Chillán Viejo weather in September

In September, Chillán Viejo sees average daytime highs of 16°C and overnight lows near 6°C, with 72 mm of rain across 6.9 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 15°C in the first days to 17°C by the end. The sky is clear or mostly clear about 36% 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 Chillán Viejo's 8th-clearest and 7th-windiest month. For the whole year in context, see Chillán Viejo's year-round climate.

Daytime high: 16°; 8th warmest
Overnight low: 6°; 4th coldest
Rainfall: 72 mm; 6.9 wet days
Daylight: 11 h 48 min; 7:50 AM – 7:36 PM
Cloud cover: 54%; 8th clearest
Wind: 11 km/h; 7th windiest
Solar energy: 4.58 kWh/m²
Travel score: 5.6; out of 10

Chillán Viejo is city in Chile.

Density: 3,158/km²; people per km²
Founded: 1895

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← August Chillán Viejo year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 15°C in the first days to 17°C by the end.

A typical September day in Chillán Viejo reaches about 16°C in the afternoon and slips back to 6°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 20°C. Set against its neighbours, September runs about 2°C warmer than August and about 3°C cooler than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	15	15	15	15	15	16	16	16	16	16	16	16	16	16	16	16	17	17	17	17	17	17	17	17	17	17	17	17	18	18
Avg low (°C)	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	7	7	7	7	7	7	7	7

	Avg high (°C)	Avg low (°C)
1	15	6
2	15	6
3	15	6
4	15	6
5	15	6
6	16	6
7	16	6
8	16	6
9	16	6
10	16	6
11	16	6
12	16	6
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	6
20	17	6
21	17	6
22	17	6
23	17	7
24	17	7
25	17	7
26	17	7
27	17	7
28	17	7
29	18	7
30	18	7

Chillán Viejo 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.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	27° / 13°	8	1.1	14.2	8.6
Feb	27° / 12°	18	1.6	13.4	8.6
Mar	24° / 11°	21	2.7	12.3	8.7
Apr	20° / 8°	60	5.2	11.1	7.1
May	15° / 7°	157	9.6	10.1	4.8
Jun	13° / 6°	214	13.3	9.5	3.2
Jul	13° / 4°	159	11.7	9.8	3.3
Aug	14° / 5°	132	11.3	10.6	4.1
Sep	16° / 6°	72	6.9	11.8	5.6
Oct	19° / 8°	49	6.5	12.9	6.8
Nov	22° / 9°	25	3.1	14	8.2
Dec	25° / 11°	16	2.4	14.5	8.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 49%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	44	46	46	47	49	49	50	51	51	51	51	52	52	52	53	53	52	53	53	53	52	51	51	51	51	51	51	51	52	53
Cloudier (%)	56	54	54	53	51	51	50	49	49	49	49	48	48	48	47	47	48	47	47	47	48	49	49	49	49	49	49	49	48	47

	Clearer (%)	Cloudier (%)
1	44	56
2	46	54
3	46	54
4	47	53
5	49	51
6	49	51
7	50	50
8	51	49
9	51	49
10	51	49
11	51	49
12	52	48
13	52	48
14	52	48
15	53	47
16	53	47
17	52	48
18	53	47
19	53	47
20	53	47
21	52	48
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	51	49
29	52	48
30	53	47

Chance of precipitation in September

Any precipitation

Chillán Viejo gets around 72 mm of rain over 6.9 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 24% and peaks near 33% on the wettest days. The odds ease toward the end of the month.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	33	32	31	30	29	28	27	27	26	26	25	25	24	24	23	22	22	21	21	21	20	20	21	21	21	21	21	21	21	22

	Rain chance (%)
1	33
2	32
3	31
4	30
5	29
6	28
7	27
8	27
9	26
10	26
11	25
12	25
13	24
14	24
15	23
16	22
17	22
18	21
19	21
20	21
21	20
22	20
23	21
24	21
25	21
26	21
27	21
28	21
29	21
30	22

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.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	11	calm
2	11	calm
3	11	calm
4	11	calm
5	11	calm
6	11	calm
7	11	calm
8	11	calm
9	11	calm
10	11	calm
11	11	calm
12	11	calm
13	11	calm
14	11	calm
15	11	calm
16	11	calm
17	11	calm
18	11	calm
19	11	calm
20	11	calm
21	11	calm
22	11	calm
23	11	calm
24	11	calm
25	11	calm
26	11	calm
27	11	calm
28	11	calm
29	11	calm
30	11	calm

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 7:28 AM, and sunset from 7:24 PM to 7:48 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	11.2	11.2	11.3	11.3	11.3	11.4	11.4	11.5	11.5	11.5	11.6	11.6	11.7	11.7	11.7	11.8	11.8	11.9	11.9	11.9	12.0	12.0	12.0	12.1	12.1	12.2	12.2	12.2	12.3	12.3
Sunrise (AM)	8:13	8:11	8:10	8:08	8:07	8:05	8:04	8:02	8:01	7:59	7:58	7:56	7:54	7:53	7:51	7:50	7:48	7:47	7:45	7:43	7:42	7:40	7:39	7:37	7:36	7:34	7:33	7:31	7:29	7:28
Sunset (PM)	7:24	7:24	7:25	7:26	7:27	7:28	7:29	7:29	7:30	7:31	7:32	7:33	7:33	7:34	7:35	7:36	7:37	7:38	7:38	7:39	7:40	7:41	7:42	7:43	7:43	7:44	7:45	7:46	7:47	7:48

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.2	8:13	7:24
2	11.2	8:11	7:24
3	11.3	8:10	7:25
4	11.3	8:08	7:26
5	11.3	8:07	7:27
6	11.4	8:05	7:28
7	11.4	8:04	7:29
8	11.5	8:02	7:29
9	11.5	8:01	7:30
10	11.5	7:59	7:31
11	11.6	7:58	7:32
12	11.6	7:56	7:33
13	11.7	7:54	7:33
14	11.7	7:53	7:34
15	11.7	7:51	7:35
16	11.8	7:50	7:36
17	11.8	7:48	7:37
18	11.9	7:47	7:38
19	11.9	7:45	7:38
20	11.9	7:43	7:39
21	12.0	7:42	7:40
22	12.0	7:40	7:41
23	12.0	7:39	7:42
24	12.1	7:37	7:43
25	12.1	7:36	7:43
26	12.2	7:34	7:44
27	12.2	7:33	7:45
28	12.2	7:31	7:46
29	12.3	7:29	7:47
30	12.3	7:28	7:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.58 kWh/m².

For context, solar energy here swings from a low near 1.85 kWh/m² to a high of 8.63 kWh/m² in January across the year — September's 4.58 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	3.7	3.7	3.8	3.9	3.9	4.0	4.0	4.1	4.2	4.2	4.3	4.4	4.4	4.5	4.5	4.6	4.7	4.7	4.8	4.8	4.9	4.9	5.0	5.0	5.1	5.1	5.2	5.2	5.3	5.3
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	3.7	Moderate
2	3.7	Moderate
3	3.8	Moderate
4	3.9	Moderate
5	3.9	Moderate
6	4.0	Moderate
7	4.0	Bright
8	4.1	Bright
9	4.2	Bright
10	4.2	Bright
11	4.3	Bright
12	4.4	Bright
13	4.4	Bright
14	4.5	Bright
15	4.5	Bright
16	4.6	Bright
17	4.7	Bright
18	4.7	Bright
19	4.8	Bright
20	4.8	Bright
21	4.9	Bright
22	4.9	Bright
23	5.0	Bright
24	5.0	Bright
25	5.1	Bright
26	5.1	Bright
27	5.2	Bright
28	5.2	Bright
29	5.3	Bright
30	5.3	Bright

Planning a trip in September

Hazard calendar for Chillán Viejo

In seasonPeak

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

Chillán Viejo'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 Chillán Viejo?

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

5.6

Sightseeing

8th-best month of the year

1.0

Beach & pool

8th-best month of the year

September is a reasonable time to visit Chillán Viejo for sightseeing.

What to pack for Chillán Viejo in September

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

In September, Chillán Viejo sees daytime highs around 16°C and nights near 6°C. Worth packing: a warm layer and sun protection. About 7 days see rain.

a warm layersun protection

UV index in Chillán Viejo in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Chillán Viejo peaks around January 14 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 16 at about 2 (moderate).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	13	11	9	5	3	2	3	3	5	8	10	12
Level	Extreme	Extreme	Very high	Moderate	Moderate	Moderate	Moderate	Moderate	High	Very high	Extreme	Extreme

	UV index (midday)	Level
Jan	13	Extreme
Feb	11	Extreme
Mar	9	Very high
Apr	5	Moderate
May	3	Moderate
Jun	2	Moderate
Jul	3	Moderate
Aug	3	Moderate
Sep	5	High
Oct	8	Very high
Nov	10	Extreme
Dec	12	Extreme

Air quality in Chillán Viejo 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 Chillán Viejo is worst in April — around 40 µg/m³ PM2.5 (poor), about 4.6× the cleanest month (December, 9 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	14	25	30	40	27	15	15	14	13	12	10	9
Level	Moderate	Moderate	Moderate	Poor	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good	Good

	PM2.5 (µg/m³)	Level
Jan	14	Moderate
Feb	25	Moderate
Mar	30	Moderate
Apr	40	Poor
May	27	Moderate
Jun	15	Moderate
Jul	15	Moderate
Aug	14	Moderate
Sep	13	Moderate
Oct	12	Moderate
Nov	10	Good
Dec	9	Good

Location & terrain

Where is Chillán Viejo?

Chillán Viejo sits at 36.6°S, 72.1°W, 117 m above sea level, in Chile. The nearest listed city is Chillán, 3.0 km away.

Topography around Chillán Viejo

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

Within 3 km, the terrain around Chillán Viejo has only modest variations in elevation — a maximum elevation change of 50 m around an average of 105 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 189 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,164 m.

The land around Chillán Viejo is covered by artificial surfaces (39%), grassland (25%) and cropland (20%) within 3 km, trees (33%), grassland (33%) and cropland (26%) within 16 km, and trees (50%) and grassland (26%) within 80 km.

3 km

50 m

artificial surfaces 39%

16 km

189 m

trees 33%

80 km

3,164 m

trees 50%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwater

← August Chillán Viejo year-round climate October →Best places to visit in September

September weather nearby: Chillán 3.0 km · Coihueco 27 km · San Carlos 27 km · Quillón 33 km · Cabrero 52 km · Coelemu 53 km · Parral 60 km · Tomé 74 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

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 Chillán Viejo (-36.623°, -72.1319°, elevation 117 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).

	Avg high (°C)	Avg low (°C)
1	15	6
2	15	6
3	15	6
4	15	6
5	15	6
6	16	6
7	16	6
8	16	6
9	16	6
10	16	6
11	16	6
12	16	6
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	6
20	17	6
21	17	6
22	17	6
23	17	7
24	17	7
25	17	7
26	17	7
27	17	7
28	17	7
29	18	7
30	18	7

	Clearer (%)	Cloudier (%)
1	44	56
2	46	54
3	46	54
4	47	53
5	49	51
6	49	51
7	50	50
8	51	49
9	51	49
10	51	49
11	51	49
12	52	48
13	52	48
14	52	48
15	53	47
16	53	47
17	52	48
18	53	47
19	53	47
20	53	47
21	52	48
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	51	49
29	52	48
30	53	47

	Rain chance (%)
1	33
2	32
3	31
4	30
5	29
6	28
7	27
8	27
9	26
10	26
11	25
12	25
13	24
14	24
15	23
16	22
17	22
18	21
19	21
20	21
21	20
22	20
23	21
24	21
25	21
26	21
27	21
28	21
29	21
30	22

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°C)	Avg low (°C)
1	15	6
2	15	6
3	15	6
4	15	6
5	15	6
6	16	6
7	16	6
8	16	6
9	16	6
10	16	6
11	16	6
12	16	6
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	6
20	17	6
21	17	6
22	17	6
23	17	7
24	17	7
25	17	7
26	17	7
27	17	7
28	17	7
29	18	7
30	18	7

	Clearer (%)	Cloudier (%)
1	44	56
2	46	54
3	46	54
4	47	53
5	49	51
6	49	51
7	50	50
8	51	49
9	51	49
10	51	49
11	51	49
12	52	48
13	52	48
14	52	48
15	53	47
16	53	47
17	52	48
18	53	47
19	53	47
20	53	47
21	52	48
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	51	49
29	52	48
30	53	47

	Rain chance (%)
1	33
2	32
3	31
4	30
5	29
6	28
7	27
8	27
9	26
10	26
11	25
12	25
13	24
14	24
15	23
16	22
17	22
18	21
19	21
20	21
21	20
22	20
23	21
24	21
25	21
26	21
27	21
28	21
29	21
30	22

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°C)	Avg low (°C)
1	15	6
2	15	6
3	15	6
4	15	6
5	15	6
6	16	6
7	16	6
8	16	6
9	16	6
10	16	6
11	16	6
12	16	6
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	6
20	17	6
21	17	6
22	17	6
23	17	7
24	17	7
25	17	7
26	17	7
27	17	7
28	17	7
29	18	7
30	18	7

	Clearer (%)	Cloudier (%)
1	44	56
2	46	54
3	46	54
4	47	53
5	49	51
6	49	51
7	50	50
8	51	49
9	51	49
10	51	49
11	51	49
12	52	48
13	52	48
14	52	48
15	53	47
16	53	47
17	52	48
18	53	47
19	53	47
20	53	47
21	52	48
22	51	49
23	51	49
24	51	49
25	51	49
26	51	49
27	51	49
28	51	49
29	52	48
30	53	47

	Rain chance (%)
1	33
2	32
3	31
4	30
5	29
6	28
7	27
8	27
9	26
10	26
11	25
12	25
13	24
14	24
15	23
16	22
17	22
18	21
19	21
20	21
21	20
22	20
23	21
24	21
25	21
26	21
27	21
28	21
29	21
30	22

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100