A weekend with two faces: from the peak of Indian summer to a new change in weather
Temperatures will peak on Saturday, but will drop again clearly from Sunday onwards, with some showers.

BarcelonaFriday's calm, warmer weather will continue on Saturday, where temperatures will peak. A peak of warmth will make short sleeves essential in the middle of the day in many regions. The Indian summer of Sant Miquel arrived a few days late, but it's finally here, with temperatures clearly above average and highs around 30°C in the warmest areas. In fact, this Friday already saw temperatures reach 30°C locally on the Ebro River, such as in Benissanet (Ribera d'Ebre). However, this warmth will be short-lived, as a weak cold front will pass through on Sunday, reactivating some instability and significantly lowering temperatures, which will return to normal.
Saturday: very warm atmosphere
Temperatures will rise further, both minimum and especially maximum temperatures. A very hot day is expected, more typical of late summer than early October. Many temperatures will range between 23 and 28°C, but towards the west, on the Ebro River, and in some areas of the pre-coastal region, temperatures may reach or slightly exceed 30°C.
Calm weather with sunshine, occasionally blurred by the passage of some high and medium-level cloud bands, and there will also be morning fog. In the morning, there will also be some low clouds on the central coast and pre-coastal region. Between the afternoon and evening, the storm clouds will strengthen in the Pyrenees and bring some initial showers, more likely on the north face.
Sunday: change of weather
The passage of a moderately active cold front will bring about some changes. Between nighttime and early Sunday morning, scattered showers or rain will fall, especially in parts of the northern half. During the morning, scattered showers will continue to fall in the Girona region and on the Barcelona coast and pre-coast, where clouds will be fairly present throughout the day. In the afternoon, there will be repeated local and mild showers in the northeast.
However, the sun will dominate southwards and inland, especially in the west. A change in the weather will bring in mistral winds in the south and tramontana winds in the Empordà region. All of this will significantly lower temperatures, with a markedly cooler atmosphere after Saturday's peak of warmth.

Few changes in the medium term
We'll start next week cooler, both day and night, with temperatures even slightly below average. Lows will be cold in the Pyrenees, and temperatures will also drop below 10°C in many inland areas. Calm weather will prevail, and starting Tuesday, temperatures will recover, but remain around average.
The maps indicate that instability could increase on Friday and next weekend, with an increased risk of precipitation. This information is still uncertain, but we'll need to confirm it.