New heat peak to start the week and at the gates of autumn

Maximums will climb locally up to 35 ºC in the interior this Monday

2 min
The Pedraforca, with a serene sky, from the Lluçanès
21/09/2026 - 07:29 h

BarcelonaWith two days left until the official arrival of astronomical autumn, we still have to talk about temperatures more typical of summer than of these dates. Minimum temperatures have recorded the typical drop in recent days due to the shortening of daily daylight hours, with a significantly cooler environment at night and in the early morning, especially inland and in the Pyrenees. Maximum temperatures, on the other hand, continue to rise. Yesterday they climbed back above 33 ºC in the interior of the Ebro and in the Priorat. And this Monday there will be a heat peak, with many maximums of 30 to 35 ºC throughout the country. Although the mercury will fall back a little on Tuesday, temperatures will remain above average throughout the week, along with anticyclonic calm.

Weather forecast for Monday 21 in the morning.

Monday: rise in heat

A pleasant day across the country, with radiant sun overall and only some local morning fog or mist in some inland plains or valleys. The sun will shine brightly and only some low coastal clouds will appear, which will eventually dissipate. Pay attention to the temperatures, as there will be a heat peak that will be especially noticeable in parts of the pre-coastal area. Many maximum temperatures of 30 to 35ºC are expected quite generally, without ruling out some slightly higher values in the southern interior of the country. In short, a very warm and summery Monday is expected, with values clearly higher than usual for this time of year, which will contrast with the morning coolness.

Light westerly winds will prevail inland and weak sea breezes along the coast, while on the northern slope of the Pyrenees, light northerly winds will blow, bringing some cloudiness. The tramontane wind has been noticeable since early morning in the north of Alt Empordà and is blowing as a foehn wind, which has made the night quite warm in this sector. Throughout the day, this northern wind will gradually fade. There will be rough seas north of Cap de Begur, and along the rest of the coast, the sea will remain calm. In the Terres de l'Ebre, the light mistral wind will blow until midday.

Weather forecast for Monday the 21st in the afternoon.

Start of autumn with heat

Throughout the week we will continue to talk about an anticyclone, and this will mean that the sun will dominate without exceptions, with no prospect of rain in the medium term. The only phenomenon to highlight will be the morning fog in inland plains and valleys. No episode of rain or strong storms is expected in sight.

All this with temperatures that will drop again starting Tuesday, but always with heat at midday and values above average. There will be a marked thermal contrast between the morning coolness and the midday heat, especially due to the fact that the days are getting shorter. Therefore, we will have to dress in layers in most regions. Therefore, astronomical autumn will officially arrive on Wednesday with an atmosphere that is more summery than autumnal. On Friday, thermometers will experience another heat peak.

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