Air Quality Index (AQI) in Costa Rica 🇨🇷

Live Air Quality Index (AQI) and PM2.5 Levels in Costa Rica

Currently, the Air Quality Index (AQI) in San Jose, the capital of Costa Rica, is measured at a score of 26. According to the US EPA health standard, this air quality rating is categorized as Good. The current atmosphere in San Jose is influenced by a PM2.5 (fine particulate matter) concentration of 4.6 µg/m³ and PM10 levels recorded at 5.3 µg/m³. Monitoring of gaseous pollutants shows Nitrogen Dioxide (NO2) at 8.9 µg/m³.

Beyond the primary urban hubs, atmospheric conditions and smog levels fluctuate across Costa Rica based on industrial output, traffic density, and local weather patterns. Real-time pollution data and respiratory health alerts are also being actively monitored in cities like Limón, Alajuela and Liberia. Tracking these air quality metrics is essential for residents nationwide to manage outdoor exposure and maintain respiratory safety during periods of increased particulate concentration.

Air Quality Snapshot: Costa Rica Right Now

Across 4 monitored cities in Costa Rica, live air quality currently ranges from a low of 9 AQI in Liberia (the cleanest air right now) to a high of 32 AQI in Alajuela (the most polluted). By US EPA health band, the nationwide distribution stands at 4 Good. The average fine-particulate (PM2.5) concentration across these cities is 3.6 µg/m³ — approximately 0.7 times the World Health Organization (WHO) annual air quality guideline of 5 µg/m³.

Costa Rica Air Quality: Major Cities Index

San Jose
1
Limón
1

Alajuela
1
Liberia
1

* Air Quality Index (AQI) data for Costa Rica is calculated using the US EPA standard. Information is processed from multiple monitoring stations detecting PM2.5, PM10, and gaseous pollutants to ensure accuracy for respiratory health planning.

What Today's Readings Mean in Costa Rica

The median reading across 4 monitored cities is 20.0 AQI. The national spread is 23 points, from 9 in Liberia to 32 in Alajuela. Average PM2.5 is 3.6 µg/m³ (0.7× the WHO annual guideline).

All monitored locations are currently in the Good range. Normal outdoor activity is appropriate for most people.

See the complete AQI and pollutant reference scales

Health & Scientific Resources

→ How to read US EPA Air Quality Index before going outside → Understanding Air Quality Index levels and what they mean → When haze forms and what it does to air quality

Air Quality in Costa Rica — FAQ

Common questions about AQI levels, pollutants, and data sources for Costa Rica.

What is the current air quality in Costa Rica?

Live AQI readings for 4 city(ies) across Costa Rica are listed above on the US EPA 0-500 scale.

Where does Costa Rica's AQI data come from?

Real-time readings come from ground-based monitoring stations operated by national environmental agencies in Costa Rica, delivered via WeatherAPI.com and aggregated using the EPA AQI formula.

What is a healthy AQI value in Costa Rica?

On the EPA scale used worldwide, 0-50 is Good, 51-100 is Moderate, 101-150 is Unhealthy for sensitive groups, 151-200 is Unhealthy, 201-300 is Very Unhealthy, and 301-500 is Hazardous. The WHO 24-hour PM2.5 guideline is 15 μg/m³.

Why do AQI readings vary between cities in Costa Rica?

Air quality is highly local — major pollution sources (traffic, industry, dust, wildfires) cluster around cities, while wind direction and topography move them around. Comparing nearby readings on this page is the best way to see how conditions change across Costa Rica.