Idaho’s water system is running on empty and forecasters are now watching the Pacific Ocean for signs of an El Niño that could make next winter just as dry as the historically mild one that left the state with its lowest snowpack on record.

The National Oceanic and Atmospheric Administration’s Climate Prediction Center has issued an El Niño Advisory, confirming that El Niño conditions are present in the tropical Pacific and are expected to strengthen through the winter of 2026-27. By November through January, the agency’s own outlook gives roughly equal odds to a moderate, strong or very strong event — with about a 1-in-4 chance it reaches the “very strong” tier, a threshold crossed only a handful of times since 1950.

El Niño winters tend to follow a predictable script in Idaho: the Pacific jet stream slides south, storms get pulled toward California and the Southwest instead of the inland Northwest, and what precipitation does fall arrives as rain instead of snow at lower elevations. The result is typically a warmer winter, a thinner mountain snowpack, and a shorter window for that snowpack to build before spring melt begins.

That forecast would be unwelcome in any year. This year, Idaho doesn’t have the cushion to absorb it.

A federal report released May 14 by the National Integrated Drought Information System found that April 1 snowpack in Idaho was the lowest on record, with the only winter warmer than 2025-2026 occurring back in 1933-1934. A drought information statement from the National Weather Service office in Pocatello reinforced that picture, confirming moderate to exceptional drought across most of south central and eastern Idaho.

For East Idaho specifically, snowpack was running between just 16% and 35% of normal as of May, according to federal snowpack maps, with peaks and melt-out occurring two to four weeks earlier than usual. River levels are very low across the region, and every basin in southern and eastern Idaho is forecast to see below-normal runoff from April through September, according to the weather service’s Pocatello office. The Bear River, Little Wood River and Willow Creek are forecast at less than half of normal, while the Snake River sits generally between 50% and 70% of normal, with East Idaho’s storage reservoirs already being drawn down earlier than usual.

Local cities are continuing to see historically low rainfall amounts, making the situation even more grim.

Pocatello’s May precipitation was .18 inch, the second lowest ever recorded, while June has seen only .17 inch of rain fall on the Gate City as of Thursday.

Rexburg’s June precipitation as of Thursday is sitting at .06 inch, tying June 2016 for the lowest June precipitation ever in the city.

Idaho Falls has received only .14 inch of rain so far this month, making it the sixth driest June ever there.

Nearly all of East Idaho is now designated under exceptional, extreme or severe drought, with conditions worsening in recent weeks across the Big and Little Lost River basins, the eastern Magic Valley, the Upper Snake River Plain, and parts of Caribou, Bannock, Power, Oneida, Franklin and Bear Lake counties. Thirty-day precipitation has generally run at half of normal or lower regionwide, and May temperatures have run 8 degrees or more above normal across the entire region.

The dry conditions are also accelerating wildfire risk. Fuel moisture for light fuels is well below average and approaching critical levels weeks earlier than normal, and the weather service’s Pocatello office is calling for above-normal significant wildland fire potential across East Idaho in July and August.

Idaho Department of Water Resources Director Mathew Weaver, in an emergency drought declaration he signed April 13, found that the state had just experienced its second-warmest winter since 1896 and that March 2026 ranked as the second-warmest March on record. That warmth accelerated snowmelt beginning March 17, including at elevations above 10,000 feet, where snow typically holds for at least another month, according to the order. By April 1, snowpack across Idaho was the lowest on record: 54 snow course locations and 45 SNOTEL monitoring sites in the Snake River Basin all reported record-low snow-water equivalent values.

Gov. Brad Little approved the statewide emergency declaration the same day Weaver signed it, covering all 44 Idaho counties and authorizing streamlined, temporary changes to water rights through the end of the year to help agricultural users cope. It was the state’s first statewide drought emergency since 2001. Federal forecasters cited in the order projected a 50% chance of irrigation shortages on the Boise and Snake rivers under normal spring conditions, with water supplies already running well below normal in several basins.

That isn’t a one-year anomaly, either. Six of the past 10 years have brought county-level drought emergencies somewhere in Idaho, and some parts of the state have been in drought continuously since 2019.

The consequences have only deepened since spring. In a June 11 press release, the Idaho Surface Water Coalition — which delivers Snake River water to about 550,000 acres of farmland across southern Idaho — laid out just how dire the irrigation season has become.

“Idaho is in a bad situation. The snow never fell this past winter, so now we are dealing with one of the most challenging water years in generations, with the consequences already stacking up,” Surface Water Coalition Chairman Alan Hansten said in the release.

According to preliminary data the coalition cited from Water District 1, the state agency responsible for distributing surface water under Idaho’s priority system, this year’s mountain snowpack came in at less than 40% of typical levels statewide. Reach gains — the natural flow gains the Snake River picks up as it moves downstream — are nearing record lows as well.

Reservoir storage tells the same story. The coalition’s release shows reservoirs currently holding about 2.47 million acre-feet of water, compared with 3.6 million acre-feet at this time last year and roughly 3.25 million in a normal year. That leaves the system about 1.2 million acre-feet short of where it should be — close to a third below normal — or, as the release put it, enough water to fill more than 45,000 football fields all the way to the top of the goalposts.

Those shortages are translating directly into water cuts. The release lists reductions to normal allocations across the coalition’s member districts: Twin Falls Canal Company is down 33.3%, North Side Canal Company and American Falls Reservoir District No. 2 are each down 20%, Minidoka Irrigation District is down 15%, and Milner Irrigation District is down 12.5%.

The human cost is already showing up in the fields. The coalition’s release describes one farmer served by Twin Falls Canal Company who chose to sacrifice an entire grain crop rather than risk losing it outright — chopping the grain early to sell as cattle feed so the water that would have gone to it could instead protect higher-value crops.

“Our members are facing deep cuts to each of their water supplies, which in turn is leaving everyone who relies on our water working hard to stretch their supply,” Hansten said. “Farmers are already having to decide what fields to abandon to make it through the summer. The impacts of this very real drought already equate to lost crops and lost income, and will be felt in our towns, our businesses, our grocery stores, and around kitchen tables across Idaho and our nation.”

The strain isn’t confined to surface water, either. In May, the coalition and nine groundwater districts jointly filed an addendum to a 2024 mitigation plan with IDWR, expanding the same conservation standards, storage obligations and managed-recharge requirements to three additional groundwater districts — the Little Lost River, Big Lost River and Upper Big Lost River basins. Under that agreement, groundwater users with junior water rights agreed to roughly an 11.3% reduction through a combination of pumping cuts and aquifer recharge.

“It’s important that our fellow Idahoans understand the constraints our canal companies, our irrigation districts, our farmers, our ranchers, and all water users are facing,” Hansten said. “Every water user is being asked to do more with less, and they are responding with the same resilience that has always defined Idahoans. The path forward is uncertain, but we will continue to work together to do what is best for the state of Idaho.”

The long-range outlook offers little comfort. The weather service’s Pocatello office has said drought conditions are expected to persist and even deepen across much of the western United States, including all of southern Idaho, with this summer’s outlook calling for below-normal precipitation and above-normal temperatures across the entire region.

That’s exactly why the developing El Niño matters so much heading into next winter. With reservoirs already drawn down to roughly a third below normal and little snowpack left to refill them, water managers have said the real risk isn’t necessarily finishing out this irrigation season — it’s what happens if next winter again fails to meaningfully restock the system before the 2027 season begins.

Forecasters caution that the El Niño’s ultimate strength remains genuinely uncertain this far out, and that even strong events don’t guarantee a bad outcome for every basin or every storm. But for a region already facing what federal officials have called the worst snowpack on record, and a state managing what its own water regulators have called one of the most challenging water years in generations, the stakes riding on next winter’s outcome are higher than usual.

The weather service’s Pocatello office said it plans to issue an updated drought statement in mid-June if conditions change significantly. The Surface Water Coalition said it will continue monitoring conditions and providing updates as the irrigation season progresses.