Istanbul, Türkiye:  October is a beautiful and comfortable autumn transition month in Istanbul, featuring pleasant daytime temperatures that average around 19°C to 21°C (66°F to 70°F). While early October still holds onto the warmth of late summer, evenings become distinctly chilly—dipping to around 12°C to 14°C (54°F to 57°F)—especially with the brisk breezes blowing off the Bosphorus. 

Warsaw, Poland:  October in Warsaw brings a brisk transition into true autumn, highlighting the stunning "Golden Polish Autumn" foliage alongside a sharp drop in temperature. Daytime highs typically range from 9°C to 13°C (48°F to 55°F), while crisp nights dip to 4°C to 5°C (39°F to 41°F), bringing occasional overnight frost by the end of the month. To stay comfortable, visitors should pack a warm autumn coat, thick layers, a scarf, and water-resistant walking shoes.

In both cities it is recommended to pack in versatile layers: a mix of short and long-sleeve tops, warm sweaters, and water-resistant walking shoes. Bring a light jacket or windbreaker for Istanbul’s breezy coastlines, but pack a heavier autumn coat, scarf, and hat for Warsaw’s colder nights. 

Be sure to include a modest outfit with a lightweight headscarf (for women) to meet the dress code for Istanbul's historic mosques.

As with all 20-20 trips, a dedicated security team is provided for your safety.  A security official will also be assigned to accompany the spouse/guest program.

Be careful when leaving the hotel with valuable belongings (camera, phone, jewelry, etc.) or leave these items secured in your room’s safe.

We also encourage you to stay with the group while participating in activities outside the hotel.

Please refer to the attached medical notes prepared by Dr. Karen Casper:

• Dr. Karen Casper's Medical Notes (updated Aug. 6, 2026)