Crop health · Global NDVI
Open-Meteo ERA5 and NASA POWER data · 16 global grain zones
Last update: 4 May 2026
How to read this chart
Water Balance (WB)
Each day: rainfall received minus water evaporated by the soil. Over 30 days, if the total is negative, the crop lacks water. Positive, it holds on.
WB -40mm over 30 days: the soil loses 40mm more than it receives. At this stage, you can see it in the leaves.
Score 0 to 100
60% water balance + 40% soil moisture, reduced to a single number. 75+, the crop is comfortable. Below 40, it needs watching.
75+ Excellent60 Good45 Average30 DegradedCritical
Alerts
An alert triggers in two cases:
Deficit : WB over the last 14 days below -30mm. Roots start to suffer, yield follows.
Excess : soil above 85% saturation. Roots lack air, fungi proliferate, and machinery cannot enter the field.
Abbreviations glossary
WBWater Balance = precipitation − evapotranspiration (mm/day)
WB 30d30-day cumulative WB, showing the underlying trend
WB 14d14-day cumulative WB (deficit alert if < -30mm)
ET0Reference evapotranspiration (FAO Penman-Monteith): what the soil evaporates in fair weather without water stress
WB sc.Water Balance Score (0-100), calculated on 30-day WB. 0 = severe deficit, 50 = balanced, 100 = maximum surplus
Soil sc.Soil Moisture Score (0-100): compares current moisture to 30-year climatological average (NASA POWER). 50 = within normal range
ScoreFinal health score = 60% WB sc. + 40% Soil sc. A single number summarising crop condition
Soil m.Volumetric soil moisture in the root zone (28-100cm), in % or m³/m³
Sources: Open-Meteo ERA5 (archive) · Open-Meteo Forecast · NASA POWER (30-year climatology) · Daily update 7h UTC