About San Juan, Alajuela Province's Climate & Weather History

With a population of around 7,700, San Juan sits in Alajuela Province, Costa Rica. The city operates in the America/Costa Rica time zone.

In 2025, San Juan recorded an average annual temperature of 69°F. The hottest temperatures reached 87°F in March; the coolest were 53°F in March. Total precipitation for the year was 152 inches, with the wettest month being May.