Twentynine Palms weather in September

In September, Twentynine Palms sees average daytime highs of 93°F and overnight lows near 69°F, with 0.2 in of rain across 1.5 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 97°F in the first days to 89°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 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Twentynine Palms's 2nd-clearest and 12th-windiest month. For the whole year in context, see Twentynine Palms's year-round climate.

Daytime high
93°
4th warmest
Overnight low
69°
9th coldest
Rainfall
0.2 in
1.5 wet days
Daylight
12 h 12 min
5:32 AM – 5:45 PM
Cloud cover
14%
2nd clearest
Wind
5 mph
12th windiest
Solar energy
6.42 kWh/m²
Travel score
4.1
out of 10

Twentynine Palms is city in San Bernardino County, California, United States.

Density
170/km²
people per km²
Founded
1920

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 97°F in the first days to 89°F by the end.

A typical September day in Twentynine Palms reaches about 93°F in the afternoon and slips back to 69°F overnight — a 23°F spread between the day's warmth and the night's chill. On most days the high lands between 85°F and 99°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)
19774
29774
39774
49673
59673
69673
79673
89572
99572
109471
119471
129471
139470
149370
159370
169369
179269
189269
199268
209268
219168
229167
239167
249067
259066
269066
278966
288965
298865
308864

How September really feels in Twentynine Palms

Once humidity and wind are folded in, September averages 26 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
26
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.

Twentynine Palms weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan61° / 43°0.62.6106.2
Feb64° / 45°0.8310.77.2
Mar71° / 49°0.42.111.78.3
Apr78° / 54°0.21.212.88.7
May87° / 62°0.10.613.86.4
Jun96° / 70°0.00.214.23.0
Jul101° / 77°0.32.4141.2
Aug100° / 76°0.42.413.31.6
Sep93° / 69°0.21.512.24.1
Oct81° / 59°0.30.911.18.2
Nov68° / 48°0.20.910.28.2
Dec59° / 42°0.62.29.85.8

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 7% of September, with mostly cloudy or overcast conditions the remaining 6%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1928
2928
3928
4928
5928
6937
7946
8946
9946
10946
11946
12955
13955
14955
15955
16955
17946
18946
19946
20946
21946
22946
23937
24937
25937
26937
27937
28937
29937
30937

Chance of precipitation in September

Any precipitation

Twentynine Palms gets around 0.2 in of rain over 1.5 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 8% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
18
28
38
48
58
68
77
87
97
106
116
126
135
145
154
164
174
184
194
203
213
223
233
243
253
263
273
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 89% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1801262
2801262
3811261
4811261
5821251
6821251
7831151
8841150
9861040
10861040
1187940
1288930
1389830
1490730
1590730
1691630
1793520
1893520
1993520
2094420
2194420
2294420
2394420
2494420
2594420
2695320
2795320
2895320
2995320
3096310

Wind in September

Winds average 5 mph in September, the calmest month.

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 42 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 60 minutes over September. Sunrise moves from 5:22 AM to 5:43 AM, and sunset from 6:06 PM to 5:25 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:226:06
212.75:226:05
312.75:236:04
412.65:246:02
512.65:246:01
612.65:255:59
712.55:265:58
812.55:275:56
912.55:275:55
1012.45:285:54
1112.45:295:52
1212.45:295:51
1312.35:305:49
1412.35:315:48
1512.25:325:46
1612.25:325:45
1712.25:335:43
1812.15:345:42
1912.15:345:40
2012.15:355:39
2112.05:365:38
2212.05:375:36
2312.05:375:35
2411.95:385:33
2511.95:395:32
2611.85:405:30
2711.85:405:29
2811.85:415:27
2911.75:425:26
3011.75:435:25

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.42 kWh/m².

For context, solar energy here swings from a low near 3.18 kWh/m² to a high of 8.64 kWh/m² in June across the year — September's 6.42 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.8Intense
26.8Intense
36.8Intense
46.8Intense
56.7Intense
66.7Intense
76.7Intense
86.7Intense
96.6Intense
106.6Intense
116.6Intense
126.6Intense
136.5Intense
146.5Intense
156.5Intense
166.4Intense
176.4Intense
186.4Intense
196.3Intense
206.3Intense
216.3Intense
226.2Intense
236.2Intense
246.2Intense
256.1Intense
266.1Intense
276.0Intense
286.0Bright
295.9Bright
305.9Bright
Planning a trip in September

Is September a good time to visit Twentynine Palms?

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

4.1
Sightseeing
9th-best month of the year
7.6
Beach & pool
4th-best month of the year

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

What to pack for Twentynine Palms in September

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

In September, Twentynine Palms sees daytime highs around 93°F and nights near 69°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Twentynine Palms 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 Twentynine Palms 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
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May9Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep8Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Twentynine Palms 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 Twentynine Palms is worst in September — around 20 µg/m³ PM2.5 (moderate), about 4.6× the cleanest month (December, 4 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodSep 1418 µg/m³Dec 154 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar8Good
Apr8Good
May8Good
Jun14Moderate
Jul10Good
Aug11Good
Sep20Moderate
Oct6Good
Nov5Good
Dec4Good
Location & terrain

Where is Twentynine Palms?

Twentynine Palms sits at 34.1°N, 116.1°W, 1,988 ft above sea level, in United States. The nearest listed city is Yucca Valley, 22 mi away.

Topography around Twentynine Palms

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

Within 2 miles, the terrain around Twentynine Palms has significant variations in elevation — a maximum elevation change of 1,588 ft around an average of 2,073 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 4,209 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 11,650 ft.

The land around Twentynine Palms is covered by bare terrain (75%) and artificial surfaces (21%) within 2 miles, bare terrain (79%) within 10 miles, and bare terrain (73%) within 50 miles.

2 miles
1,588 ft
10 miles
4,209 ft
50 miles
11,650 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Yucca Valley 22 mi · Desert Hot Springs 29 mi · Indio 30 mi · Coachella 32 mi · Palm Desert 34 mi · Cathedral City 34 mi · Rancho Mirage 34 mi · Palm Springs 35 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 Twentynine Palms (34.1356°, -116.0542°, elevation 1,988 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).