September was exceptionally warm in the Canary Islands, recording an average temperature of 24.4ºC, 2.6ºC above the historical norm, making it the hottest September since records began in 1961, according to the State Meteorological Agency (Aemet).
In terms of precipitation, the islands saw an average of 4.3 litres per square metre, which is 69% of the expected amount, classifying the month as normally dry—marking the 30th driest September since 1961.
Only three weather stations—Izaña, Parador del Teide, and Roque de Los Muchachos—reported no tropical nights, while a station in Gran Canaria, El Corral de los Juncos, experienced just one.
At least 22 automatic weather stations documented minimum temperatures equal to or exceeding 20ºC throughout the month. These stations were mainly located in Fuerteventura, Lanzarote, La Graciosa, the southern half of Gran Canaria, and El Hierro.
September was characterised by several warm spells, with brief cooler intervals. Despite some drops in the average temperature, it consistently remained above the historical norm.
The first warm spell lasted from 1 to 9 September, influenced by low temperatures along the continental coast and a high-pressure ridge from Africa. Moderate trade winds were prevalent, with some strong gusts, especially when a northward shift of the Atlantic high-pressure system reduced pressure gradients near the archipelago.
Calima, a haze caused by dust, was a constant presence, particularly at higher altitudes, peaking on 4, 6, and 7 September and affecting the higher terrain of the islands.
Warnings for extreme temperatures were issued on 8 and 9 September for parts of Gran Canaria and Tenerife, with similar advisories for Lanzarote and Fuerteventura.
A brief cool period preceded a second warm spell from 12 to 15 September, driven by a substantial low-pressure system over northwest Africa that weakened pressure gradients across the Canaries. This resulted in relative low pressure and further temperature increases.
On 15 September, the region experienced its most intense warm episode, with an average temperature reaching 28.4ºC, an anomaly of 6.7ºC for that day, with persistent calima at higher altitudes.
From 17 September, the gradual eastward movement of the African ridge and the return of trade winds brought cooler air from the north, stabilising temperatures near the average.
Conditions remained largely stable until 21 September, when another warming trend began, driven by unstable southern air masses. This period, from 21 to 24 September, saw average temperatures reach a 6.6ºC anomaly on the 24th, pushing average temperatures to 27.9ºC.
Temperature decreases commenced from 25 September due to increased cloud cover, continuing through the month’s end, with anomalies around 2ºC noted in the final days, alongside a weakening frontal system from the northwest between 29 and 30 September.
