The city’s 24-hour average concentration of PM2.5 particles reached 160, and the index stood at 153 on Saturday morning, both classified as unhealthy for all groups.
In Alborz Province, monitoring stations reported unhealthy conditions in Savojbolagh for all residents, while Karaj and Nazarabad recorded levels considered hazardous for vulnerable groups including children, the elderly and individuals with heart or respiratory diseases.
Authorities reported PM2.5 readings of 161 in Savojbolagh, 148 in Nazarabad and 123 in Karaj.
Tehran police announced that, due to emergency measures approved by provincial authorities, the odd-even traffic scheme would be enforced citywide.
In Mashhad, air quality remained unhealthy for the 22nd consecutive day, with an average index of 108 over the past 24 hours and peaks of 136, affecting sensitive groups across most monitoring zones.
The National Meteorological Organization forecast a gradual improvement beginning Monday evening with the arrival of a rain-bearing clouds.
In Khuzestan Province, 18 cities reported polluted air, with Hoveyzeh registering a PM2.5 index of 239, classified as “very unhealthy.” Several other cities, including Ahvaz, Shushtar and Susa, were in the red, while Dezpart reported clean conditions.
