The best time to visit Turkey is April, May and September, October which as the temperature is warm and conducive to explore the ancient sites. However, Turkey is considered a year-round destination and the best time to visit depends on the places you wish to visit and the activities you want to indulge in. April and May (spring season) is the best time for outdoor activities like trekking and cycling or exploring the archaeological sites. June through September are typically hot and dry with temperatures being particularly high making it great for island hoppers and beach lovers.
From late October, the weather starts to cool off a bit. From November to March, the weather starts to get cold predominantly in interior areas of Cappadocia where the temperature drops to below 0°C. Winters can, however, be the best time to traverse the sites as they are less busy at this time of the year.
The Aegean and Mediterranean coasts of Turkey have a Mediterranean climate with mild winters and hot summers.