San Isidro Temperature by Month

San Isidro in San José Province, Costa Rica enjoys a stable climate, with daytime temperatures staying close to 24°C (75°F) throughout the year. Explore the full monthly breakdown below.

With minimal seasonal shifts, San Isidro experiences a constant climate year-round. Maximum daytime temperatures range from a comfortable 25°C (77°F) in April to a comfortable 23°C (73°F) in November. At night, temperatures range from 17°C (63°F) in April to 16°C (61°F) in November.

The chart below illustrates the average maximum day and minimum night temperatures in San Isidro by month:

Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. April, the city's warmest month, sees 240 hours of sunshine.

The chart below shows the average temperature throughout the year:

San Isidro's average annual maximum temperature is 24°C (75°F). To put that in context, here's how it compares to a few well-known destinations:

Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.

Melbourne, Australia averages 20°C (68°F) annually, known for unpredictable weather, with four seasons sometimes happening in one day.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In San Isidro, November is the coolest month, with average highs of 23°C (73°F) and humidity around 81%, considered very high. In April, the warmest month, temperatures average 25°C (77°F) with 79% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on San Isidro's weather, including monthly rainfall, sunshine hours, and humidity, visit our San Isidro climate page.