The September shift is underway. Summer crowds have disappeared. Changing wind patterns are bringing cool gusts from the north. While daylight, which recently seemed endless, is starting to creep away earlier and earlier. You hate to admit it, but autumn has arrived.

These early fall weeks—with their still-warm days and chilly nights—are your final chance to escape to Estonia’s islands this year. Sure, you could visit during the winter. But frigid temperatures, strong gusts, and widespread closures are just a few of the deterrents. Now is the time to visit Saaremaa.

Saaremaa is Estonia’s largest island. It sits off the country’s west coast in the Baltic Sea. It’s famous for its meteorite craters, steep cliffs, and windswept beaches. Little villages are surrounded by old stone fences. Houses still have thatched roofs. Windmills look like they were stolen from the Netherlands. Plus its picturesque capital was built around a medieval fortress.

If it weren’t for Kuressaare Castle, Kuressaare could pass for a New England beach town. A ferry from Virtsu, on the mainland, connects to Saaremaa in less than 30 minutes. Beaches on the outskirts of town have long boardwalks, soft white sand, and sunbathers who know that their time is limited. The harbor is lined with sailboats that will soon be taken out of the water for the winter. Churches have twin steeples, wooden pew boxes, and wrought-iron gates. Town Hall is guarded by a pair of stone lions. While every hotel has some sort of spa.

Kuressaare Castle is never far from sight, though. The fortress sits on an artificial island, surrounded by a moat, overlooking the Gulf of Riga. Its original wooden fortifications were built as the residence of local Catholic bishops in the 14th century. They were greatly expanded—with stones and turrets—after the Danish seized control of the island in the 16th century. It’s now home to a museum with exhibits about the island’s history and natural beauty; most people come to see the dungeon where prisoners were devoured by real lions. It’s also considered one of the best-preserved castles in the Baltics.

After a day exploring the beaches, the town, and the castle, you’re ready to check out the spas that everyone keeps mentioning. It turns out that the place at which you’re staying, the Georg Ots Spa Hotel, is the perfect place to do so. The minimal hotel, named after a famous Estonian opera singer, sits along Kuressaare’s waterfront. Your room, filled with pale wood furniture, even overlooks the castle. So do the huge windows and the open-air terrace in the restaurant. Once you see its menu—green mussels with a breadcrumb crust, fried pike perch in a lobster-butter sauce, and warm rhubarb crumble—you quickly decide to eat in tonight.

Staying in gives you a chance to hear about the multiple saunas and pools, each set at a different temperature, in the spa. You can move between contrasting warm and cold pools, a traditional Finnish sauna, and a nude Sven sauna. It sounds like the perfect way to begin the day, since it takes a while for the temperature to warm up anyway, tomorrow. You’re easing your way into the flow of fall.