The back-to-school season coincides every year with one of the most interesting months from a weather perspective. September is a transitional month: days are still warm, but nights start to cool, the first autumn rains appear and the risk of DANA surges along the Mediterranean coast. What is September really like in Spain?

The end of summer: when does it really arrive?

Although astronomical summer ends on September 22-23, the meteorological summer is reluctant to leave. The first half of September maintains fully summery temperatures across most of Spain:

  • Andalusia and Murcia: highs of 32-36 °C in the first fortnight, dropping to 28-32 °C by month's end.
  • Valencia and the Balearics: 28-32 °C, with the sea still very warm (25-27 °C). Ideal for the beach until late September.
  • Madrid and the plateau: 28-33 °C in the first week, falling to 24-28 °C. Overnight lows shift from 18 °C to 12-14 °C.
  • Northern coast: 22-26 °C. September is one of the best months in the north, with less rain than October and pleasant temperatures.
  • Canary Islands: stable at 26-29 °C, with occasional Saharan haze (calima).

The first autumn rains

September marks the arrival of the first significant rainfall after the dry summer, especially in:

  • Mediterranean coast: the month with the highest risk of torrential rain from DANAs. The Mediterranean, at 25-27 °C, provides energy for explosive convective storms.
  • Galicia and the northern coast: Atlantic fronts become more frequent in the second half of the month.
  • Central System and northern plateau: late-summer thunderstorms, often with lightning and hail.

Always check weather warnings in September, especially if you live in or are travelling to the Mediterranean coast.

The "veranillo de San Miguel" — Spain's Indian summer

A recurring feature of Spain's climate is the veranillo de San Miguel, which usually occurs around September 29 (the feast of St Michael the Archangel). It is a spell of several days with above-average temperatures, clear skies and settled weather, caused by a temporary expansion of the Azores anticyclone.

It does not happen every year with the same intensity, but it is frequent enough to be enshrined in traditional sayings: "Por San Miguel, el calor vuelve otra vez" (By St Michael's Day, the heat returns again).

Tips for the back-to-school season

  • Dress in layers: cool mornings (15-18 °C inland) and still-warm middays. Children need a light jacket they can take off.
  • Sunscreen: UV radiation is still high in September, especially in the south and the Canaries.
  • Check the weekly forecast on Meteo.es: September is unpredictable and can swing from 35 °C to rain within days.
  • Pack an umbrella and boots from the second half of the month, especially on the northern coast and the Mediterranean.

September is a month of contrasts: the last beach swims, the first autumn scarves and the uncertainty of the gota fría. With the right weather information, the return to routine will be smoother.