ClimavisoSpain's types of severe-weather warning: which exist, when they trigger and where most
Published 11 October 2026 · Climaviso
AEMET, Spain's weather agency, issues warnings for 13 phenomena, from rain to avalanches. Eight of them make up nearly all the warnings most people ever get. This is when each one triggers, at what time of year, and which zone of Spain gets the most.
The 13 phenomena with warnings
AEMET's warning plan covers rain, snow, wind, storms, maximum temperatures (heat), minimum temperatures (cold), coastal hazards, suspended dust, fog, galernas, rissagues, snowmelt and avalanches.
The last four are local. Galernas, sudden north-westerly wind shifts, are only warned on the coasts of Galicia, Asturias, Cantabria and the Basque Country. Rissagues, sudden sea-level oscillations, only in the Balearics. Snowmelt, in parts of the Duero and Ebro basins where the river authorities have an agreement with AEMET. Avalanches, in the mountains.
The eight you see most
| Type | When yellow triggers | Zone-days a year | Busiest months | Zone with most, 2019–2025 |
|---|---|---|---|---|
| Rain | 15–20 mm in an hour or 40–60 mm in 12 hours, depending on the zone | 3,450 | September, June | Pirineo de Girona (345 days) |
| Heat | Highs of 34 to 38 °C, depending on the zone | 2,826 | July, August | Campiña cordobesa (357) |
| Storms | Strong storms: lots of lightning, locally heavy rain, very strong gusts or hail over 1 cm | 2,802 | June, September | Pirineo de Girona (318) |
| Wind | Gusts of 70 to 90 km/h, depending on the zone | 2,461 | January, December | Prelitoral sur de Tarragona (366) |
| Cold | Lows of −1 to −6 °C, depending on the zone | 699 | January, February | Pirineo de Lleida (159) |
| Snow | 2 or 5 cm in 24 hours, depending on the zone | 621 | January, March | Valle de Arán (213) |
| Fog | Dense, widespread and persistent fog. Yellow only | 216 | December, January | Depresión central de Lleida (87) |
| Dust | Suspended dust, usually with visibility below 3,000 m. Yellow only | 82 | January, February | Fuerteventura (60) |
Zone-days a year: 2019–2025 average across all of Spain's zones (one zone with a warning on one day is one zone-day). Thresholds: annex 1 of the Meteoalerta plan.
Where each one triggers
Rain and storms cluster in the Pyrenees and the Catalan pre-Pyrenees: Pirineo de Girona tops both lists, with Prepirineo de Barcelona and Gúdar y Maestrazgo (Teruel) next for storms. Heat rules the Guadalquivir valley: after the Córdoba countryside come the Jaén stretch of the valley (339 days) and Morena y Condado (291). Wind, in southern Tarragona and inland northern Castellón.
Fog belongs to the big inland plains in winter: the Lleida plain and the Valladolid and Zamora plateaus have almost the same number of days. And suspended dust is almost exclusively Canarian: only 13 zones had any dust warning from 2019 to 2025.
Some zones have never had certain warnings. The western Asturian coast and A Mariña (Lugo) didn't have a single heat warning from 2019 to 2025, and 107 zones had none for fog.
Several at once
Several warning types can coincide in the same zone on the same day. From 2019 to 2025 that happened on 19,884 zone-days, 28% of all of them. By far the most common pair is rain and storms (14,745 zone-days), followed by rain and wind (2,632), heat and storms (1,333) and snow and wind (939).
A few rules worth knowing
- Thresholds change from zone to zone. The yellow heat warning starts at 34 °C on the Cantabrian coast and at 38 °C in the Guadalquivir valley; the one-hour rain warning at 15 or 20 litres per square metre. More in what each colour means.
- There are no snow warnings above 1,500 metres on the mainland, 2,000 in the Canaries or 600 in the Balearics, unless agreed locally with civil protection.
- Storms have no numeric threshold per zone: yellow is for strong storms and orange for very strong ones (gusts over 90 km/h or hail over 2 cm). The rule is the same across Spain.
- Coastal warnings are for wind at sea of 50 km/h (force 7) or waves of 3 or 4 metres, depending on the coast. In the Balearics, from May to September, yellow drops to 40 km/h and 2 metres.
More guides
- How severe-weather warnings work in Spain
- Yellow, orange or red warning: what each colour means
- Spain's 182 warning zones and which one is yours
Sources
- Phenomena with warnings: AEMET, how to read warnings (Spanish).
- Thresholds and criteria: AEMET, Meteoalerta plan, annex 1: thresholds and warning levels (31 May 2022, Spanish).
- Counts: AEMET's warning archive (CAP format, AEMET OpenData), collected by Climaviso since June 2018.
Towns in this article
A warning is not damage; a zone is not a building.