Climate averages 1991–2020
Trelew weather
in September.
A mild, fairly dry month: the 8th warmest and the joint 5th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Trelew: daytime highs average 17.3°C and nights cool to about 6.1°C. By daytime temperature it is the 8th warmest of the 12 months.
Expect about 18 mm of rain on roughly 4 days, which makes September a fairly dry month (the joint 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 46 min on an average September day.
The nearest other city in this atlas is Comodoro Rivadavia (338 km away). In September its highs average 13.3°C, 4.0°C cooler than Trelew, with 21 mm of rain.
Among the 67 cities listed in Argentina, Trelew ranks joint 55th of 67 for the warmest September highs and 5th of 67 for the driest September (rainfall, lowest first). The mean September high of those 67 cities is 19.4°C; Trelew is 2.1°C cooler than that mean.
From September to October, average highs rise by 3.9°C to 21.3°C, and monthly rainfall stays at 18 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
Trelew climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.1°C16.2°C | 16.2°C | 15 | 3.0 | 15.015 h |
| February | 27.5°C15.2°C | 15.2°C | 22 | 3.7 | 13.814 h |
| March | 25.1°C13.5°C | 13.5°C | 21 | 3.5 | 12.412 h |
| April | 20.4°C9.8°C | 9.8°C | 19 | 2.9 | 10.911 h |
| May | 15.8°C6.5°C | 6.5°C | 23 | 4.0 | 9.710 h |
| June | 12.1°C3.4°C | 3.4°C | 23 | 4.1 | 9.09 h |
| July | 11.8°C2.5°C | 2.5°C | 14 | 3.5 | 9.39 h |
| August | 14.5°C4.3°C | 4.3°C | 14 | 3.4 | 10.410 h |
| September, selected | 17.3°C6.1°C | 6.1°C | 18 | 4.0 | 11.812 h |
| October | 21.3°C9.2°C | 9.2°C | 18 | 4.1 | 13.213 h |
| November | 24.7°C12.2°C | 12.2°C | 16 | 3.2 | 14.615 h |
| December | 27.3°C14.5°C | 14.5°C | 18 | 3.0 | 15.315 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
- Comodoro Rivadavia in SeptemberArgentina · 338 kmHigh 13.3°C · Low 6.5°C · 21 mm rain
- General Roca in SeptemberArgentina · 506 kmHigh 18.7°C · Low 7.0°C · 21 mm rain
- Cipolletti in SeptemberArgentina · 530 kmHigh 18.5°C · Low 6.7°C · 19 mm rain
- Neuquén in SeptemberArgentina · 531 kmHigh 18.3°C · Low 6.5°C · 19 mm rain
- San Carlos de Bariloche in SeptemberArgentina · 547 kmHigh 7.2°C · Low 0.8°C · 68 mm rain
- Bahía Blanca in SeptemberArgentina · 565 kmHigh 17.6°C · Low 8.0°C · 45 mm rain
- Puerto Montt in SeptemberChile · 658 kmHigh 12.0°C · Low 5.5°C · 185 mm rain
- Osorno in SeptemberChile · 712 kmHigh 12.9°C · Low 4.5°C · 129 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 Trelew) is explained once on the Trelew year overview and on the Sources, method and limits page.