After a stretch of unseasonably hot days to close out September, Portugal is in for a proper autumn reset. Forecasters at IPMA, the Portuguese Institute for Sea and Atmosphere, expect conditions to turn noticeably cooler and wetter from Monday, September 28, with rain likely to linger through much of the first week of October.
Meteorologist Ângela Lourenço says temperatures from Monday will be far lower than the previous week, though some inland areas may still nudge close to 30°C early on. Overnight values stay mild for the season: inland lows of 12–14°C, particularly in mountainous areas, and coastal lows around 17–18°C. Rain arrives from September 28, arriving in spells with breaks between showers rather than a week of solid grey.
The islands get their own outlook. The Azores are in line for above-normal rainfall across the whole archipelago — worth factoring in if you've booked a hiking or whale-watching trip there. Madeira's forecast is less certain, but the trend points toward a higher chance of rain too.
If you're travelling in Portugal over the next week, pack layers and a rain jacket rather than summer gear. Daytime conditions should stay pleasant, especially on the coast, but evenings inland and in the mountains will feel properly autumnal. The upside: crowds are thinning, prices are softening, and the light in Porto or Lisbon after a shower can be worth the wet umbrella. Anyone heading to the Azores should build some flexibility into outdoor plans and keep an eye on local forecasts, as the wetter-than-usual pattern could affect trail conditions on islands like São Miguel and Pico.
