Drought Information Statement for South Central and Eastern Idaho
Valid Aug 14, 2026
Issued By: National Weather Service Pocatello Weather Forecast Office
Contact Information: nws.pocatello@noaa.gov
This product will be updated in late September, 2026 if drought conditions change significantly.  
Please see all currently available products at https://drought.gov/drought-information-statements.
Please visit https://www.drought.gov/drought-status-updates for regional drought status updates.
Moderate to exceptional drought exists across most of south central and eastern Idaho
Continued pattern of low precipitation and warm temperatures; multi month rainfall deficit; natural stream levels are well below normal.
Water supply forecasts for most rivers are 60-70% of normal. 
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U.S. Drought Monitor
Link to the latest U.S. Drought Monitor for South Central and Southeast Idaho

Drought intensity and Extent
D4 (Exceptional Drought): Much of Cassia County
D3 (Extreme Drought): Eastern Magic Valley, and Upper Snake River Plain; Eastern Highlands. 
D2 (Severe Drought): Custer, Blaine, Butte, Clark, Fremont, Caribou, Franklin, Bear Lake Counties.
D1 (Moderate Drought): Western Custer and northern Blaine Counties.  
D0: (Abnormally Dry): northwest Custer County

Recent Change in Drought Intensity
Link to the latest 4-week change map for South Central and Southeast Idaho

Four Week Drought Monitor Class Change. 
Drought Worsened: Lincoln County 
No Change: The remainder of the forecast area



Precipitation
As of mid August, 30-day precipitation has been from convective storms that are limited in spatial extent. Bands of above normal precip have occurred from Cassia County northeast through Power, Bannock, Bingham and Caribou Counties; as well as Custer County.   
The remainder of the area has had below normal precipitation. 

Temperature
7-day maximum temperatures above normal for the entire region.   
30-day maximum temperatures were above normal, particularly the SE corner of the state, and much of Blaine and Custer Counties. 

Summary of Impacts
Links: See/submit Condition Monitoring Observer Reports (CMOR) and view the Drought Impacts Reporter
Hydrologic Impacts 
Heavy drafting of reservoir storage; many small reservoirs are depleted (Magic, Oakley); reservoir carryover expected to be very poor.   
Late summer streamflows are well below normal, particularly in unregulated, natural flowing rivers/streams, particularly in low elevation basins with no upstream reservoir storage (Goose Creek, Raft, Malad and Upper Blackfoot Rivers) 

Agricultural Impacts
Streamflow volume forecasts remain well below normal for all Snake River segments; ranging from 50-70%. 
Snake River reservoir system is very low; current system storage at 24% of capacity, 42% of average, and 1.32 million acre feet below average storage for mid August.  

Fire Hazard Impacts
Above normal Significant Wildland Fire Potential Outlook for August and September 



Agricultural Impacts - Water Supply Forecast
Runoff volume forecasts (through September) remain below normal for every river basin in southern and eastern Idaho. 
Forecasts are particularly low for Willow Creek (11%), Little Wood River (50%), and the Bear River (20%).  
Low winter carryover, heavy early year withdrawals and warm summer temps have drafted Snake River reservoirs to levels well below average.   


Fire Hazard Impacts
The Significant Wildland Fire Potential Outlook for August, and September is “above normal” for southern and eastern Idaho. 




Link to Wildfire Potential Outlooks from the National Interagency Coordination Center.

Seven Day Precipitation Forecast
The 7-day precipitation forecast calls for light precipitation for the southern half of the forecast area (up to 0.1” in valleys, up to ½” in mountains). 
Forecasts for the north and eastern parts of the region are for moderate precipitation, including; 
Up to ¼” in valley locations
Up to ½” in the Island Park area.
Up to 1 ½ ” in the Teton foothills, Big Hole Mtns, Lost River, Pioneer, and Lemhi Ranges.  



Long-Range Outlooks
The latest monthly and seasonal outlooks can be found on the CPC homepage
Seasonal outlook probabilities are for a slight probability of above normal precipitation for the SE part of the forecast area; near normal precip for the remainder.  
The temperature outlook is for above normal for the entire region.  


Drought Outlook
The latest monthly and seasonal outlooks can be found on the CPC homepage
Drought conditions are expected to improve for most of the region, and end in much of the central Idaho mountains. 
Links to the latest:
Climate Prediction Center Monthly Drought Outlook 
Climate Prediction Center Seasonal Drought Outlook