Experimental technology called cloud seeding used to produce more rain in Arizona

PHOENIX — A new experimental technology called cloud seeding was used successfully to produce more rain in Pinal County last year.

About 30 cloud seeding tests were done between July and September 2025 in the active management area, which is in the western part of the county, and produced an increase of about 34,000 acre-feet of rain, according to Pinal County Water Augmentation Authority Executive Director Joe Singleton.

“Cloud seeding is taking artificial means to try to induce rainfall that you otherwise may have not naturally got out of a cloud,” Singleton told KTAR News 92.3 FM. “Rain clouds aren’t always as efficient as they could be and cloud seeding encourages them to give up more moisture than they might have otherwise.”

How the cloud seeding agents work

Cloud seeding works by shooting a seeding agent out of a flare on a small plane directly into the cloud.

The authority chose not to use the glaciogenic seeding agent, which includes silver iodide, after objections from the Tohono O’odham Tribal Nation. Instead, they opted for the hygroscopic seeding agent.

“Which kind of attracts and holds moisture in the seeding agent and encourages water droplets to get bigger and hopefully heavy enough to fall,” Singleton explained.

The hygroscopic seeding agent is similar to the fertilizer chemical potassium chloride.

“There’s no credible studies anywhere that show that these seeding agents that we use, or that have been being used over the last decades, do cause a health hazard,” Singleton said.

Opposition due to flooding and environmental concerns

There were questions at a December 2025 meeting of the Arizona House Committee on Natural Resources about whether the cloud seeding caused flooding in Maricopa.

Singleton stated that the flooding in Maricopa happened two days after they seeded in the southeastern part of Pinal County, meaning they were not seeding near Maricopa and too much time had passed.

As for allegations that cloud seeding produces chemical trails, also known as chemtrails, Singleton said the small planes used don’t produce them.

He added that if they did cloud seeding again, there would be better public outreach to ensure the community knows more about the process and when it’s happening.

How much does cloud seeding cost?

The project cost nearly $220,000 to execute and with roughly 34,000 acre-feet of rain produced, that comes out to a water cost of roughly $6.50 an acre foot, which is well below the average cost of what other municipalities pay for water.

Singleton said the county used their own monies for the project, adding he’d like to do more cloud seeding there but would have to find additional funding.

While Pinal County was the first to get a license for cloud seeding from the Arizona Department of Water Resources, Singleton claimed there are other municipalities who are interested in making it rain.

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