Jakarta Records Improved Air Quality on First Day of JRF 2026

The Jakarta government rolled out Weather Modification Operations (OMC) starting Wednesday (10/21), bringing cooler morning temperatures and lower pollutant levels across the capital's five administrative cities on the opening day of the Jakarta Running Festival (JRF) 2026 on Saturday (10/24).

Multiple meteorological factors may be at play here, including cloud seeding efforts

Jakarta Environment Agency Head Dudi Gardesi noted that readings from Air Quality Monitoring Stations (SPKU) on Saturday (10/24) pointed to falling pollutant levels citywide.

Agency data revealed that PM2.5, PM10, and sulfur dioxide levels dipped on Saturday morning, with the most pronounced drop recorded between 4 AM and 7 AM.

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South Jakarta saw PM2.5 concentrations decline to between 12 and 32 micrograms per cubic meter (µg/m³) from 4 AM to 5 AM, safely under the national standard of 55 µg/m³.

Coastal North Jakarta saw PM2.5 levels plunge to between 9 and 17 µg/m³ from 4 AM to 7 AM.

Similar downward trends swept West, East, and Central Jakarta, with Central Jakarta logging morning PM2.5 and PM10 concentrations between 12 and 43 µg/m³.

Dudi noted that falling pollutant levels stem from a mix of meteorological dynamics, local emission patterns, and OMC effects. Rainfall triggered by cloud seeding helps clear atmospheric particulate matter through wet deposition.

“Multiple meteorological factors may be at play here, including cloud seeding efforts. Still, deeper analysis is needed to quantify the impact of each variable and assess whether these air quality gains will last,” he explained.

Jakarta Regional Disaster Mitigation Agency (BPBD) Acting Head Marulitua Sijabat noted that cloud-seeding sorties aimed to maximize rain potential and improve atmospheric comfort for residents and more than 37,000 JRF runners hailing from 48 nations.

“In line with our expectations, the capital enjoyed cleaner, cooler air on the festival's opening day. We're closely tracking weather patterns with BMKG to keep our cloud-seeding deployments precise,” he emphasized.

BPBD records show that four cloud-seeding sorties were flown from October 21 to 23 using a PK-SNH aircraft carrying sodium chloride (NaCl) agent. The seeding missions focused on Bogor, Depok, Bekasi, and South Jakarta.

These flights successfully induced varying degrees of rainfall around the greater capital area. By Friday (10/23), light-to-moderate showers swept parts of South Jakarta, East Jakarta, Depok, Bogor, and South Tangerang.

Alongside weather modification, the city sprayed water mist along key stretches of the JRF 2026 marathon course. Joint teams from the Central and South Jakarta Environment Sub-agencies and the Jakarta Fire and Rescue Agency led the effort to cool down the route and boost comfort for participants.

BPBD and BMKG remain on standby, tracking weather patterns to guide further operational decisions ahead of the festival's second day on Sunday (10/25).

Participants echoed positive feedback on the race environment. South Jakarta runner Dwi praised the cooler morning climate, noting it made for a far better running experience.

“It felt surprisingly cool this morning, which really helped during the run. The water mists along the course were a great touch, especially when it got busier and warmer,” Dwi added.