El Niño’s Growing Threat: A Slower Harvest at Home, A Bigger Problem in Brazil

As combines prepare to roll across the Corn Belt, a rapidly strengthening El Niño is shaping up to be one of the biggest wild cards for both U.S. harvest weather and South America’s upcoming growing season. The warnings have been around for months: this El Niño could be one of the strongest on record. Eric Snodgrass, Senior Atmospheric Scientist for Nutrien Ag Solutions, says the reason farmers need to pay attention is because this El Niño isn’t just strong, it’s on pace to be historic.

“The big question everybody’s trying to answer is how big is this El Niño going to be,” Snodgrass says. “If you look at the El Niño temperatures right now, they’re already way above our biggest El Niños in recent history, like the ones in 1997, 2015 or even 1982.”

(Eric Snodgrass )

That’s not a small claim. The 1997 and 2015 El Niños both rank among the most disruptive weather patterns in modern agricultural history, and Snodgrass says current ocean temperatures are already outpacing both, before the event has even peaked.

The newest data only reinforces that trajectory, according to Snodgrass.

“Take a look at this new forecast that just came out from the European model,” he says. “The strongest we’ve ever seen is about three degrees C, and this is gonna blow past it.”

(Eric Snodgrass)

While that seems intense, Snodgrass says he’s not ruling out an even more extreme outcome.

“There are some forecasts that are taking this maybe even higher than four degrees Celsius,” Snodgrass says. “Not this one from the Europe model, but some are.”

For farmers, the size of this El Niño matters because it’s the engine behind everything else Snodgrass is tracking this fall, from how many field-workable days U.S. growers get during harvest, to whether Brazil and Argentina catch too much rain, too little, or both at the wrong time.

A Wetter, Slower Fall for U.S. Harvest

For farmers hoping for a repeat of the last several dry, fast-moving falls, Snodgrass has a warning: this year is likely to look different.

“Unlike what we’ve seen for most of the last five or six years, where our falls have been epically dry, we’re concerned we’re going to shave off about 20% of our typical fall field workable days by having increased chances of rainfall,” he says.

(Eric Snodgrass)

Snodgrass points to the historical pattern from past strong El Niño years, which shows a low likelihood of a dry fall across most of the country outside of the Pacific Northwest and parts of the Canadian Prairies. The newest European weather forecast, released Aug. 5, backs that up, putting much of the U.S. in a wetter-than-average category as harvest gets underway.

That doesn’t mean the entire country will see relief from summer’s heat and dryness. Snodgrass says Texas, Oklahoma, Arkansas and Louisiana remain the exception, with a ridge of hot, dry weather expected to linger in the southern Plains even as the rest of the country trends wetter.

The forecast comes on the heels of a brutal July for parts of the western Corn Belt. Snodgrass says research shows yield losses accelerate once average high temperatures during silking climb 2.5 to 2.7 degrees above normal, a threshold that was blown past by four and even five degrees in some western Corn Belt locations this summer.

The Bigger Story May Be Brewing in South America

While a slower, wetter U.S. harvest is a manageable headache, Snodgrass says the more consequential impact of this El Niño could unfold thousands of miles south, as Brazil and Argentina head into planting season.

The typical El Niño precipitation pattern in South America splits the continent: wet conditions across southern Brazil, including Paraná and Rio Grande do Sul, and Argentina, paired with drier conditions to the north, including the Cerrado region.

That north-south divide is exactly what the September-November precipitation outlook is showing, according to Snodgrass. And the dry side of that pattern is layering on top of an already-established climate trend.

“Since we’ve looked since the ‘80s and ‘90s, the total amount of precipitation in that [Cerrado] box... is suggesting we’re down about three inches on average compared to those earlier decades,” Snodgrass says. “So they’re already seeing a drying trend, which is pushing them later and later into their planting. And the more delays they have there, the bigger impact it’s going to have on U.S. markets.”

(Eric Snodgrass)

Mato Grosso, Brazil’s top soybean-producing state, carries enough production capacity to absorb some rainfall shortfalls, Snodgrass notes, but he points out the real question is timing on both ends of the pattern.

“Does this precipitation pattern slow the North down with not enough early rainfall in October, and then slow the South down with too much rainfall in September and October to get them really going?” Snodgrass says. “I think it’s the crop calendar we need to watch more than anything else at this point.”

(Eric Snodgrass)

Brazilian Growers Signaling Caution on Acreage

Snodgrass says a conversation earlier this week with a group of Brazilian growers who visited Nutrien reinforced his concerns, but also surfaced a second issue that could carry even more weight for U.S. farmers.

“They’re concerned about the same thing I just shared with you, and they’re also concerned because, unlike the past decade, right now the sentiment among Brazilian growers is to not increase acreage in the 2026-2027 growing season,” Snodgrass says. “That’s huge for United States farmers. We just need to keep an eye on this going forward.”

(Eric Snodgrass )

With global grain supplies already tightening, a combination of planting delays, uneven rainfall and flat-to-lower Brazilian acreage could shift more attention, and more market weight, back onto U.S. production in the months ahead.

“I’m concerned about it. We just need to keep an eye on this going forward,” says Snodgrass.