Side-Turkey.

Green Canyon is one of those places that quietly steals the show. Tucked into the Taurus mountains a short drive inland from Manavgat, it is not a sea coast at all but a deep, emerald-green freshwater lake — the reservoir of the Oymapinar Dam on the Manavgat River. The water sits still and cool between steep pine-covered slopes, and a slow boat across it feels worlds away from the busy beach resorts. If you are planning the trip, the question almost everyone asks first is simple: which months actually give you the best weather on the water? Here is an honest, season-by-season answer.

What Green Canyon really is (and why weather matters here)

First, a useful distinction that trips up a lot of visitors. Green Canyon (Yesil Kanyon) is the calm lake behind the Oymapinar Dam, a tall concrete arch dam on the Manavgat River that was completed in 1984. Boat tours glide across its sheltered, mirror-flat water. This is a different place from Koprulu Canyon National Park, which sits on the separate Kopru River and is known for white-water rafting. So a Green Canyon trip is gentle and scenic, not an adrenaline ride — good news for families.

Because the lake is hemmed in by mountains and fed by cool spring water, it behaves differently from the open Mediterranean. The surrounding region has a classic Mediterranean climate: hot, dry summers and mild, wetter winters. That mix is exactly why the timing of your visit changes the experience so much.

The best months, season by season

Late spring: May and June

For many people this is the sweet spot. The days are warm and reliably sunny, the mountainsides are still lush and green, and the heat has not yet turned fierce. The lake water stays notably cool because it is spring-fed, so a swim is refreshing rather than bath-warm. Crowds are lighter than in high summer, which makes the boat feel calmer and the scenery easier to enjoy.

High summer: July and August

These are the hottest, busiest months, with inland daytime temperatures around the Manavgat area often reaching the low-to-mid 30s Celsius and sometimes higher. The upside on the lake is that you are surrounded by water and shade from the deck, and the cool reservoir is wonderfully welcome in the heat. The trade-off is stronger sun and more visitors. If you travel in summer, bring proper sun protection, drink plenty of water, and an early pick-up helps you enjoy the cooler part of the day.

Early autumn: September and October

Arguably the finest window of all. The fierce summer heat eases, the light turns golden, and the water is still pleasant after a long warm season. September in particular keeps summer warmth with a softer edge; by October afternoons are comfortable and evenings cooler. Fewer crowds and gentler temperatures make this a favourite for relaxed, photo-friendly days.

Winter: November to March

Winters here are mild rather than cold, but they are the wettest part of the year, and the lake is at its quietest. Some days are clear and beautiful; others bring rain. Swimming is generally too chilly for most. If your priority is dramatic green scenery and solitude over swimming, a bright winter day can still be lovely — just check the forecast and confirm running times before you set out.

Quick Facts

• Duration: Full day — exact times confirmed at booking.
• Pick-up: Hotel pick-up from Side, Manavgat & nearby resorts; time confirmed at booking.
• Includes: Round-trip hotel transfer and the lake boat cruise; lunch and on-board stops are commonly part of the day (confirmed at booking).
• Excludes: Personal spending, optional extras and any items not listed at booking.
• Family Friendly: Yes — calm lake water, no rapids, suitable for most ages.
• Best Season: Late spring (May–June) and early autumn (September–October) for the most comfortable weather; summer for warmth and swimming.
• Difficulty: Easy and relaxed — a gentle scenic cruise.

Related Excursions

• Tours & day trips from Side
• Things to do in Antalya
• Excursions from Alanya
• Day trips from Belek
• Tours from Kemer
• More travel guides on our blog

Frequently Asked Questions

Is Green Canyon the same as Koprulu Canyon?

No. Green Canyon is the calm lake behind the Oymapinar Dam on the Manavgat River. Koprulu Canyon is a separate national park on the Kopru River, famous for rafting. A Green Canyon boat trip is a peaceful lake cruise, not a rafting adventure.

When is the best time of year to go?

Late spring (May–June) and early autumn (September–October) usually offer the most comfortable mix of warm, sunny weather and lighter crowds. High summer is hottest and busiest; winter is mild but wetter and quieter.

Can you swim in the lake?

Boat trips commonly include time to swim where conditions allow. The water is spring-fed and stays cool, which feels lovely in summer heat but can be too cold for comfort in the cooler months.

Is it suitable for children and older travellers?

Yes. The lake is calm with no rapids, so the cruise is gentle and family-friendly. As always, follow the crew's safety guidance on board.

How hot does it get in summer?

Inland around Manavgat, summer daytime temperatures often reach the low-to-mid 30s Celsius and can climb higher. Bring sun protection and water; the cool lake is a welcome relief.

What should I bring?

Sun cream, a hat, sunglasses, a swimsuit and a towel in the warm season, plus a light layer for cooler months. Comfortable footwear and a camera are always worth packing.

Do prices change by season?

Travelling outside the busiest summer weeks can offer better value, and booking direct with us removes agency and OTA commissions. We offer a best-price guarantee — just ask.

Ready to glide across the emerald water? Book your Green Canyon boat trip direct with the Murat Atalay team — message us on WhatsApp or email info@side-turkey.com. Booking direct means no middleman, our best-price guarantee, and honest local advice on the best day to go.