ClimavisoAugust 2023 heatwave: heat across much of Spain, 20–27 August 2023
20 August 2023 to 27 August 2023. Updated 26 October 2026.
AEMET records a heatwave from 17 August to 25 August 2023.
Over 8 days, 118 of Spain's 182 warning zones had an orange or red warning for heat: 303 zone-days at orange or red, 7 of them red. The day with the most zones at orange or red was 23 August, with 66 zones.
23 August was the day with the most people in zones under an orange or red warning: 22.7 million people live there (INE municipal register, 2025).
How it compares
- It is number 8 of 119 episodes since June 2018 by zone-days at orange or red.
- Among the 37 heat episodes, it is number 6.
- There hadn't been a heat episode this widespread since July 2022.
Day by day
| Day | Red | Orange | Yellow | Orange or red warnings for |
|---|---|---|---|---|
| Sun 20 August | — | 18 | 85 | heat |
| Mon 21 August | — | 47 | 56 | heat |
| Tue 22 August | — | 61 | 64 | heat |
| Wed 23 August | 4 | 62 | 84 | heat |
| Thu 24 August | 3 | 45 | 96 | heat |
| Fri 25 August | — | 24 | 62 | heat |
| Sat 26 August | — | 15 | 57 | rain, storms, heat |
| Sun 27 August | — | 24 | 34 | rain, storms, wind |
Zones with a warning each day, at their highest level that day.
The zones
And 55 more zones with yellow warnings only.
What AEMET's stations measured
The most measured in the zones with an orange or red warning, on their warning days: a high of 44.5 °C at Montoro (Campiña cordobesa) on 21 August.
| Zone | Highest temperature |
|---|---|
| Campiña cordobesa | 44.5 °C Montoro · 21 August |
| Campiña gaditana | 44.1 °C Jerez de la Frontera Aeropuerto · 25 August |
| Interior sur de Valencia | 44.1 °C Xàtiva · 25 August |
| Norte de Burgos | 44.1 °C Miranda de Ebro · 23 August |
| Bizkaia litoral | 44.0 °C Bilbao Aeropuerto · 23 August |
| Morena y Condado | 43.9 °C Andújar · 21 August |
| Prelitoral sur de Tarragona | 43.9 °C Estación de Tortosa (roquetes) · 23 August |
| Sierra sur de Sevilla | 43.9 °C La Roda de Andalucía · 20 August |
| Campiña sevillana | 43.8 °C Écija · 21 August |
| Litoral de Huelva | 43.8 °C Almonte · 22 August |
| Vegas del Guadiana | 43.6 °C Badajoz · 21 August |
| Andévalo y Condado | 43.5 °C Villarrasa · 25 August |
| Centro y valle de Villaverde | 43.3 °C Ramales de la Victoria · 23 August |
| Ribera del Ebro de La Rioja | 43.3 °C Logroño, Aeropuerto · 24 August |
| Sierra norte de Sevilla | 43.3 °C La Puebla de los Infantes · 21 August |
| Bizkaia interior | 43.2 °C Orozko, Ibarra · 23 August |
| Liébana | 43.2 °C Cillorigo de Liébana, Tama · 23 August |
| Sierra y Pedroches | 43.1 °C Espiel · 21 August |
| Vega del Segura | 43.0 °C Archena · 25 August |
| Pirineo de Lleida | 42.9 °C Llimiana · 23 August |
And 96 more zones with an orange or red warning.
For each zone, the highest value its AEMET stations measured on the episode's warning days (the lowest, for the low temperature), with the station and the day. Rain from 07:00 to 07:00 UTC; gust: the day's strongest. It is what the zone's stations measured, not every town, and a measurement, like a warning, is not damage.
How AEMET's warnings unfolded
The red warning reached 7 zone-days. AEMET issued it ahead of time in 6 of them (median: 26 h) and for the current hour in the other 1: warnings are also raised as things unfold. The first warning of any level for those same days had come a median 36 h earlier.
| Zone | Day | First warning | Red issued | For · notice |
|---|---|---|---|---|
| Bizkaia interior | Wed 23 | Sun 20 Aug, 23:50 orange | Mon 21 Aug, 23:01 | 13:00 · 38 h before |
| Cuenca del Nervión | Wed 23 | Sun 20 Aug, 23:50 orange | Tue 22 Aug, 11:18 | 13:00 · 26 h before |
| Gipuzkoa interior | Wed 23 | Sun 20 Aug, 23:50 orange | Tue 22 Aug, 11:18 | 13:00 · 26 h before |
| Ampurdán | Wed 23 | Sun 20 Aug, 23:50 orange | 15:33 | 15:00 · for the current hour |
| Ribera del Ebro de Zaragoza | Thu 24 | Mon 21 Aug, 23:50 orange | Wed 23 Aug, 11:21 | 13:00 · 26 h before |
| Ribera del Ebro de La Rioja | Thu 24 | Mon 21 Aug, 23:50 orange | Wed 23 Aug, 11:23 | 13:00 · 26 h before |
| Ribera del Ebro de Navarra | Thu 24 | Mon 21 Aug, 23:50 orange | 09:50 | 13:00 · 3 h before |
The full timeline: 401 changes at orange or red
Only the changes involving red are listed: there were 401 in all.
Mon 21 August
- Bizkaia interior: Raises the heat warning to red: Wednesday 23, 13:00–21:00. Highs of 42 °C.
Tue 22 August
- Cuenca del Nervión: Raises the heat warning to red: Wednesday 23, 13:00–21:00. Highs of 42 °C.
- Gipuzkoa interior: Raises the heat warning to red: Wednesday 23, 13:00–21:00. Highs of 41 °C.
Wed 23 August
- Ribera del Ebro de Zaragoza: Raises the heat warning to red: Thursday 24, 13:00–21:00. Highs of 42 °C.
- Ribera del Ebro de La Rioja: Raises the heat warning to red: Thursday 24, 13:00–21:00. Highs of 42 °C.
- Ampurdán: Raises the heat warning to red: Wednesday 23, 16:00–19:00. Highs of 40 °C.
Thu 24 August
- Ribera del Ebro de Navarra: Raises the heat warning to red: Thursday 24, 13:00–21:00. Highs of 42 °C.
AEMET's issue times, in mainland Spain time (Canary Islands in island time). Notice is the time from issue to the first hour the warning covered; a warning issued “for the current hour” runs from the hour it is published.
What this says and what it doesn't
A warning is an AEMET forecast, not a measurement or a damage report: it says a threshold is expected to be exceeded in a zone. A warning is not damage; a zone is not a building.
A zone-day is one warning zone with a warning on one day. Ten zones at orange on the same day make ten zone-days. A day with several warnings in one zone counts once, at its highest level.
Each zone has its own thresholds, so an orange heat warning in Asturias doesn't mean the same temperature as in Córdoba. More in how warnings work.
To cite: “Climaviso, from AEMET warnings”.
Source: official AEMET warnings, collected by Climaviso since June 2018.
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