Ostional Temperature by Month

The average annual maximum temperature in Ostional, Guanacaste, Costa Rica is 30°C (86°F), with little variation between seasons. This page covers monthly averages, day-night differences, and how Ostional compares to cities worldwide.

The temperature in Ostional changes very little across the seasons, maintaining a similar climate throughout the year. Maximum daytime temperatures range from a comfortable 29°C (84°F) in October to a very warm 32°C (90°F) in March. Nighttime lows range from 25°C (77°F) in March to 24°C (75°F) in October.

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

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak.

The chart below shows the average temperature throughout the year:

Ostional's average annual maximum temperature is 30°C (86°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.

Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters, and seasons reversed compared to Europe.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

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 Ostional's weather, including monthly rainfall, sunshine hours, and humidity, visit our Ostional climate page.