Constitución weather in September

In September, Constitución sees average daytime highs of 13°C and overnight lows near 10°C, with 49 mm of rain across 5.1 wet days and about 11.8 hours of daylight. It is the 9th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 13°C through the month. The sky is clear or mostly clear about 45% 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 Constitución's 8th-clearest and 7th-windiest month. For the whole year in context, see Constitución's year-round climate.

Daytime high
13°
9th warmest
Overnight low
10°
3rd coldest
Rainfall
49 mm
5.1 wet days
Daylight
11 h 48 min
7:51 AM – 7:37 PM
Cloud cover
47%
8th clearest
Wind
17 km/h
7th windiest
Solar energy
5.02 kWh/m²
Travel score
4.2
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 13°C through the month.

A typical September day in Constitución reaches about 13°C in the afternoon and slips back to 10°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 15°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

10°13°15°151015202530
Avg high (°C)Avg low (°C)
11310
21310
31310
41310
51310
61310
71310
81310
91310
101310
111310
121310
131310
141310
151310
161310
171310
181310
191310
201310
211310
221310
231310
241310
251310
261310
271310
281310
291311
301411

Constitución weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan18° / 15°20.514.18.0
Feb18° / 15°50.713.38.0
Mar18° / 14°91.212.37.5
Apr16° / 13°313.611.15.9
May14° / 11°1227.710.24.4
Jun13° / 11°169119.73.6
Jul12° / 10°1218.99.93.5
Aug13° / 10°988.410.73.6
Sep13° / 10°495.111.84.2
Oct14° / 11°284.312.95.0
Nov16° / 12°111.413.96.2
Dec17° / 14°6114.37.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 45% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25248
35446
45446
55644
65644
75743
85842
95842
105941
115941
126040
136040
146040
156040
166139
176139
186139
196040
206040
215941
225941
235941
245941
255941
265941
275842
285941
295941
305941

Chance of precipitation in September

Any precipitation

Constitución gets around 49 mm of rain over 5.1 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 18% and peaks near 24% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
124
223
322
422
521
620
719
819
918
1018
1118
1218
1317
1417
1517
1616
1716
1816
1916
2016
2116
2216
2316
2416
2516
2616
2716
2816
2916
3016

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100

Wind in September

Winds average 17 km/h in September.

Across September, daily wind ranges from about 17 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
717light breeze
817light breeze
917light breeze
1017light breeze
1117light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze

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 8:13 AM to 7:30 AM, and sunset from 7:26 PM to 7:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.28:137:26
211.38:117:27
311.38:107:27
411.38:087:28
511.48:077:29
611.48:067:30
711.48:047:31
811.58:037:31
911.58:017:32
1011.68:007:33
1111.67:587:34
1211.67:577:34
1311.77:557:35
1411.77:547:36
1511.77:527:37
1611.87:517:37
1711.87:497:38
1811.97:487:39
1911.97:467:40
2011.97:447:40
2112.07:437:41
2212.07:417:42
2312.07:407:43
2412.17:387:44
2512.17:377:44
2612.27:357:45
2712.27:347:46
2812.27:327:47
2912.37:317:48
3012.37:307:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.02 kWh/m².

For context, solar energy here swings from a low near 2.16 kWh/m² to a high of 8.8 kWh/m² in December across the year — September's 5.02 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.1Bright
24.2Bright
34.3Bright
44.3Bright
54.4Bright
64.4Bright
74.5Bright
84.6Bright
94.6Bright
104.7Bright
114.8Bright
124.8Bright
134.9Bright
144.9Bright
155.0Bright
165.0Bright
175.1Bright
185.2Bright
195.2Bright
205.3Bright
215.3Bright
225.4Bright
235.4Bright
245.5Bright
255.5Bright
265.6Bright
275.6Bright
285.7Bright
295.7Bright
305.8Bright
Planning a trip in September

Hazard calendar for Constitución

In seasonPeak

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

Constitución'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 Constitución?

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

4.2
Sightseeing
9th-best month of the year
0.0
Beach & pool
9th-best month of the year

September is a reasonable time to visit Constitución for sightseeing.

What to pack for Constitución in September

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

In September, Constitución sees daytime highs around 13°C and nights near 10°C. Worth packing: a warm layer and sun protection. About 5 days see rain.

a warm layersun protection

Sea temperature near Constitución in September

The nearest coast averages about 12°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 20 km away) is warmest in February at about 15°C and coldest in August near 12°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

10°12°14°16°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan15Bracing
Feb15Cool
Mar15Bracing
Apr14Bracing
May14Bracing
Jun13Bracing
Jul13Bracing
Aug12Bracing
Sep12Bracing
Oct13Bracing
Nov13Bracing
Dec14Bracing

UV index in Constitución 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 Constitución peaks around January 16 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 highModerateHighVery highExtremeJan 16UV 13Jun 15UV 2
UV index (midday)Level
Jan13Extreme
Feb11Extreme
Mar9Very high
Apr5High
May3Moderate
Jun2Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct9Very high
Nov11Extreme
Dec12Extreme
Location & terrain

Where is Constitución?

Constitución sits at 35.3°S, 72.4°W, 19 m above sea level, in Chile. The nearest listed city is San Javier, 68 km away.

Topography around Constitución

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

Within 3 km, the terrain around Constitución has significant variations in elevation — a maximum elevation change of 265 m around an average of 60 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 577 m; within 80 km, large variations in elevation — a maximum elevation change of 891 m.

The land around Constitución is covered by trees (35%) and water (34%) within 3 km, water (42%), trees (33%) and grassland (21%) within 16 km, and water (34%), trees (30%) and grassland (27%) within 80 km.

3 km
265 m
16 km
577 m
80 km
891 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: San Javier 68 km · Talca 70 km · Cauquenes 71 km · San Clemente 87 km · Linares 93 km · Longaví 96 km · Colbún 100 km · Sagrada Familia 101 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 Constitución (-35.3332°, -72.4116°, elevation 19 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).