City

Average concentration of the days when the regulated limit value was exceeded (µg/m³)

Index calculation algorithm

Results for the air quality index

Condition of the air quality

Agua Prieta

281

I = ((200 − 100)/(441 − 210)) ´ (Average − 210) + 100

131

No satisfactory

Nogales

418

190

Puerto Peñasco

404

184

Hermosillo

278

129

Guaymas

245

115

Obregón

276

129