Barstow Heights weather in September

In September, Barstow Heights sees average daytime highs of 89°F and overnight lows near 64°F, with 0.1 in of rain across 1 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 93°F in the first days to 85°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 Barstow Heights's 1st-clearest and 8th-windiest month. For the whole year in context, see Barstow Heights's year-round climate.

Daytime high
89°
4th warmest
Overnight low
64°
10th coldest
Rainfall
0.1 in
1 wet days
Daylight
12 h 12 min
5:36 AM – 5:49 PM
Cloud cover
14%
1st clearest
Wind
6 mph
8th windiest
Solar energy
6.43 kWh/m²
Travel score
5.6
out of 10

Barstow Heights is human settlement in San Bernardino County, California, United States of America.

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 93°F in the first days to 85°F by the end.

A typical September day in Barstow Heights reaches about 89°F in the afternoon and slips back to 64°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 80°F and 96°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19468
29368
39368
49367
59267
69267
79267
89166
99166
109166
119065
129065
139065
148964
158964
168964
178964
188863
198863
208863
218762
228762
238762
248662
258661
268661
278561
288560
298460
308460

How September really feels in Barstow Heights

Once humidity and wind are folded in, September averages 13 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
13
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.

Barstow Heights 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 daysDaylight (hours)Travel score
Jan57° / 39°0.83.69.94.9
Feb60° / 41°1.03.910.75.8
Mar67° / 45°0.62.711.77.5
Apr73° / 49°0.41.812.98.6
May81° / 57°0.10.813.88.2
Jun91° / 64°0.10.414.34.9
Jul96° / 70°0.3214.12.7
Aug96° / 70°0.21.213.33.0
Sep89° / 64°0.1112.25.6
Oct77° / 54°0.2111.18.8
Nov65° / 44°0.31.510.27.4
Dec56° / 38°0.82.99.74.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 87% of the time in September, the clearest month of the year.

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

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1928
2928
3928
4937
5937
6946
7946
8946
9946
10946
11955
12946
13946
14946
15946
16946
17946
18946
19946
20946
21946
22946
23946
24946
25937
26937
27937
28937
29937
30937

Chance of precipitation in September

Any precipitation

Barstow Heights gets around 0.1 in of rain over 1 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 3% and peaks near 5% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
15
25
35
45
55
65
75
84
94
104
113
123
133
143
152
162
172
182
192
202
212
222
232
242
252
262
272
282
292
302

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 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
19163
29163
39163
49253
59253
69253
79253
89442
99442
109442
119532
129631
139721
149721
159721
169721
179811
189811
199910
209910
219910
229910
239910
249910
259910
269910
279910
289910
299910
309910

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 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
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:25 AM to 5:47 AM, and sunset from 6:11 PM to 5:28 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:256:11
212.75:266:10
312.75:266:08
412.75:276:07
512.65:286:05
612.65:296:04
712.55:296:02
812.55:306:01
912.55:315:59
1012.45:325:58
1112.45:325:56
1212.45:335:55
1312.35:345:53
1412.35:355:52
1512.35:355:51
1612.25:365:49
1712.25:375:48
1812.15:385:46
1912.15:385:45
2012.15:395:43
2112.05:405:42
2212.05:415:40
2312.05:415:39
2411.95:425:37
2511.95:435:36
2611.85:445:34
2711.85:445:33
2811.85:455:31
2911.75:465:30
3011.75:475:28

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.43 kWh/m².

For context, solar energy here swings from a low near 3.13 kWh/m² to a high of 8.62 kWh/m² in June across the year — September's 6.43 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.9Intense
26.9Intense
36.8Intense
46.8Intense
56.8Intense
66.8Intense
76.7Intense
86.7Intense
96.7Intense
106.6Intense
116.6Intense
126.6Intense
136.5Intense
146.5Intense
156.5Intense
166.5Intense
176.4Intense
186.4Intense
196.3Intense
206.3Intense
216.3Intense
226.2Intense
236.2Intense
246.1Intense
256.1Intense
266.0Intense
276.0Bright
286.0Bright
295.9Bright
305.8Bright
Planning a trip in September

Is September a good time to visit Barstow Heights?

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

5.6
Sightseeing
7th-best month of the year
8.6
Beach & pool
2nd-best month of the year

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

What to pack for Barstow Heights in September

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

In September, Barstow Heights sees daytime highs around 89°F and nights near 64°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Barstow Heights in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Barstow Heights peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 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 17UV 3
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar5High
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Barstow Heights 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 Barstow Heights is worst in September — around 30 µg/m³ PM2.5 (moderate), about 5.3× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1427 µg/m³Dec 146 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb7Good
Mar9Good
Apr9Good
May9Good
Jun16Moderate
Jul12Good
Aug15Moderate
Sep30Moderate
Oct7Good
Nov6Good
Dec6Good
Location & terrain

Where is Barstow Heights?

Barstow Heights sits at 34.9°N, 117.1°W, 2,559 ft above sea level, in United States. The nearest listed city is Barstow, 2.5 mi away.

Topography around Barstow Heights

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

Within 2 miles, the terrain around Barstow Heights has significant variations in elevation — a maximum elevation change of 948 ft around an average of 2,523 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,077 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 8,855 ft.

The land around Barstow Heights is covered by bare terrain (82%) within 2 miles, bare terrain (89%) within 10 miles, and bare terrain (67%) within 50 miles.

2 miles
948 ft
10 miles
2,077 ft
50 miles
8,855 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrain
September weather nearby: Barstow 2.5 mi · Apple Valley 27 mi · Victorville 27 mi · Adelanto 28 mi · Hesperia 34 mi · Highland 52 mi · San Bernardino 54 mi · Rialto 56 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 Barstow Heights (34.8697°, -117.0562°, elevation 2,559 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).