Irrigation Information Maps Explained:

Rainfall Last Week: Approximately 700 rain gauge sites are used to produce this map that shows the total rainfall (inches) observed over the last 7 days.

Evapotranspiration: Using the Penman Monteith equation, the maps show the total potential evapotranspiration (inches) over the last 7 days. Approximately 200 sites are used to generate this map.

Rainfall Deficit: This maps is simply the difference between weekly rainfall and evapotranspiration. Negative values indicate that evapotranspiration exceeded precipitation. This map is useful for assessing irrigation requirements.