Last month was the second hottest October in mainland Portugal since 1931, having been very hot and dry, according to the most recent monthly climatological bulletin from the Portuguese Institute of the Sea and Atmosphere (IPMA) released this Thursday, November 27th.
According to IPMA, in October, the average value of the average air temperature was 19ºC, +2.21ºC than the normal value in the reference period of 1991-2020.
The average minimum temperature was 13.42ºC, the sixth highest since 1931, “with an anomaly of +1.80ºC in relation to the normal value”, while the average maximum temperature was 24.57ºC, +2.61ºC compared to the normal value.
The bulletin highlights that the maximum temperature value was above the monthly average value until the 19th and the minimum temperature value until the 25th.
In the minimum temperature, between the 19th and 24th, there were “deviations greater than 3ºC” and “new extremes of the highest value” in Portel and Mértola.
IMPA recorded a heat wave from October 10th to 19th in around 60% of meteorological stations, covering the North, Center and Alto Alentejo regions.
As for rainfall, the monthly total was 86.4 mm, corresponding to 79% of the average value from 1991-2020.
On the 28th and 29th there were “high values of daily precipitation” in the Lisbon and Algarve regions and on the 31st in the Center and North coast regions.
On October 31, more than half (66%) of the continental territory was in mild to severe drought, with a decrease in the North and Center regions and worsening in the Center-South and South regions.
Globally, last month was the third hottest October on record, with an average surface air temperature of 15.14°C.
October was, since April, the first month in 2025 with a temperature above 1.50ºC, the defined limit for the planet’s warming, registering 1.55ºC above the estimated average for the period 1850-1900 (pre-industrial level).