92	8
24	92	8
25	92	8
26	92	8
27	92	8
28	91	9
29	91	9
30	91	9

	Rain chance (%)
1	10
2	10
3	10
4	10
5	10
6	9
7	9
8	9
9	9
10	8
11	8
12	7
13	7
14	7
15	6
16	6
17	5
18	5
19	5
20	4
21	4
22	4
23	4
24	4
25	4
26	4
27	4
28	4
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	72	17	8	3
2	74	16	8	2
3	74	16	8	2
4	73	16	9	2
5	73	16	9	2
6	74	15	9	2
7	74	15	9	2
8	74	15	9	2
9	76	14	8	2
10	78	13	8	1
11	79	12	8	1
12	80	11	8	1
13	82	10	7	1
14	83	9	7	1
15	84	9	6	1
16	85	8	6	1
17	87	7	5	1
18	89	6	5	0
19	90	6	4	0
20	91	5	4	0
21	93	4	3	0
22	93	4	3	0
23	93	4	3	0
24	94	3	3	0
25	95	3	2	0
26	95	3	2	0
27	95	3	2	0
28	95	3	2	0
29	95	3	2	0
30	95	3	2	0

	Avg high (°F)	Avg low (°F)
1	100	79
2	99	78
3	99	78
4	99	78
5	98	77
6	98	77
7	98	76
8	97	76
9	97	76
10	96	75
11	96	75
12	96	74
13	95	74
14	95	74
15	95	73
16	94	73
17	94	73
18	94	72
19	94	72
20	93	72
21	93	71
22	93	71
23	92	71
24	92	70
25	92	70
26	91	69
27	91	69
28	90	69
29	90	68
30	89	68

	Clearer (%)	Cloudier (%)
1	89	11
2	88	12
3	88	12
4	89	11
5	89	11
6	89	11
7	89	11
8	90	10
9	91	9
10	91	9
11	91	9
12	91	9
13	92	8
14	92	8
15	92	8
16	92	8
17	92	8
18	92	8
19	92	8
20	93	7
21	93	7
22	93	7
23	92	8
24	92	8
25	92	8
26	92	8
27	92	8
28	91	9
29	91	9
30	91	9

	Rain chance (%)
1	10
2	10
3	10
4	10
5	10
6	9
7	9
8	9
9	9
10	8
11	8
12	7
13	7
14	7
15	6
16	6
17	5
18	5
19	5
20	4
21	4
22	4
23	4
24	4
25	4
26	4
27	4
28	4
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	72	17	8	3
2	74	16	8	2
3	74	16	8	2
4	73	16	9	2
5	73	16	9	2
6	74	15	9	2
7	74	15	9	2
8	74	15	9	2
9	76	14	8	2
10	78	13	8	1
11	79	12	8	1
12	80	11	8	1
13	82	10	7	1
14	83	9	7	1
15	84	9	6	1
16	85	8	6	1
17	87	7	5	1
18	89	6	5	0
19	90	6	4	0
20	91	5	4	0
21	93	4	3	0
22	93	4	3	0
23	93	4	3	0
24	94	3	3	0
25	95	3	2	0
26	95	3	2	0
27	95	3	2	0
28	95	3	2	0
29	95	3	2	0
30	95	3	2	0

	Avg high (°F)	Avg low (°F)
1	100	79
2	99	78
3	99	78
4	99	78
5	98	77
6	98	77
7	98	76
8	97	76
9	97	76
10	96	75
11	96	75
12	96	74
13	95	74
14	95	74
15	95	73
16	94	73
17	94	73
18	94	72
19	94	72
20	93	72
21	93	71
22	93	71
23	92	71
24	92	70
25	92	70
26	91	69
27	91	69
28	90	69
29	90	68
30	89	68

	Clearer (%)	Cloudier (%)
1	89	11
2	88	12
3	88	12
4	89	11
5	89	11
6	89	11
7	89	11
8	90	10
9	91	9
10	91	9
11	91	9
12	91	9
13	92	8
14	92	8
15	92	8
16	92	8
17	92	8
18	92	8
19	92	8
20	93	7
21	93	7
22	93	7
23	92	8
24	92	8
25	92	8
26	92	8
27	92	8
28	91	9
29	91	9
30	91	9

	Rain chance (%)
1	10
2	10
3	10
4	10
5	10
6	9
7	9
8	9
9	9
10	8
11	8
12	7
13	7
14	7
15	6
16	6
17	5
18	5
19	5
20	4
21	4
22	4
23	4
24	4
25	4
26	4
27	4
28	4
29	4
30	4

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	72	17	8	3
2	74	16	8	2
3	74	16	8	2
4	73	16	9	2
5	73	16	9	2
6	74	15	9	2
7	74	15	9	2
8	74	15	9	2
9	76	14	8	2
10	78	13	8	1
11	79	12	8	1
12	80	11	8	1
13	82	10	7	1
14	83	9	7	1
15	84	9	6	1
16	85	8	6	1
17	87	7	5	1
18	89	6	5	0
19	90	6	4	0
20	91	5	4	0
21	93	4	3	0
22	93	4	3	0
23	93	4	3	0
24	94	3	3	0
25	95	3	2	0
26	95	3	2	0
27	95	3	2	0
28	95	3	2	0
29	95	3	2	0
30	95	3	2	0