The Singapore skyline is shrouded in smog due to wildfires raging in Indonesia on Oct. 15. | AFP-JIJI

Cloud-seeding missions in the skies above Southeast Asia have done little to snuff out wildfires or disperse the haze that’s cloaked the region for months, exposing the limitations of attempts to modify the weather.

Between them, Indonesia and Malaysia have conducted more than 100 operations this year in an attempt to engineer rain to combat extreme dryness — exacerbated by El Nino — that has parched soils across the islands of Sumatra and Borneo. Toxic smog from the worst wildfire season in a decade has disrupted oil palm harvests, forced schools to close and reduced air quality to unhealthy levels in neighboring Singapore and Kuala Lumpur.

But the costly missions — which even included the use of dry ice to break up areas of warm air that trap smog near the ground — have so far brought little in the way of lasting results.…