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San Isidro weather by month
Historical averages 2016–2025 · not a forecast
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When is the best time to visit San Isidro?
For a warm holiday, the best week has been 3–9 February (Weather Index 96). Favourable start dates for a 7-day trip run from 26 January to 10 February. March, April and May are warmest (25°C), February is driest and January, February and March have the most sun.
- Warmest
- March, April and May 25°C
- Coolest
- November 23°C
- Driest
- February 74% rain-day chance
- Wettest
- June to September 100% rain-day chance
- Sunniest
- January, February and March 11 hours a day
A rain day has 1 mm or more, snow included, so a short shower counts. Monthly averages below give the amounts.
Monthly averages in San Isidro
San Isidro historical monthly estimates, 2016–2025. Temperatures and sunshine are daily averages.
| Month | High (°C) | Low (°C) | Rain-day chance (%) | Expected rain days | Precipitation (mm/month) | Sunshine (hours/day) |
|---|---|---|---|---|---|---|
| January | 23.9 | 20.0 | 81.3 | 25.2 | 167.1 | 10.9 |
| February | 24.4 | 20.4 | 74.3 | 20.8 | 112.8 | 11.3 |
| March | 24.5 | 20.7 | 77.7 | 24.1 | 131.2 | 11.2 |
| April | 24.5 | 21.2 | 96.7 | 29.0 | 368.4 | 10.1 |
| May | 24.6 | 21.5 | 98.7 | 30.6 | 662.4 | 8.0 |
| June | 24.3 | 21.1 | 100.0 | 30.0 | 666.1 | 7.2 |
| July | 24.1 | 21.0 | 100.0 | 31.0 | 777.6 | 7.6 |
| August | 24.1 | 20.9 | 100.0 | 31.0 | 857.0 | 7.5 |
| September | 24.1 | 20.8 | 100.0 | 30.0 | 765.6 | 7.1 |
| October | 23.8 | 20.6 | 98.7 | 30.6 | 1038.5 | 6.5 |
| November | 23.5 | 20.4 | 99.7 | 29.9 | 918.2 | 7.6 |
| December | 23.6 | 20.0 | 92.3 | 28.6 | 353.7 | 10.1 |
Each month averages its own days. Precipitation includes snow. About the data
Sources
Open-Meteo · 1 Jan 2016 – 31 Dec 2025
- Open-Meteo Historical Weather API
- Local days, 2016–2025, every year weighted equally. Each weekly chart averages its own seven days, without smoothing.
- Shading shows the 10th–90th percentile of past days, not forecast confidence.
- A rain day has at least 1 mm, snow included. The last weekly period has eight days.
- Wind is the average daytime (10:00–18:00) maximum, not gusts. Daylight is calculated from latitude. Missing readings stay blank.
- Mugginess (dew point) comes from the original daily summaries, on UTC days.
- The live two-week forecast comes from the Open-Meteo Weather Forecast API. The Weather Index does not use it.