The Environmental Management Bureau 7 reported that air quality at monitoring stations in Talisay City and Toledo City returned to "good" levels by 3 p.m. on Friday, July 10, 2026, a day after ash from Mt. Kanlaon reached parts of Cebu. However, officials warned that volcanic gases could still mix with rain, potentially creating acid rain.
Air Quality Readings Improve
At the Talisay station, the PM2.5 concentration was 18.2 micrograms per cubic meter, equivalent to an Air Quality Index (AQI) of 36. Its PM10 concentration was 27 micrograms per cubic meter, with an AQI of 25. Both readings fell within the good category (AQI 0-50), indicating low levels of fine and coarse particles.
The Therma Visayas Inc. (TVI) station in Toledo City recorded even lower particle levels. Its PM2.5 concentration was 4.4 micrograms per cubic meter, with an AQI of nine, while its PM10 concentration was 13 micrograms per cubic meter, with an AQI of 12.
On Thursday, the Talisay station recorded PM2.5 AQI readings of 65 at 8 a.m. and 57 at 4 p.m., both within the fair category. The drop to 36 by Friday afternoon showed a decline in fine-particle pollution. The TVI station maintained good readings throughout.
"Current telemetry data shows that despite lingering volcanic emissions, the local air quality remains within the thresholds," EMB 7 said in a statement.
Why Toledo Received More Ash
Provincial Disaster Risk Reduction and Management Office head Dennis Pastor said Toledo City was the most affected area because it directly faces Mt. Kanlaon and lies in the path of prevailing winds. The winds also carried ash toward Balamban, Pinamungajan, and Aloguinsan in Cebu's third district.
Atmospheric simulations showed volcanic emissions moving eastward over central Cebu as winds blew from the south-southwest. Phivolcs earlier explained that wind and atmospheric conditions determine where ash and volcanic materials travel, not the weather causing eruptions.
Mt. Kanlaon Remains Under Alert Level 2
In its 5:15 p.m. bulletin on Friday, July 10, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Mt. Kanlaon showed no significant increase in activity after the eruption. Alert Level 2 remains in effect, indicating increased volcanic unrest. Phivolcs said the alert level could be raised if volcanic activity increases or explosive eruptions become more frequent.
Risk of Acid Rain
While rain may help remove ash particles from the air, EMB 7 warned that sulfur dioxide carried over parts of Cebu could mix with moisture and create acid rain. The bureau did not report confirmed acid rain in Cebu.
"While the rain likely helped suppress the ashfall, it also carries the risk of creating acid rain," EMB 7 spokesperson Cindylyn Pepito said.
Phivolcs Director Teresito Bacolcol added that rainfall and winds affect how quickly ash settles or moves away. Typhoon Inday and the southwest monsoon were influencing the country when Mt. Kanlaon erupted Thursday morning, affecting where volcanic emissions traveled.
Health Reports and Precautions
Provincial Health Office head Sheila Faciol said two outpatient respiratory cases were recorded at Barili District Hospital and Jose Maria V. Borromeo Memorial Hospital in Pinamungajan since Thursday. Both patients were treated and released.
EMB 7 advised residents to avoid unnecessary exposure to rain while volcanic emissions remain. "If you get caught in the rain, bathe and rinse your skin and hair thoroughly with clean water as soon as possible," the bureau said. Residents should cover open water containers, rain barrels, and deep wells to prevent contamination, and keep doors and windows closed to block residual ash. Sensitive plants should be sheltered or their leaves rinsed with clean water after rainfall.
Weekend Weather Outlook
Pagasa Visayas weather specialist Mark Gales said the rain over Cebu on Friday was caused by the southwest monsoon, not localized thunderstorms. He said Cebu would experience fewer rains over the weekend compared with Friday's downpours in Toledo, Balamban, Compostela, and Tabuelan.
"Central Visayas is OK now. The weather condition will start improving," Gales said. Temperatures are forecast to range from 25 to 30 degrees Celsius on Saturday, July 11, and from 26 to 32 degrees Celsius on Sunday, July 12. Heat index values are expected to range from 33 to 41 degrees Celsius, within the extreme caution category. Moderate to rough seas are still expected due to the winds.
