Santiago Weather in September
In September, Santiago averages a high of 21°C (69°F) and a low of 6°C (42°F), from 17 years of daily records (1976–2025).
21°C
Average high
69°F
6°C
Average low
42°F
32°C
Record high
89°F · September 17, 2017
-5°C
Record low
23°F · September 1, 1974
What September Is Like in Santiago
- 9 of the 10 warmest Septembers on record in Santiago have come since 2010.
- The coldest September reading, -5°C (23°F) on September 1, 1974, has not been matched in 51 years.
- September is the least predictable month in Santiago: daytime highs vary more from day to day and year to year than in any other month.
- On average, 0.7 nights in September drop below freezing.
At least 1 mm of rain falls on 10% of September days, and the month averages 12 mm in total.
Warmest: 2011 (24.3°C)Latest: 2020 (23.9°C)10-year averageLong-run average (21.0°C)
Look Up a Day in September
See the weather in Santiago on any September date, year by year.
Source: NOAA GHCN-Daily, Arturo Merino Benitez Intl (1973–2025); Quinta Normal (2005–2025). Averages cover 1976–2025. How we compute this