October is one of the best times to visit Spain if you are seeking warmth without the scorching summer heat. The Canary Islands (Tenerife, Lanzarote, Gran Canaria) are the most reliable option, maintaining "endless summer" temperatures around 24°C to 26°C (75°F to 79°F) and warm sea waters. On the mainland, Andalusia remains the warmest region; cities like Seville, Córdoba, and Málaga frequently see daytime highs reaching 25°C (77°F). The Costa del Sol also stays quite pleasant, often warm enough for beach sunbathing well into the month. While northern Spain (Galicia, Basque Country) begins to feel the autumn chill and rain, the Mediterranean coast and the southern plains offer a perfect escape for travelers looking to extend their summer while enjoying fewer crowds and lower accommodation prices.