Chile Santiago Weather in September — Climate Guide
September in Santiago is very-high
Santiago Weather in September — Quick Answer
As of 2026- Avg temp
- 19° / 7°
- Rainfall
- 30mm · 4 days
- Crowds
- Busy
As of 2026, Santiago in September averages a high of 19°C and low of 7°C with 30mm of rain over about 4 days. Spring begins — milder, brighter, drier, with smog clearing. Highs near 19°C/66°F, nights around 7°C/45°F. Layers and a light jacket, plus a rain layer for the odd shower. SPF 30+ as sun strengthens.
September is very-high for Santiago.
September is spring's arrival and one of Santiago's most exciting months — milder, brighter days (highs near 19°C/66°F), the smog clearing, blossom appearing, and the city building toward its biggest party.
That party is Fiestas Patrias — the 'Dieciocho' around September 18-19, celebrating independence with a week of fondas and ramadas (festival tents), cueca dancing (the national dance), asados (barbecues), empanadas, chicha, terremotos, and rodeo. Parque O'Higgins and Parque Padre Hurtado host the biggest Santiago fondas. It's joyful and intensely local — come for it deliberately, or plan around the partial shutdown.
Travel score
Santiago September Weather Stats
Avg High
19°C
Avg Low
7°C
Rainy Days
4
30mm total
Sunshine
6.5h
Daily avg
Humidity
65%
comfortable
UV Index
6
High
Wind
10 km/h
Gusts 22
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
26 μg/m³
PM10
46 μg/m³
Status
moderate
Feels-Like Temperature & Wind
Feels like
Daytime
18°C
Nighttime
6°C
Humidity and wind affect how the actual temperature feels.
Wind
10 km/h
Max gust 22 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Spring weather returns — bright and milder
- Fiestas Patrias — Chile's biggest celebration
- Smog clears; Andes views sharpen
- Late high-resort skiing early in the month
Cons
- Hotels/flights spike around Sep 18-19
- Partial city shutdown on the holidays
- Occasional spring showers
- Book the Dieciocho week well ahead
September Events & Festivals
- Fiestas Patrias (the 'Dieciocho', around Sep 18-19) — Chile's biggest national celebration
- Fondas, cueca dancing, asados, empanadas, terremotos & rodeo
- Spring blossom begins; smog clears
- Late ski season at high resorts (early Sep)
Santiago in September — Full Picture
September is spring's arrival and one of Santiago's most exciting months — milder, brighter days (highs near 19°C/66°F), the smog clearing, blossom appearing, and the city building toward its biggest party.
That party is Fiestas Patrias — the 'Dieciocho' around September 18-19, celebrating independence with a week of fondas and ramadas (festival tents), cueca dancing (the national dance), asados (barbecues), empanadas, chicha, terremotos, and rodeo. Parque O'Higgins and Parque Padre Hurtado host the biggest Santiago fondas. It's joyful and intensely local — come for it deliberately, or plan around the partial shutdown.
The weather is genuinely pleasant for sightseeing again, the Andes views sharpen as smog lifts, and the higher ski resorts can still run early in the month. It's a top time to visit, balanced against the Dieciocho crowds and price spike.
Note: book hotels and any travel well ahead for the Sep 18-19 holiday week — the city and coast fill up, flights spike, and many shops close on the 18th and 19th themselves.
What to Wear & What to Pack
Spring begins — milder, brighter, drier, with smog clearing. Highs near 19°C/66°F, nights around 7°C/45°F. Layers and a light jacket, plus a rain layer for the odd shower. SPF 30+ as sun strengthens.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
22.7°C
8°C
3.7/mo
Summer (Jun·Jul·Aug)
15.7°C
4.3°C
6/mo
Autumn (Sep·Oct·Nov)
Current22.3°C
9°C
3/mo
Winter (Dec·Jan·Feb)
29°C
11.3°C
1/mo
Santiago Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 30° | 12° | 1d·1mm | 11h | 45% | 11 | Busy | Peak | |
| 29° | 11° | 1d·2mm | 10.5h | 47% | 11 | Busy | Peak | |
| March (Best) | 27° | 10° | 2d·5mm | 9h | 52% | 8 | Moderate | Shoulder |
| 23° | 8° | 3d·15mm | 7h | 58% | 6 | Moderate | Shoulder | |
| 18° | 6° | 6d·65mm | 5h | 70% | 4 | Quiet | Low season | |
| 15° | 4° | 7d·80mm | 4h | 78% | 2 | Quiet | Shoulder | |
| 15° | 4° | 6d·75mm | 4.5h | 78% | 2 | Moderate | Shoulder | |
| 17° | 5° | 5d·55mm | 5.5h | 73% | 3 | Moderate | Shoulder | |
| September (Best) | 19° | 7° | 4d·30mm | 6.5h | 65% | 6 | Busy | Peak |
| October (Best) | 22° | 9° | 3d·15mm | 8h | 58% | 8 | Busy | Shoulder |
| November (Best) | 26° | 11° | 2d·8mm | 9.5h | 50% | 10 | Busy | Shoulder |
| 28° | 11° | 1d·3mm | 10.5h | 47% | 11 | Busy | Peak |
View Other Months
Santiago September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Santiago?
Santiago in September is very-high. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Santiago in September?
Santiago September averages a high of 19°C and a low of 7°C.
Does it rain much in Santiago in September?
Santiago September averages 30mm of rainfall over about 4 rainy days.
What should I wear in Santiago in September?
Spring begins — milder, brighter, drier, with smog clearing. Highs near 19°C/66°F, nights around 7°C/45°F. Layers and a light jacket, plus a rain layer for the odd shower. SPF 30+ as sun strengthens.
What time are sunrise and sunset in Santiago in September?
Santiago September sunrise is 07:25 and sunset is 19:15, with 11h 50min of daylight.
What's the air quality like in Santiago in September?
Santiago September air quality (AQI) averages 58, rated Moderate. PM2.5 averages 26μg/m³.
What activities are recommended in Santiago in September?
In September, Santiago is great for Fiestas Patrias fondas & cueca (Sep 18-19), Spring city sightseeing, Sharper Andes views as smog clears.
Is September peak season in Santiago?
Santiago September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Santiago
View Other Months
Planning a September trip to Santiago?
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Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.