The short answer
Late April to early June, and mid-September to October, are the sweet spot: warm enough to swim, without the peak-summer heat or the peak-summer crowds and prices. If swimming isn't the priority, spring and autumn also give you far more comfortable conditions for sightseeing in the old town and visiting the ancient sites, where there's little shade.
Season by season
Spring (April–May)
Wildflowers, green hillsides, and sea temperatures that start out cool but are swimmable by May for most people. This is also when Antalya's countryside looks its best — if a day trip to Termessos or the Köprülü Canyon is on your list, this is a strong window.
Summer (June–August)
Hot and dry, regularly into the mid-to-high 30s°C (90s°F) in July and August, with the sea at its warmest. This is peak season: book accommodation and flights well ahead, and expect the busiest beaches and attractions. If you're heat-sensitive, plan outdoor sightseeing (ruins, the old town) for early morning.
Autumn (September–October)
Many regulars rate this the best window overall: sea still warm from summer, air temperatures easing, and noticeably fewer crowds after early September. Late October can bring the first rain showers.
Winter (November–March)
Mild by northern European standards (rarely below 10°C/50°F in the day) but wetter, and too cool to swim comfortably for most visitors. This is when Antalya is at its cheapest and quietest — a legitimate option if you want the old town, museums and ruins without crowds or heat, and don't mind skipping the beach.
Choosing by what you care about
| Priority | Best months |
|---|---|
| Swimming & beach time | June–September |
| Value for money | November–March (excl. NYE), or shoulder months |
| Comfortable sightseeing / walking | April–May, October |
| Fewer crowds at major sites | Late September–October, or Nov–March |
| Family trip during school holidays | Late June–August (book early) |
Worth timing around
The Aspendos International Opera & Ballet Festival runs through the summer in the ancient Roman theatre at Aspendos — a genuinely special way to see the site if the dates line up with your trip. Ramadan and the two Islamic holiday periods (Eid al-Fitr and Eid al-Adha) shift each year and can mean shorter hours at some sites; they rarely affect tourist areas much, but it's worth a quick date check before you book.