How severe-weather warnings work in Spain

Published 11 October 2026 · Climaviso

A severe-weather warning is a forecast: AEMET, Spain's weather agency, announces that a threshold for rain, wind, heat or another phenomenon is expected to be exceeded in a zone. This guide explains who issues them, how far ahead and when, what a warning says, and what it doesn't.

Who issues them

Severe-weather warnings are issued by AEMET, Spain's State Meteorological Agency, under the Meteoalerta plan, the national plan for forecasting and monitoring adverse weather. The current version of the plan was approved in 2022, and its thresholds annex is dated 31 May that year.

The plan sets three things: which phenomena get warnings (13, from rain to avalanches), the zones warnings are issued for (182 across Spain), and each zone's thresholds for each level: yellow, orange and red.

What a warning says

Each warning gives the phenomenon, the level, the zone, when it starts and ends, the most likely value and the probability, and may carry a comment. A real example, from 29 October 2024 in inland northern Valencia: red rain warning, 90 mm in an hour and 180 mm in 12 hours, from 07:00 to 11:59.

AEMET also publishes special warnings when an episode is intense, long or combines several phenomena: heat waves, cold waves or tropical storms, for example.

How far ahead, and at what time

Warnings are issued up to 72 hours ahead. AEMET has preferred issue windows (mainland Spanish time):

Time	What is issued
07:30–09:00	Warnings for today
10:30–11:30	Warnings for tomorrow and the day after
17:00–19:00	Review of all warnings
23:50	Early notice for three days ahead

Outside those windows, a warning can be issued, updated or cancelled at any time if the forecast changes significantly. On the day of Valencia's DANA, for example, the red warning came at 07:31 and was renewed and extended several times during the day: the full sequence, hour by hour.

Different thresholds in each zone

A warning triggers when a zone's threshold is expected to be exceeded, and thresholds are set by what is rare there. The yellow heat warning starts at 34 °C in Bizkaia and at 38 °C in the Córdoba countryside; red, at 40 and 44. Wind, at gusts of 70, 80 or 90 km/h depending on the zone. More examples in what each colour means and the types of warning.

Those thresholds barely change. According to an analysis by the fact-checker Maldita, maximum-temperature thresholds have changed in only 10 of the 182 zones since 2006, always upwards. That's why warnings from different years can be compared: we do it every day in the warnings review.

What a warning is not

Not a measurement. It's a forecast. It may rain less than warned, or more.
Not damage. AEMET separates how dangerous a phenomenon is from risk, which also depends on who and what is exposed, and how vulnerable they are.
Not an exact spot. It's issued for a whole zone, which can cover dozens of towns. See the 182 warning zones.
Not an emergency alert. What is done with a warning (activating an emergency plan, closing schools, sending an ES-Alert to phones) is decided by the civil protection authorities. On 29 October 2024, the ES-Alert reached phones in Valencia at 20:11, more than twelve hours after the first red warning.

Warnings as open data

AEMET publishes warnings in CAP (Common Alerting Protocol), an international standard, through AEMET OpenData. Climaviso has kept that archive since June 2018 and turns it into histories by town and by zone: how many warning days there were, of which colour and why.

More guides

Sources

What warnings contain, issue times and special warnings: AEMET, how to read warnings (Spanish).
Thresholds: AEMET, Meteoalerta plan, annex 1 (31 May 2022, Spanish).
Threshold changes and plan version: Maldita, 5 September 2024 (Spanish).
Time of the ES-Alert on 29 October 2024: Maldita, 30 October 2024 (Spanish).
Warnings: 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.