{"id":"us-drought-status","slug":"us-drought-status","name":"United States Drought Status Dataset","description":"The weekly official assessment of where the United States is in drought and how severely, for the country and for each state, from 2000. An expert judgement published by named agencies — which is a different kind of thing from the drought indices Hydrionis calculates, and is held apart from them.","methodology":"Collected from the United States Drought Monitor, produced weekly by the National Drought Mitigation Center with the Department of Agriculture and NOAA. A rotating author combines precipitation, soil moisture, streamflow, reservoir and snowpack indicators with reports from a network of local observers and draws the map; that judgement is what distinguishes it from any computed index. The published shares are cumulative by design — the figure for a category includes every area in a more severe one — and Hydrionis stores them as published rather than converting them into exact bands, because converting would put a Hydrionis-computed number under a name readers know from the publisher. The national request answers with two areas for every week, the contiguous states and the whole country including Alaska, Hawaii and Puerto Rico; the area is named in the request rather than inferred, and the whole country is the one stored against the United States.","domains":["drought"],"metricIds":["drought-area-abnormally-dry","drought-area-moderate","drought-area-severe","drought-area-extreme","drought-area-exceptional"],"subjectScope":"The United States and each of the fifty states","cadence":"weekly","version":"1.0.0","released":"2026-08-31","changelog":[{"version":"1.0.0","date":"2026-08-31","summary":"First release: official drought status, held apart from the calculated indices.","additions":["Weekly area in each Drought Monitor category for the United States and all fifty states, from January 2000.","Fifty state geographies, which Hydrionis did not previously hold."]}],"limitations":["An assessment, not a measurement and not a legal declaration. A category on the map is not a statement that any authority has declared a drought or imposed a water restriction; those are separate acts by separate bodies, and Hydrionis holds neither.","The categories are cumulative as published. Read as exact-category shares they understate every drought — a state 40% in extreme drought and 9% in exceptional is 40% in extreme-or-worse, not 49%.","This is a share of land area, which is not a share of people, farmland or water supply. A state can be most of the way into drought by area with most of its population unaffected.","The map is drawn by an author each week using judgement. That is its strength over a single index and it also means it is not reproducible from any formula, and two authors need not have drawn the same line.","Hydrionis does not derive a drought status of its own and nothing in its calculated indices should be read as one."],"context":{"hydrionisClass":"water-driver","whyHeld":"A drought is not a measurement of water; it is a judgement about a shortage of it, made by people who weighed several measurements together. Hydrionis holds this because it is the answer to \"was this a drought?\" that does not come from Hydrionis — the authoritative outside view against which its own rainfall, flow, snowpack and reservoir records can be read. It is deliberately not a substitute for those records, and they are deliberately not a substitute for it.","waterRelevance":["Whether a low-flow period was recognised as a drought at the time","Reservoir drawdown and the conditions surrounding it","Groundwater and the slow recovery that follows a drought","Snowpack failure as a cause of drought in the mountain west","Water restrictions and the conditions that preceded them"],"suitableUses":["Placing a river, reservoir or snowpack record beside the drought status of the same place and week","Comparing the severity or duration of droughts in one place over the twenty-five years the record covers","Identifying the weeks a drought was at its worst, as a starting point for looking at what the water was doing"],"unsuitableUses":["Treating a category as a legal declaration, a water restriction, or an emergency order — the Monitor is none of those","Adding the categories together, which double-counts, because each already contains the ones more severe than it","Reading a share of land area as a share of people or of water supply affected","Deriving a drought status for anywhere Hydrionis holds indices but no Monitor coverage"],"joinDimensions":[{"kind":"same-administrative-geography","on":"The state or the country the assessment covers, matched to the Hydrionis place of the same name","limitation":"A state is a large and hydrologically mixed area. A gauge inside a state that is 60% in drought may sit in the wet 40%, and the status of the state says nothing certain about the catchment above that gauge."},{"kind":"time-only","on":"Shared weekly periods, coarsened to months where the other series is monthly","limitation":"A drought status and a hydrological measurement can move at different speeds. Rainfall can recover while groundwater stays low, so agreement or disagreement between them in a given week is information rather than a check on either."}],"relationshipConfidence":"contextual","eligibility":{"api":true,"download":true,"overlay":true,"publicPage":false}},"observationCount":354705,"seriesCount":255,"subjectCount":51,"from":2000,"to":2026,"sourceIds":["us-drought-monitor"],"units":["%"],"redistributable":true,"commerciallyReusable":true,"citation":"Hydrionis (2026), United States Drought Status Dataset, version 1.0.0. Retrieved from https://hydrionis.com/data/datasets/us-drought-status/","downloads":[{"file":"/downloads/observations-drought-us-drought-monitor.csv","format":"CSV","label":"drought observations from US Drought Monitor (354,705 rows)"}],"apiPath":"/api/v1/datasets/us-drought-status.json","lastFetched":"2026-08-31","fields":[{"id":"drought-area-abnormally-dry","name":"Abnormally dry or worse, share of area","definition":"The share of an area assessed by the United States Drought Monitor as being in D0 conditions or any more severe category.","unit":"%","nativeGeography":["country","region"],"comparabilityNotes":"This is an assessment, not a measurement and not a legal declaration. The Drought Monitor is produced weekly by author agencies who combine several indicators with reports from local observers, so it carries expert judgement that no single index does — and it is not a statement that any authority has declared a drought or imposed a restriction. It describes the share of *land area*, which is not the share of people, farmland or water supply affected: a state can be 80% in drought by area with most of its population unaffected."},{"id":"drought-area-moderate","name":"Moderate drought or worse, share of area","definition":"The share of an area assessed by the United States Drought Monitor as being in D1 conditions or any more severe category.","unit":"%","nativeGeography":["country","region"],"comparabilityNotes":"This is an assessment, not a measurement and not a legal declaration. The Drought Monitor is produced weekly by author agencies who combine several indicators with reports from local observers, so it carries expert judgement that no single index does — and it is not a statement that any authority has declared a drought or imposed a restriction. It describes the share of *land area*, which is not the share of people, farmland or water supply affected: a state can be 80% in drought by area with most of its population unaffected."},{"id":"drought-area-severe","name":"Severe drought or worse, share of area","definition":"The share of an area assessed by the United States Drought Monitor as being in D2 conditions or any more severe category.","unit":"%","nativeGeography":["country","region"],"comparabilityNotes":"This is an assessment, not a measurement and not a legal declaration. The Drought Monitor is produced weekly by author agencies who combine several indicators with reports from local observers, so it carries expert judgement that no single index does — and it is not a statement that any authority has declared a drought or imposed a restriction. It describes the share of *land area*, which is not the share of people, farmland or water supply affected: a state can be 80% in drought by area with most of its population unaffected."},{"id":"drought-area-extreme","name":"Extreme drought or worse, share of area","definition":"The share of an area assessed by the United States Drought Monitor as being in D3 conditions or any more severe category.","unit":"%","nativeGeography":["country","region"],"comparabilityNotes":"This is an assessment, not a measurement and not a legal declaration. The Drought Monitor is produced weekly by author agencies who combine several indicators with reports from local observers, so it carries expert judgement that no single index does — and it is not a statement that any authority has declared a drought or imposed a restriction. It describes the share of *land area*, which is not the share of people, farmland or water supply affected: a state can be 80% in drought by area with most of its population unaffected."},{"id":"drought-area-exceptional","name":"Exceptional drought or worse, share of area","definition":"The share of an area assessed by the United States Drought Monitor as being in D4 conditions or any more severe category.","unit":"%","nativeGeography":["country","region"],"comparabilityNotes":"This is an assessment, not a measurement and not a legal declaration. The Drought Monitor is produced weekly by author agencies who combine several indicators with reports from local observers, so it carries expert judgement that no single index does — and it is not a statement that any authority has declared a drought or imposed a restriction. It describes the share of *land area*, which is not the share of people, farmland or water supply affected: a state can be 80% in drought by area with most of its population unaffected."}]}