| City | Total days with valid samples | Days above the maximum permissible limit (210 µg/m3) | Percentage of days over the maximum permissible limit |
| Agua Prieta | 20 | 6 | 30.0 |
| Nogales | 49 | 38 | 77.6 |
| Puerto Peñasco | 38 | 29 | 72.5 |
| Hermosillo | 50 | 3 | 6.0 |
| Guaymas | 32 | 1 | 3.1 |
| Obregón | 34 | 21 | 61.8 |