• Data reference period
• Geographic localization (weather station)

• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).
• WEATHER STATION:  Facility where scientific studies are conducted and atmospheric phenomena are observed for the purpose of making weatherforecasts. Information gathered by weather stations and satellites is collated by computers at central departments and mathematical models.
• PRECIPITATION:  Deposition of water on earth from the atmosphere, in the liquid or solid state, resulting in different forms of precipitation - rain, snow and hail - arising from thermohydrodynamic processes that occur in cloud systems.

Total annual precipitation/ Average total precipitation of Climate normal