Climate averages 1991–2020
Santiago weather
in September.
A mild, moderately wet month: the 9th warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Santiago: daytime highs average 17.6°C and nights cool to about 5.0°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 55 mm of rain on roughly 8 days, which makes September a moderately wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 51 min on an average September day.
The nearest other city in this atlas is Peñalolén (11 km away). In September its highs average 16.3°C, 1.3°C cooler than Santiago, with 72 mm of rain.
Among the 40 cities listed in Chile, Santiago ranks 18th of 40 for the warmest September highs and joint 17th of 40 for the driest September (rainfall, lowest first). The mean September high of those 40 cities is 17.2°C; Santiago is 0.4°C warmer than that mean.
From September to October, average highs rise by 2.5°C to 20.1°C, and monthly rainfall falls from 55 mm to 39 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Santiago climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 28.0°C16.6°C | 16.6°C | 2.7 | 0.7 | 14.114 h |
| February | 27.5°C16.2°C | 16.2°C | 4.5 | 0.9 | 13.313 h |
| March | 26.1°C14.7°C | 14.7°C | 8.6 | 1.2 | 12.312 h |
| April | 22.2°C10.1°C | 10.1°C | 28 | 3.3 | 11.311 h |
| May | 18.4°C6.1°C | 6.1°C | 62 | 6.0 | 10.410 h |
| June | 14.7°C2.8°C | 2.8°C | 109 | 7.3 | 10.010 h |
| July | 13.8°C1.9°C | 1.9°C | 86 | 7.1 | 10.210 h |
| August | 15.4°C3.0°C | 3.0°C | 81 | 7.7 | 10.911 h |
| September, selected | 17.6°C5.0°C | 5.0°C | 55 | 7.8 | 11.912 h |
| October | 20.1°C7.5°C | 7.5°C | 39 | 6.1 | 12.913 h |
| November | 23.4°C10.6°C | 10.6°C | 16 | 2.6 | 13.814 h |
| December | 26.2°C14.1°C | 14.1°C | 6.3 | 1.0 | 14.314 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Peñalolén in SeptemberChile · 11 kmHigh 16.3°C · Low 4.9°C · 72 mm rain
- Quilicura in SeptemberChile · 12 kmHigh 18.0°C · Low 6.4°C · 77 mm rain
- Maipú in SeptemberChile · 13 kmHigh 18.4°C · Low 5.9°C · 55 mm rain
- San Bernardo in SeptemberChile · 16 kmHigh 18.4°C · Low 4.8°C · 55 mm rain
- Puente Alto in SeptemberChile · 18 kmHigh 17.2°C · Low 3.8°C · 72 mm rain
- Peñaflor in SeptemberChile · 27 kmHigh 19.0°C · Low 6.2°C · 41 mm rain
- Colina in SeptemberChile · 28 kmHigh 18.8°C · Low 7.8°C · 77 mm rain
- Lampa in SeptemberChile · 28 kmHigh 19.5°C · Low 8.1°C · 39 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Santiago) is explained once on the Santiago year overview and on the Sources, method and limits page.
Maipú and San Bernardo lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.