Maximum temperature, NWS heat index, humidex and 7-day forecast for Santiago de Compostela and the rest of Galicia. AEMET regional record: 43.8 °C (Ourense, July 2022).
| Day | T max | Feels-like max | Over threshold |
|---|---|---|---|
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Real-time Open-Meteo data.
Galicia is one of the Spanish regions where summer heat reaches critical levels during June, July and August. The official AEMET record for the region is 43.8 °C (Ourense, July 2022). The number of days above 35 °C has increased measurably over the past two decades, partly due to global warming and partly to the urban heat island effect in major cities.
The feels-like temperature, computed with the NWS Heat Index or the Canadian Humidex, typically exceeds the dry-bulb value by 3-8 degrees when humidity rises above 50%. In coastal areas this is the norm; inland, the most dangerous factor is persistent tropical nights (above 20 °C) that prevent physiological recovery.
People over 65, those with chronic cardiac or respiratory conditions, pregnant women and small children are the most vulnerable groups. Use municipal cooling centres (libraries, community centres, air-conditioned shopping malls) during the central hours of the day. Stay hydrated and watch for headaches, nausea and absent sweating. Dial 112 for any suspected heat stroke anywhere in Galicia.
The 7-day forecast box shows expected highs and maximum feels-like temperatures for Santiago de Compostela. A run of more than 5 days with feels-like values above 35 °C is flagged as a probable heatwave, based on our simplified version of the AEMET rule (3 days above the 95th percentile of historical summer highs). The map shows current-day highs for Galicia. Check official AEMET warnings at aemet.es.
Galician heat is short and comes from the east. With the Atlantic depressions pushed aside and a southerly or southeasterly flow, the air crosses the plateau, drops towards the valleys of the Miño and the Sil and quickly warms the interior of Ourense, which routinely records higher maxima than much of Andalusia. On the coast, the rías and the humid north damp all of it down.
35 °C does not mean the same thing in Córdoba as in Santander, so a fixed number is the wrong place to start. Taking Santiago de Compostela as the reference point, the extreme-heat threshold specific to this place — the 95th percentile of July and August maxima, which is the criterion AEMET uses — sits at 30.6 °C, in the middle of the national range. It is exceeded on about 4 days a year.
In absolute terms that is 0 days a year at 35 °C or above and 0.0 at 40 °C or above, with a mean August maximum of 23.9 °C. The nights count as much as the days: there are 0 nights a year when the temperature does not drop below 20 °C, though 25 is virtually never held.
That is the question that matters most, and the series answers it on its own. In Santiago de Compostela, days above that 30.6 °C threshold went from 3.8 a year on average in 1995-2004 to 5.2 in 2015-2024. The gap is small but clearly upward. Nights that do not drop below 20 °C have made the same journey: from 0 to 0 a year.
There is no universal number: 35 °C is an anomaly in Santander and an ordinary July afternoon in Córdoba. So the definition is built from each place’s own record. Applying AEMET’s criterion — three consecutive days above the 95th percentile of July and August maxima — that threshold in Santiago de Compostela stands at 30.6 °C, and across 30 years of record 13 episodes have occurred. The longest ran 5 days in a row. The hottest day in the whole series was 14 July 2022, at 36.7 °C.
The bulk falls in July, but the spread says more than the total: where the season stretches into May and September, the problem stops being occasional.
| Days ≥ 35 °C | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Of the 17 regions with a page on this site, Galicia has the 14th-highest extreme-heat threshold (30.6 °C) and ranks 4th for days a year above it. For tropical nights it ranks 16th. For scale: the highest in the country is Seville at 40.0 °C, and the lowest Santa Cruz de Tenerife at 25.2 °C.
On how fast it is worsening it ranks 17th of 17. That is the figure worth watching rather than the threshold itself: the starting point depends on each place’s climate, but the increase can be compared across all of them.
From ERA5-Land, the reanalysis produced by the European Centre for Medium-Range Weather Forecasts, downloaded from the Copernicus Climate Data Store under a CC-BY licence: hourly temperature between 1995-01-01 and 2024-12-06, 30 complete years, taken at the 42.90°, -8.50° cell, the closest to Santiago de Compostela. ERA5-Land runs on a grid of about 9 km and covers land only, which keeps the sea from cooling the figure in coastal cities.
One caveat that changes how all of this should be read: a reanalysis is not a weather station. It smooths the terrain and cannot see a city’s heat island, so its absolute extremes fall short of what AEMET measures at a specific observatory: here the highest value in the series is 36.7 °C. That is why the figure that governs this page is not a fixed threshold but the one specific to this place, and why the real value lies not in the record but in the comparison between decades: the series is long, homogeneous and without gaps, and there a reanalysis beats any station that has changed site or instrument along the way.
