San Clemente weather in September

In September, San Clemente sees average daytime highs of 17°C and overnight lows near 7°C, with 73 mm of rain across 6.8 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 16°C in the first days to 18°C by the end. The sky is clear or mostly clear about 40% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 12 min at the start of September to 12 h 18 min by month's end. Set against the rest of the year, September is San Clemente's 8th-clearest and 5th-windiest month. For the whole year in context, see San Clemente's year-round climate.

Daytime high
17°
8th warmest
Overnight low
4th coldest
Rainfall
73 mm
6.8 wet days
Daylight
11 h 48 min
7:47 AM – 7:34 PM
Cloud cover
52%
8th clearest
Wind
8 km/h
5th windiest
Solar energy
4.72 kWh/m²
Travel score
6.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 16°C in the first days to 18°C by the end.

A typical September day in San Clemente reaches about 17°C in the afternoon and slips back to 7°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 21°C. Set against its neighbours, September runs about 2°C warmer than August and about 3°C cooler than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
1166
2166
3166
4166
5166
6166
7166
8176
9176
10176
11176
12176
13176
14176
15176
16177
17177
18187
19187
20187
21187
22187
23187
24187
25187
26187
27187
28187
29187
30187

San Clemente weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 14°5114.18.0
Feb28° / 13°80.913.38.5
Mar25° / 12°151.612.38.8
Apr20° / 544.411.17.5
May16° / 1448.410.25.3
Jun14° / 221129.63.7
Jul13° / 16010.29.83.8
Aug15° / 1319.310.74.6
Sep17° / 736.811.86.0
Oct20° / 475.312.97.2
Nov24° / 10°192.413.98.6
Dec27° / 12°171.714.48.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 48%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24753
34852
44951
55050
65050
75248
85347
95347
105347
115347
125446
135545
145545
155545
165446
175446
185446
195347
205347
215248
225248
235248
245248
255149
265149
275248
285248
295248
305347

Chance of precipitation in September

Any precipitation

San Clemente gets around 73 mm of rain over 6.8 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 23% and peaks near 29% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
129
229
328
427
527
626
726
825
925
1025
1124
1224
1324
1423
1523
1622
1722
1822
1921
2021
2121
2221
2321
2420
2520
2620
2720
2819
2919
3019

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 (%)
11000
21000
31000
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
161000
171000
181000
191000
201000
211000
221000
231000
241000
25991
26991
27991
28991
29991
30991

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 12 min at the start of September to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over September. Sunrise moves from 8:09 AM to 7:26 AM, and sunset from 7:22 PM to 7:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.28:097:22
211.28:087:23
311.38:067:24
411.38:057:24
511.48:037:25
611.48:027:26
711.48:007:27
811.57:597:27
911.57:577:28
1011.67:567:29
1111.67:547:30
1211.67:537:31
1311.77:517:31
1411.77:507:32
1511.77:487:33
1611.87:477:34
1711.87:457:34
1811.97:447:35
1911.97:427:36
2011.97:417:37
2112.07:397:38
2212.07:387:38
2312.07:367:39
2412.17:357:40
2512.17:337:41
2612.27:327:42
2712.27:307:42
2812.27:297:43
2912.37:277:44
3012.37:267:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.72 kWh/m².

For context, solar energy here swings from a low near 2.04 kWh/m² to a high of 8.75 kWh/m² in January across the year — September's 4.72 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
13.9Moderate
23.9Moderate
34.0Moderate
44.0Bright
54.1Bright
64.2Bright
74.2Bright
84.3Bright
94.3Bright
104.4Bright
114.5Bright
124.5Bright
134.6Bright
144.7Bright
154.7Bright
164.8Bright
174.8Bright
184.9Bright
194.9Bright
205.0Bright
215.0Bright
225.1Bright
235.1Bright
245.2Bright
255.2Bright
265.3Bright
275.3Bright
285.3Bright
295.4Bright
305.4Bright
Planning a trip in September

Hazard calendar for San Clemente

In seasonPeak

None of San Clemente's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

San Clemente's rainy season runs May–August, when most of the year's rain falls.

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

Is September a good time to visit San Clemente?

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

6.0
Sightseeing
8th-best month of the year
1.6
Beach & pool
8th-best month of the year

September is a reasonable time to visit San Clemente for sightseeing.

What to pack for San Clemente in September

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

In September, San Clemente sees daytime highs around 17°C and nights near 7°C. Worth packing: a warm layer and sun protection. About 7 days see rain.

a warm layersun protection

UV index in San Clemente in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Clemente peaks around January 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateVery highExtremeJan 15UV 13Jun 15UV 2
UV index (midday)Level
Jan13Extreme
Feb12Extreme
Mar9Very high
Apr5High
May3Moderate
Jun2Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct8Very high
Nov11Extreme
Dec12Extreme

Air quality in San Clemente 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 San Clemente is worst in February — around 26 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateFeb 1425 µg/m³Dec 1412 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb26Moderate
Mar16Moderate
Apr19Moderate
May25Moderate
Jun21Moderate
Jul22Moderate
Aug21Moderate
Sep20Moderate
Oct16Moderate
Nov15Moderate
Dec12Good
Location & terrain

Where is San Clemente?

San Clemente sits at 35.5°S, 71.5°W, 214 m above sea level, in Chile. The nearest listed city is Colbún, 19 km away.

Topography around San Clemente

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Clemente.

Within 3 km, the terrain around San Clemente has only modest variations in elevation — a maximum elevation change of 55 m around an average of 204 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 596 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,923 m.

The land around San Clemente is covered by cropland (63%) within 3 km, cropland (45%), trees (25%) and grassland (22%) within 16 km, and trees (38%) and grassland (33%) within 80 km.

3 km
55 m
16 km
596 m
80 km
3,923 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Colbún 19 km · Talca 19 km · San Javier 23 km · Linares 36 km · Molina 51 km · Longaví 51 km · Sagrada Familia 61 km · Curicó 66 km

Chile travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F / L
220 V · 50 Hz
Prices
≈ 48% of US
price level, 2025
GDP per capita
$17,995
2025
Happiness
6.3 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
6.3
per 100k, 2023
Road deaths
14.9
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 517
Religion
Catholic 57%none 26%Evangelical or Protestant 16%other Christians and traditions related to Christ 1%

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 San Clemente (-35.5378°, -71.487°, elevation 214 m), 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).