Three instruments, three bodies
In the Canaries the word warning covers three separate procedures. The aviso por riesgo para la salud comes from the Dirección General de Salud Pública of the SCS, belongs to the Plan de vigilancia y prevención frente al calor de Canarias and is triggered when the maximum-temperature thresholds are exceeded in a MeteoSalud zone — on data from AEMET and the health ministry, the department says. AEMET's own aviso is purely meteorological, under the Meteoalerta plan. The alerta of the Dirección General de Emergencias is civil protection, under the PEFMA plan. On 12 September only the first is active.
Which zones are covered — and which are not
The release names zones, not islands. Level 2 applies on Gran Canaria to the zones of Las Palmas de Gran Canaria and Telde, on Tenerife to Santa Cruz de Tenerife–El Rosario, and on Lanzarote to the zone of Lanzarote, which covers the whole island; level 1 applies to the zone of Fuerteventura, likewise the whole island. The north, the summits, the south and the west of the two large islands are not covered — not even where the forecast shows higher figures than in the capital. The department gives no end date.
What orange means, according to the health department
By its definition, level 2 denotes a "moderate risk in the vulnerable population" — people over 65 or with risk factors associated with the effects of heat — and in the general population where sun exposure is prolonged; for people over 65 with additional risk factors it states an "elevated risk". Level 1 denotes a "mild risk in the vulnerable population". Its recommendations: reschedule outdoor activities that involve physical effort, stay in cool places as long as possible, take protective measures at cultural and religious events and watch for heat symptoms among those attending.
What AEMET is actually forecasting
AEMET said on 12 September that from Sunday temperatures in many zones would be "between 5 and 10 °C above those normal for these dates". The rise is unevenly spread. In the municipal forecast issued at 07:11 on 12 September, Sunday reaches at most 34 degrees anywhere in the archipelago; in the warned zones it stays below that — Santa Cruz de Tenerife and Arrecife 32 each, Telde 31, Las Palmas de Gran Canaria and El Rosario 28 each. The peak comes later: on Tuesday 37 degrees in Arrecife and Tías, 39 in San Bartolomé on Lanzarote. For Monday the health department expects calima in the midlands and on the eastern islands; it lowers humidity and alters the perception of the real temperature. No thunderstorms are forecast.
Wildfire level, civil protection — and the summer before it
The wildfire level did not rise with the health warning; it fell shortly before it. The Dirección General de Emergencias ended the alerta for El Hierro, La Palma, Tenerife, La Gomera and Gran Canaria at 07:00 on 11 September, because temperature, humidity, wind and the state of the fuels no longer supported it. The five islands remain in the prealerta in force for the season since 1 June. For context: the MoMo system of the Instituto de Salud Carlos III estimated 89 heat-attributable deaths in the Canaries from 15 May to 31 August, against 129 in the same period of 2025 — a statistical estimate, not a count of certified causes of death.