Rainfall and temperature

The "Rainfall and temperature" fact sheet examines the variation of annual rainfall and temperature averages in relation to the average values occurred in the 1971-2000 period.

Rainfall performs a vital role in agriculture, public water supply, energy production, industry, tourism and natural ecosystems. Together with temperature, it is one of the most important indicators for characterising the climate of a given region.

The average annual air temperature at the surface of the earth is an essential indicator for assessing the state of the environment: besides being one of those monitored for more years, it is also the main indicator for monitoring climate change. The increase in temperature, largely due to the emission of greenhouse gases, affects, inter alia, the sea level, the intensity and frequency of floods and droughts, the species and the habitats, the yield of agricultural crops and infectious diseases.

As agreed upon by the World Meteorological Organizationthe climate is characterised by the average values of the various climatic elements over a period of 30 years, a number of years long enough to represent the average value of that parameter at a given place (climatological normal).

Extreme events relative to temperature include heat waves (occurring when, for an interval of at least 6 consecutive days, the maximum air temperature (daytime high temperature) is 5°C above the average daily maximum temperature in the reference period) and cold spells (occur when, for a period of at least 6 consecutive days, the minimum air temperature is 5°C below the average daily minimum in the reference period).

This fact sheet shall be updated on an annual basis and concerns mainland Portugal.

Objectives and targets: 
  • To monitor variations in rainfall and temperature patterns, taking into account the objective of the 7th Environmental Action Program to limit the increase in the global average temperature of the Earth's surface to 2°C, compared to pre-industrial levels.
Progress analysis:
Last update: 
Friday, 15 October, 2021