The Crop Monitor sub-national crop calendars are created using various data sources and expert knowledge and broken down into bi-monthly time steps with five phenological phases/stages applicable across most crops.

The Crop Monitor for Early Warning uses a global cropland extent mask from the European Commission JRC Anomaly Hotspots of Agricultural Production (ASAP).

The Crop Monitor for AMIS uses a harmonized set of global crop-specific cropland extent maps for the four major grains developed from the most recent, highest quality existing crop-type maps.

NDVI is a measure of vegetation health that calculates the difference between near-infrared and red light, providing an estimation of the state and/or amount of vegetation with values ranging from -1 to 1, where higher values indicate healthier vegetation.

An NDVI Anomaly refers to the difference between the average NDVI for a specific time period and the average NDVI for the same period over several years, typically used to characterize the health of vegetation and identify unusual changes.

Precipitation is crucial for agriculture as all crops require water to survive and develop, but too much or too little rainfall can be harmful, and its spatial variability makes it an important meteorological parameter to monitor crops.

Precipitation anomalies show deviations from the long-term average, with negative values indicating drought conditions and positive values indicating flooding events, providing crucial information for crop monitoring and yield prediction.

Temperature is a key factor in crop development, with upper and lower limits for crop growth, and temperature fluctuations during the growing season can result in crop losses or yield reductions.

Surface soil moisture is crucial for crop growth and is influenced by various factors like weather, drainage, and soil type. Soil moisture anomalies are used to detect and monitor agricultural drought which can reduce production outcomes.

Evapotranspiration is the combination of evaporation from the land surface and transpiration from plants, which draws water and nutrients up from the soil into the stems and leaves, releasing water vapor into the air through transpiration.

Surface runoff measures the amount of surface water available after evapotranspiration and soil moisture storage, serving as an indicator of available water for agriculture, and total runoff anomalies can indicate flooding or drought conditions.