Climate Overview
The climate in San Isidro is warm and mild. The average annual temperature is 23°C and approximately 6869mm of precipitation falls per year. San Isidro receives a notable amount of rainfall throughout the year, including during its driest month. San Isidro sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
San Isidro has relatively stable temperatures year-round, staying within a 5°C range. May is the warmest month, though highs remain moderate at 25°C with a mean of 23°C. January is the coolest month, with minimum temperatures around 20°C and an average of 22°C. Daily temperature variation is modest, with an average difference of 3°C between highs and lows.
Precipitation
San Isidro is a very wet location, receiving approximately 6869mm of precipitation annually, which averages out to around 572mm per month. The wettest month is October, averaging 1044mm of rainfall. November and August also tend to see above-average precipitation. The driest month is February, with just 120mm. That's 924mm less than October, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
San Isidro is relatively calm, with an average annual wind speed of 5km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 6km/h, though still comfortable for most outdoor activities. The calmest conditions occur in April, with average winds dropping to 4km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.
Seasons
87 days until Winter
It is currently autumn in San Isidro, which began on September 23, 2026. San Isidro sits near the equator, so the traditional four-season cycle is less pronounced. Temperatures remain relatively stable year-round. The warmest period peaks in May at around 25°C, while the coldest stretch bottoms out in January near 20°C. Winter is next, beginning on December 21, 2026 (87 days from now).
Spring
Temperatures range from 21 to 25°C. Rainfall is heavy, totalling around 1171mm across the season with a monthly average of 390mm. Winds are generally light, averaging 5km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 21 to 24°C. Rainfall is heavy, totalling around 2313mm across the season with a monthly average of 771mm. Winds are generally light, averaging 5km/h. Light, breathable clothing is ideal. Perfect conditions for outdoor activities.
Autumn
Temperatures range from 21 to 24°C. Rainfall is heavy, totalling around 2730mm across the season with a monthly average of 910mm. Winds are generally light, averaging 5km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 20 to 24°C. Rainfall is heavy, totalling around 655mm across the season with a monthly average of 218mm. Winds are generally light, averaging 5km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for San Isidro based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
