How crop drought is assessed

The US Drought Monitor is not just a satellite map. It is a weekly expert assessment.

The question this tool answers

Food risk has two different meanings on this page. In the United States, we track weekly drought stress in major crop and pasture states: corn, soy, wheat, cotton, sorghum, and cattle country. Globally, we show countries that FAO's Global Information and Early Warning System flags for food-supply concern. The dashboard asks both questions separately: how much US farmland is under severe drought, and where is the global food-security watchlist flashing?

How we know

The live US data come from the US Drought Monitor, a weekly map produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln with NOAA, USDA, and a network of regional experts. Many readers assume the map is a pure satellite product. It is not. It blends precipitation, streamflow, soil moisture, vegetation health, snowpack, groundwater, local reports, and expert judgement into one weekly consensus.

The categories run from D0 to D4. D0 is abnormally dry. D1 is moderate drought. D2 is severe drought, where crop losses become likely and pasture stress becomes material. D3 is extreme drought. D4 is exceptional drought. This dashboard focuses on D2+ because it is a practical agricultural line: severe or worse.

The choices we made

We promote the state grid because national averages hide the story. A 41% lower-48 D2+ number is serious, but the texture matters: Nebraska can be in deep red while Illinois is mostly clear. Each state bar shows the full drought mix from no drought through D4, so readers can see whether a state is mostly moderate stress or contains a true exceptional-drought core.

We add named crops because drought categories are abstract until they land on production systems. Nebraska drought means corn, wheat, and cattle. Oklahoma means wheat and cattle. Texas means cotton, wheat, and cattle. Those labels are context, not a live USDA crop-condition feed.

Why ENSO appears here

El Niño and La Niña are not farm forecasts, but they tilt seasonal odds. La Niña often favors drier conditions in parts of the southern tier and Plains; El Niño can bring relief to some US drought regions while raising risk elsewhere. The dashboard reads NOAA CPC Niño-region data and puts it next to US D2+ drought so readers can see the seasonal climate backdrop.

What FAO GIEWS adds

FAO's Global Information and Early Warning System tracks countries facing crop shortfalls and food-supply stress. Those crises are not simply “drought equals famine.” Conflict, displacement, market prices, currency shocks, pests, floods, and trade restrictions can matter as much as rainfall. That is why the GIEWS layer is curated and labelled as food-security context rather than treated as a global live drought map.

What this tool cannot tell you

It is not a global vegetation or soil-moisture monitor. It does not yet wire NDVI, SMAP soil moisture, the EU Global Drought Observatory, or national crop-condition reports. The live drought time series is US-focused. Outside the United States, the page uses FAO GIEWS country-level warnings, which are broader food-security assessments.

It also cannot predict harvest losses directly. Crop outcomes depend on growth stage, irrigation, soil type, planting decisions, commodity prices, and rainfall timing after the map date. Drought is a risk signal, not a yield model.

Credits

This dashboard depends on the weekly work of USDM authors and regional experts, NOAA ENSO monitoring, and FAO food-security analysts. We download public data, compute rankings and context, and keep the scope visible: US drought is live; global food risk is curated.

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