The year 2017 is classified as extremely hot and the average air temperature will be about +1.1°C higher than the normal value corresponding to the 2nd warmest year since 1931 (the hottest was 1997). It should be noted that the 5 warmest years have occurred in the last 30 years. The maximum temperature in 2017, about +2.4°C higher than normal value, will be the highest value since 1931, surpassing by about 1°C the previous higher value (1997, +1.38°C anomaly). The average annual minimum temperature value will be close to 1971-2000 normal.
The year 2017 was extremely dry and will be among the 4 driest since 1931 (all occurred after 2000). The average annual total precipitation will be around 60% of normal. The period from April to December, with persistently negative monthly precipitation anomalies, will be the driest of the last 87 years.
Throughout this year, the combination of persistently lower than normal precipitation values with much higher than normal temperature values, in particular the maximum temperature resulted in high evapotranspiration values and significant values of ground moisture deficit. On December 27, although soil water values increased in relation to the end of November, they are still below 40% in central and southern regions of the country.
At the end of December the situation of meteorological drought remains, although regarding the situation on November 30, there has been a decrease in intensity in northern and central regions. In central and southern interior regions precipitation values were much lower than normal and insufficient for an effective reduction of drought intensity.
According to Palmer Drought Severity Index (PDSI) in December there was a decrease in the intensity of meteorological drought, with around 60% of the territory (regions south of Montejunto-Estrela Mountain) in classes of severe and extreme drought.