Antofagasta weather in September

In September, Antofagasta sees average daytime highs of 15°C and overnight lows near 13°C, with 5 mm of rain across 1.8 wet days and about 11.9 hours of daylight. It is the 11th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 15°C through the month. The sky is clear or mostly clear about 59% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 30 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Antofagasta's 5th-clearest and 7th-windiest month. For the whole year in context, see Antofagasta's year-round climate.

Daytime high
15°
11th warmest
Overnight low
13°
2nd coldest
Rainfall
5 mm
1.8 wet days
Daylight
11 h 54 min
7:40 AM – 7:32 PM
Cloud cover
36%
5th clearest
Wind
12 km/h
7th windiest
Solar energy
6.34 kWh/m²
Travel score
5.8
out of 10

Antofagasta is city in Antofagasta Region, Chile.

Air quality
Moderate
PM2.5 12 µg/m³ · 2019
Density
7,147/km²
people per km²
Founded
1868

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 15°C through the month.

A typical September day in Antofagasta reaches about 15°C in the afternoon and slips back to 13°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 16°C. Set against its neighbours, September runs on par with August and on par with October.

10°13°15°18°20°151015202530
Avg high (°C)Avg low (°C)
11513
21513
31513
41513
51513
61513
71513
81513
91513
101513
111513
121513
131513
141513
151513
161513
171513
181513
191513
201513
211513
221513
231513
241513
251513
261513
271513
281513
291513
301513

Antofagasta weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan20° / 18°20.113.38.1
Feb20° / 18°20.512.88.2
Mar19° / 17°40.612.28.0
Apr18° / 16°92.811.57.1
May17° / 15°103.910.96.3
Jun16° / 14°13410.65.9
Jul15° / 13°103.810.75.6
Aug15° / 13°82.611.25.6
Sep15° / 13°51.811.95.8
Oct16° / 13°50.912.66.1
Nov17° / 15°40.713.16.8
Dec18° / 16°20.113.47.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 25% of September, with mostly cloudy or overcast conditions the remaining 16%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18416
28416
38416
48416
58416
68416
78416
88416
98416
108416
118416
128416
138416
148515
158515
168416
178416
188416
198416
208416
218515
228515
238416
248416
258515
268515
278515
288515
298614
308614

Chance of precipitation in September

Any precipitation

Antofagasta gets around 5 mm of rain over 1.8 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 6% and peaks near 6% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
16
26
36
46
56
66
76
86
96
106
116
126
136
146
156
166
176
186
196
206
216
226
236
246
255
265
275
285
295
305

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 66% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
17327
27228
37129
47129
57030
67030
77030
86931
96931
106931
116931
126931
136931
146832
156832
166832
176733
186634
196535
206535
216436
226337
236238
246139
256040
266040
275941
285842
295743
305644

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812light breeze
2912light breeze
3012light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 30 min at the start of September to 12 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over September. Sunrise moves from 7:56 AM to 7:25 AM, and sunset from 7:27 PM to 7:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:567:27
211.57:557:27
311.67:547:28
411.67:537:28
511.67:527:28
611.67:517:29
711.77:507:29
811.77:497:29
911.77:477:30
1011.77:467:30
1111.77:457:30
1211.87:447:31
1311.87:437:31
1411.87:427:31
1511.87:417:32
1611.97:407:32
1711.97:397:32
1811.97:387:33
1911.97:377:33
2012.07:367:33
2112.07:357:34
2212.07:347:34
2312.07:327:34
2412.17:317:35
2512.17:307:35
2612.17:297:35
2712.17:287:36
2812.17:277:36
2912.27:267:36
3012.27:257:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.34 kWh/m².

For context, solar energy here swings from a low near 3.95 kWh/m² to a high of 8.34 kWh/m² in December across the year — September's 6.34 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.8Bright
25.8Bright
35.8Bright
45.9Bright
55.9Bright
66.0Bright
76.0Intense
86.0Intense
96.1Intense
106.1Intense
116.2Intense
126.2Intense
136.2Intense
146.3Intense
156.3Intense
166.3Intense
176.4Intense
186.4Intense
196.5Intense
206.5Intense
216.6Intense
226.6Intense
236.6Intense
246.7Intense
256.7Intense
266.8Intense
276.8Intense
286.8Intense
296.9Intense
306.9Intense
Planning a trip in September

Is September a good time to visit Antofagasta?

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

5.8
Sightseeing
10th-best month of the year
0.0
Beach & pool
11th-best month of the year

September is a reasonable time to visit Antofagasta for sightseeing.

What to pack for Antofagasta in September

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

In September, Antofagasta sees daytime highs around 15°C and nights near 13°C. Pack sun protection. Worth having: a warm layer.

sun protectiona warm layer

Sea temperature near Antofagasta in September

The nearest coast averages about 15°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in January at about 20°C and coldest in August near 15°C.

It's comfortable for a long swim from Jan 16 to Feb 17 — about 1.1 months when the water holds above 20°C.

14°16°18°20°22°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan20Refreshing
Feb20Refreshing
Mar19Cool
Apr18Cool
May17Cool
Jun16Cool
Jul15Cool
Aug15Cool
Sep15Cool
Oct16Cool
Nov18Cool
Dec19Cool

UV index in Antofagasta in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Antofagasta peaks around February 10 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 10 at about 5 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeFeb 10UV 15Jul 10UV 5
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep10Very high
Oct12Extreme
Nov13Extreme
Dec14Extreme

Air quality in Antofagasta 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 Antofagasta is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (March, 7 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Antofagasta's WHO annual average of 12 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1719 µg/m³Mar 127 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb8Good
Mar7Good
Apr10Good
May16Moderate
Jun17Moderate
Jul19Moderate
Aug17Moderate
Sep14Moderate
Oct11Good
Nov10Good
Dec8Good
Location & terrain

Where is Antofagasta?

Antofagasta sits at 23.7°S, 70.4°W, 276 m above sea level, in Chile. The nearest listed city is Tocopilla, 175 km away.

Alto HospicioCalderaPozo AlmonteIquiqueCopiapó

Topography around Antofagasta

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

Within 3 km, the terrain around Antofagasta has significant variations in elevation — a maximum elevation change of 487 m around an average of 103 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,138 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,608 m.

The land around Antofagasta is covered by water (40%), artificial surfaces (30%) and bare terrain (30%) within 3 km, bare terrain (54%) and water (42%) within 16 km, and bare terrain (68%) and water (32%) within 80 km.

3 km
487 m
16 km
1,138 m
80 km
2,608 m
artificial surfacesbare terrainwater
September weather nearby: Tocopilla 175 km · Calama 201 km · San Pedro de Atacama 239 km · Alto Hospicio 377 km · Caldera 382 km · Pozo Almonte 383 km · Iquique 383 km · Copiapó 413 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 Antofagasta (-23.6509°, -70.3975°, elevation 276 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. 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).