Timaru is eight days short of reaching last year's tally of 30 high-pollution days, with no relief in sight.
Timaru experienced its 22nd day of high PM10 this year on Sunday, with a 24-hour average concentration of 75 micrograms of suspended particulate per cubic metre of air, measured at the air-monitoring site in Anzac Square.
Last month, the highest PM10 concentration was recorded on June 4, with a 24-hour average of 104mcg.
At the same time last year, Environment Canterbury (ECan) had recorded 14 days of high pollution in the Timaru airshed.
The highest level of PM10 in the past 10 years was recorded on June 20, 2006, with a 24-hour average concentration of 192mcg.
Temperatures are forecast to get much colder this week, with a southwesterly flow expected, according to MetService meteorologist Peter Little.
"It is going to get colder for Timaru, with snow expected around 500 metres. There is not much rainfall expected this week and the southwesterly will stay for the most of the week," Little said.
"It might hail on Thursday, with a high of 7 to 9 degrees expected on Wednesday and Thursday."
- The Timaru Herald