Adelanto weather in September

In September, Adelanto sees average daytime highs of 85°F and overnight lows near 62°F, with 0.3 in of rain across 1.6 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 89°F in the first days to 82°F by the end. The sky is clear or mostly clear about 87% 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 Adelanto's 2nd-clearest and 10th-windiest month. For the whole year in context, see Adelanto's year-round climate.

Daytime high
85°
4th warmest
Overnight low
62°
10th coldest
Rainfall
0.3 in
1.6 wet days
Daylight
12 h 12 min
5:38 AM – 5:50 PM
Cloud cover
15%
2nd clearest
Wind
5 mph
10th windiest
Solar energy
6.39 kWh/m²
Travel score
6.8
out of 10

Adelanto is city in San Bernardino County, California, United States.

Density
229/km²
people per km²
Founded
1915

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 89°F in the first days to 82°F by the end.

A typical September day in Adelanto reaches about 85°F in the afternoon and slips back to 62°F overnight — a 23°F spread between the day's warmth and the night's chill. On most days the high lands between 76°F and 93°F. Set against its neighbours, September runs about 6°F cooler than August and about 11°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19066
28965
38965
48965
58965
68865
78864
88864
98764
108764
118763
128763
138663
148662
158662
168562
178562
188561
198561
208461
218461
228461
238360
248360
258360
268360
278259
288259
298159
308158

How September really feels in Adelanto

Once humidity and wind are folded in, September averages 1 day 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
1
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

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

Adelanto weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan55° / 39°1.95.31.59.94.1
Feb57° / 40°2.361.910.74.6
Mar62° / 43°1.45.51.111.76.3
Apr69° / 47°0.73.40.612.87.8
May77° / 53°0.32.1013.88.7
Jun86° / 60°0.10.8014.36.8
Jul92° / 66°0.43.1014.14.4
Aug92° / 67°0.32.6013.34.5
Sep85° / 62°0.31.6012.26.8
Oct75° / 54°0.41.8011.18.8
Nov63° / 44°0.62.70.410.26.9
Dec54° / 38°1.54.319.74.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 87% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 6% of September, with mostly cloudy or overcast conditions the remaining 7%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1928
2928
3928
4928
5937
6937
7937
8946
9946
10946
11946
12946
13946
14946
15946
16946
17946
18946
19946
20928
21928
22928
23928
24928
25928
26928
27928
28928
29919
30919

Chance of precipitation in September

Any precipitation

Adelanto gets around 0.3 in of rain over 1.6 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 5% and peaks near 9% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
19
29
39
49
59
68
78
87
97
106
115
125
134
144
154
163
173
183
193
203
213
223
233
243
253
264
274
284
294
304

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 95% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
188102
28992
38992
48992
59082
69082
79172
89271
99361
109451
119451
129541
139631
149631
159631
169721
179721
189721
199721
209820
219820
229820
239820
249820
259820
269820
279820
289820
299820
309910

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 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 5:27 AM to 5:48 AM, and sunset from 6:12 PM to 5:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:276:12
212.75:276:11
312.75:286:09
412.75:296:08
512.65:296:06
612.65:306:05
712.55:316:04
812.55:326:02
912.55:326:01
1012.45:335:59
1112.45:345:58
1212.45:355:56
1312.35:355:55
1412.35:365:53
1512.35:375:52
1612.25:385:50
1712.25:385:49
1812.15:395:47
1912.15:405:46
2012.15:415:44
2112.05:415:43
2212.05:425:41
2312.05:435:40
2411.95:445:39
2511.95:445:37
2611.85:455:36
2711.85:465:34
2811.85:475:33
2911.75:475:31
3011.75:485:30

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.39 kWh/m².

For context, solar energy here swings from a low near 3.07 kWh/m² to a high of 8.49 kWh/m² in June across the year — September's 6.39 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.9Intense
26.9Intense
36.8Intense
46.8Intense
56.8Intense
66.7Intense
76.7Intense
86.7Intense
96.6Intense
106.6Intense
116.6Intense
126.5Intense
136.5Intense
146.5Intense
156.4Intense
166.4Intense
176.4Intense
186.3Intense
196.3Intense
206.2Intense
216.2Intense
226.2Intense
236.1Intense
246.1Intense
256.0Intense
266.0Bright
275.9Bright
285.9Bright
295.8Bright
305.8Bright
Planning a trip in September

Is September a good time to visit Adelanto?

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

6.8
Sightseeing
5th-best month of the year
8.8
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Adelanto for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Adelanto in September

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

In September, Adelanto sees daytime highs around 85°F and nights near 62°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Adelanto 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 Adelanto peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 11Dec 15UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5High
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Adelanto 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 Adelanto is worst in September — around 39 µg/m³ PM2.5 (poor), about 3.2× the cleanest month (May, 12 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateModerateSep 1537 µg/m³May 1612 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb15Moderate
Mar16Moderate
Apr14Moderate
May12Moderate
Jun15Moderate
Jul18Moderate
Aug22Moderate
Sep39Poor
Oct15Moderate
Nov17Moderate
Dec14Moderate
Location & terrain

Where is Adelanto?

Adelanto sits at 34.6°N, 117.4°W, 2,871 ft above sea level, in United States. The nearest listed city is Victorville, 7.5 mi away.

Topography around Adelanto

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

Within 2 miles, the terrain around Adelanto has only modest variations in elevation — a maximum elevation change of 157 ft around an average of 2,874 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,008 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 11,230 ft.

The land around Adelanto is covered by grassland (39%) and bare terrain (39%) within 2 miles, bare terrain (47%) and grassland (28%) within 10 miles, and bare terrain (39%), grassland (21%) and shrubs (20%) within 50 miles.

2 miles
157 ft
10 miles
2,008 ft
50 miles
11,230 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrain
September weather nearby: Victorville 7.5 mi · Hesperia 12 mi · Apple Valley 14 mi · Barstow Heights 28 mi · Barstow 31 mi · Rialto 33 mi · Highland 34 mi · San Bernardino 34 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 Adelanto (34.5828°, -117.4092°, elevation 2,871 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).