Andoain is located in the northeastern part of Spain, in the heart of the Basque Country. The city lies within the province of Gipuzkoa, which is known for its rolling green hills, river valleys, and proximity to the Atlantic Ocean. Andoain is situated inland, but it is not far from the beautiful beaches of San Sebastián, which is only about 16 kilometers to the northeast. The surrounding landscape is dominated by the nearby mountains, including the famous Aizkorri-Aratz Natural Park and the Urumea River, which flows through the region.
The climate in Andoain is characterized by mild temperatures and plenty of rainfall, typical of the Atlantic coastal regions of Spain. Summers are warm but rarely hot, with average temperatures ranging between 18°C and 25°C (64°F to 77°F), making it an ideal time for visitors to enjoy outdoor activities and explore the scenic beauty of the area. Winters are cooler, with temperatures averaging between 7°C and 14°C (45°F to 57°F). The best time to visit Andoain is during the spring and summer months when the weather is pleasant, and the natural surroundings are lush and green.