This generalised rise in temperature accompanied by a decrease in relative air humidity will contribute to a worsening of the danger of rural fires, especially in the Algarve in the interior regions, according to meteorologist Ângela Lourenço, from the Portuguese Institute of the Sea and Atmosphere (IPMA).

From Friday onwards, the weather on the continent will be influenced by an “intense anticyclonic ridge located over Western Europe, associated with the transport of a mass of hot and dry air, originating in North Africa”.

“This episode of hot weather in mainland Portugal will be felt mainly from the 29th and 30th [Friday and Saturday]. So far, maximum temperature values above the average close to or exceeding 30 degrees have been recorded in some regions of the country,” she said.

However, from Friday and Saturday, there will be a significant increase, which will result in maximum temperatures, particularly in the southern region and the Tagus Valley, reaching values between 35 and 37 degrees.

“These values are above normal values for the month of September. Although absolute maximum temperature values comparable to episodes occurring during the hottest months are not expected, the predicted values correspond to anomalies of up to around 5 to 8 degrees above the usual average values for this time of year”, he highlighted.

Tropical nights

With regard to minimum temperatures, Ângela Lourenço said that they will register an increase, with nights with values equal to or greater than 20 degrees possible, which the IPMA characterizes as tropical nights, in some places, especially on the coast of the Algarve region.

“This hot weather situation is expected to persist until the beginning of the week, until the 3rd. From then on there is some uncertainty as to whether this persistence of high temperatures will continue or not. In any case, even if there is a drop in temperature, the values will remain above average for the time of year,” she said.

According to Ângela Lourenço, if the scenario of the influence of the anticyclonic crest persists and the episode of hot weather continues for longer, especially in the South region, a heat wave could occur.