September 2026 was the hottest September in mainland Spain since records began in 1961, according to the Spanish State Meteorological Agency (AEMET). The month's average temperature reached 22.5°C, standing 3.4°C above the 1991–2020 reference average and surpassing the previous September record, set in 1987, by 0.7°C.

The exceptional warmth extended to the Balearic Islands, where the average temperature reached 24.5°C, or 2.2°C above normal. Ibiza and Formentera also experienced unusually high temperatures and significantly below-average rainfall, according to AEMET data reported locally.

The agency's monthly climate summary, published on 16 October, classified September as extremely warm across mainland Spain and very dry in terms of mainland rainfall.

Record-Breaking Temperatures Across Mainland Spain

The national temperature figures highlight the scale of September's exceptional heat. For the first time in the historical series, a September's average temperature in mainland Spain exceeded the reference average for the summer as a whole, which stands at 22.1°C for the 1991–2020 period.

The heat was widespread, although some areas in the northwest experienced conditions classified as very warm rather than extremely warm.

A heatwave affected mainland Spain and the Balearic Islands from 2 to 7 September. In the Canary Islands, three separate heatwaves occurred during the month, between 7 and 9 September, 14 and 16 September, and 24 and 27 September.

The highest temperatures recorded at AEMET's main weather stations included 44.4°C at Morón de la Frontera in Seville province on 3 September and 44.0°C at Seville Airport on the same day. At 17 main weather stations, September's maximum temperature was the highest recorded in their respective historical series.

Ibiza and Formentera Also Experienced Exceptional Heat

The Pitiusan islands recorded average temperatures well above their usual September levels.

In Ibiza, the average temperature was 24.6°C, which was 1.8°C above normal. Formentera recorded an even higher average of 25.6°C, representing an anomaly of 2.2°C.

Sant Joan de Labritja experienced its hottest September since records began at the local station, with an average temperature of 24.3°C. The highest temperature recorded in Ibiza during the month was 39.2°C on 6 September, while Formentera reached 36.1°C on 7 September.

Night-time temperatures also remained high. Minimum temperatures reached 23.9°C at Ibiza Airport and 24.2°C in Formentera, while the islands recorded 15 and 17 tropical nights respectively.

These figures show that the exceptional warmth was not limited to daytime highs, with elevated overnight temperatures also contributing to the month's unusual conditions.

Rainfall Remained Well Below Normal

Despite several episodes of intense rainfall elsewhere in Spain, September was very dry overall across mainland Spain.

AEMET recorded just 15.9 millimetres of precipitation across mainland Spain, equivalent to 36% of the 1991–2020 average. It was the seventh-driest September in the series beginning in 1961 and the third-driest of the 21st century.

The Balearic Islands recorded 46.9 millimetres of rainfall and were classified as dry. In Ibiza, approximately 10 millimetres fell during the month, compared with a typical September average of 76 millimetres. Formentera recorded around 10 millimetres against a usual average of 44 millimetres.

The contrast between the wider Spanish rainfall figures and the conditions in the Pitiusan islands underlines the importance of looking at regional data when assessing the month's weather.

What the September Climate Figures Show

AEMET's figures establish September 2026 as a record-hot month for mainland Spain, while the Balearic Islands experienced temperatures substantially above their seasonal averages and dry conditions.

The data also illustrate the value of distinguishing national records from local observations. Although mainland Spain's temperature record is the headline finding, the figures for Ibiza, Formentera and the wider Balearic Islands provide a clearer picture of how the exceptional September weather affected the archipelago.

The agency's monthly summary confirms the scale of the temperature anomaly and the lack of rainfall across much of Spain, with local figures showing that Ibiza and Formentera were also affected by persistent warmth and unusually dry conditions.