SmogRank / Countries / Costa Rica
Most polluted cities in Costa Rica
0 measured cities, last 24 hours.
No city has enough measurements for this window yet.
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+
Estimated: cities without a monitor
Costa Rica cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| San José | ≈ 8 µg/m³ |
| Limón | ≈ 5 µg/m³ |
| Alajuela | ≈ 8 µg/m³ |
| Liberia | ≈ 4 µg/m³ |
| Paraíso | ≈ 8 µg/m³ |
| Puntarenas | ≈ 6 µg/m³ |
| San Isidro | ≈ 5 µg/m³ |
| Curridabat | ≈ 8 µg/m³ |
| San Vicente | ≈ 8 µg/m³ |
| San Vicente de Moravia | ≈ 8 µg/m³ |
| San José | ≈ 4 µg/m³ |
| Purral | ≈ 8 µg/m³ |
| Turrialba | ≈ 4 µg/m³ |
| San Miguel | ≈ 8 µg/m³ |
| San Pedro | ≈ 8 µg/m³ |
| San Rafael Abajo | ≈ 8 µg/m³ |
| Quesada | ≈ 4 µg/m³ |
| Cartago | ≈ 8 µg/m³ |
| Chacarita | ≈ 6 µg/m³ |
| San Juan | ≈ 8 µg/m³ |
| Guadalupe | ≈ 8 µg/m³ |
| Aserrí | ≈ 8 µg/m³ |
| San Rafael | ≈ 8 µg/m³ |
| San Felipe | ≈ 8 µg/m³ |
| Patarrá | ≈ 8 µg/m³ |
| Tejar | ≈ 5 µg/m³ |
| Heredia | ≈ 8 µg/m³ |
| San Pablo | ≈ 8 µg/m³ |
| Cañas | ≈ 5 µg/m³ |
| Guápiles | ≈ 5 µg/m³ |
| Siquirres | ≈ 4 µg/m³ |
| San Diego | ≈ 8 µg/m³ |
| Esparza | ≈ 6 µg/m³ |
| San Juan de Dios | ≈ 8 µg/m³ |
| Nicoya | ≈ 4 µg/m³ |
| San Rafael Arriba | ≈ 8 µg/m³ |
Updated 2026-10-01 22:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.