According to an analysis of the climatological situation in January, published on the IPMA website, from the 22nd until the end of the month, air temperature values “much higher than the monthly average value” were recorded.

The heat wave covered around 30% of the continent's meteorological stations, explains IPMA, noting that heat waves in Portugal in the month of January are rare.

“It should be noted that, of the approximately 60 meteorological stations analysed since 1941, 75% of the stations never recorded a heat wave this month”, explains the document.

The highest number of heat waves in January was recorded in high-altitude stations, with Penhas Douradas experiencing seven heat waves since 1941, two of them in 2015. Bragança and Portalegre recorded two heat waves each.

A heat wave occurs when the maximum daily temperature is at least 5ºC (degrees Celsius) higher than the average value for that period, for at least six consecutive days.

In January, Penhas Douradas had 13 days of heat wave, extending to this month, Viseu, Cabril and Dunas de Mira 11 days, and Montalegre, Anadia and Coimbra 10 days.