Climate Overview
The climate in San Isidro is temperate. The average annual temperature is 17°C and approximately 3435mm 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 9°C range. May is the warmest month, though highs remain moderate at 22°C with a mean of 18°C. January is the coolest month, with minimum temperatures around 13°C and an average of 17°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
San Isidro is a very wet location, receiving approximately 3435mm of precipitation annually, which averages out to around 286mm per month. The wettest month is October, averaging 614mm of rainfall. May and September also tend to see above-average precipitation. The driest month is February, with just 46mm. That's 568mm 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 1km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 2km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 1km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 1km/h gap between the calmest and windiest months.
Seasons
93 days until Autumn
It is currently summer in San Isidro, which began on June 21, 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 22°C, while the coldest stretch bottoms out in January near 13°C. Autumn is next, beginning on September 23, 2026 — 93 days from now.
Spring
Temperatures range from 13 to 22°C. Rainfall is heavy, totalling around 760mm across the season with a monthly average of 253mm. Winds are generally light, averaging 1km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 15 to 22°C. Rainfall is heavy, totalling around 1036mm across the season with a monthly average of 345mm. Winds are generally light, averaging 1km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from 14 to 22°C. Rainfall is heavy, totalling around 1386mm across the season with a monthly average of 462mm. Winds are generally light, averaging 1km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 13 to 21°C. Precipitation is moderate at around 254mm for the season, averaging 85mm per month. Winds are generally light, averaging 1km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Best Time to Visit
The best time to visit San Isidro is during January, February and March, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 63mm per month. By contrast, May can be uncomfortably hot with temperatures reaching 22°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.
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.
