Average temperatures in October
October in Portugal brings cooler weather and the start of the rainy season, but it’s still a comfortable time to be outside. Daytime highs usually range from 64°F (18°C) to 73°F (23°C), while nights can dip to around 52°F (11°C) to 61°F (16°C). Compared to the hotter, drier summer months, October feels milder and a bit more unpredictable—sunny spells mixed with cloudy days and the occasional shower.
The Atlantic is starting to cool, but sea temperatures typically sit around 66°F (19°C) to 70°F (21°C), which some people still find fine for a swim—especially earlier in the month or in the south. Portugal sees about 11 hours of daylight in October, so there’s still time to get out and explore before it gets dark.
Porto and northern Portugal
In the north, including Porto, October tends to be cooler and wetter than other regions. Highs are usually between 64°F (18°C) and 68°F (20°C), with lows around 54°F (12°C) to 57°F (14°C). Rain becomes more frequent, so you’ll want to pack for wet weather if you’re spending time outside. Sea temperatures around Porto average 66°F (19°C), which might feel too chilly for swimming, but it’s still a good month for city walks and day trips if you're dressed for the conditions. See our guide to how many days you need in Porto.
Lisbon and central Portugal
Lisbon and central Portugal stay relatively mild in October, with daytime temperatures around 70°F (21°C) to 73°F (23°C) and nights cooling to between 57°F (14°C) and 61°F (16°C). The city stays active well into the evening and it's a great time for a Lisbon city break. Rain starts to show up more often, but there are still plenty of dry days. The sea here is around 68°F (20°C) to 70°F (21°C), so you might still get a swim in, especially at the start of the month. It’s a good time to visit if you’re after fewer crowds.
The Algarve and southern Portugal
Southern Portugal, including the Algarve, tends to hang on to the warmth a bit longer. You can expect daytime highs between 73°F (23°C) and 77°F (25°C), and nighttime temperatures between 61°F (16°C) and 64°F (18°C). There’s a slight uptick in rain, but most days are still good for being outside. The sea stays around 70°F (21°C), which is still decent for swimming if you’re used to cooler water.
Madiera
Madeira in October feels warm and humid, with more rain than in the summer but still plenty of chances to enjoy the outdoors. Daytime temperatures usually reach 73°F (23°C) to 77°F (25°C), while nights stay around 64°F (18°C) to 68°F (20°C). The sea is still comfortable at around 73°F (23°C), so swimming and boat trips are still in the picture. Rain comes in short bursts, so it’s worth packing a light waterproof layer.