Istanbul is a four-season destination where each visit is a different city. The numbers below are real — monthly weather computed from the ERA5 climate archive for Istanbul's exact coordinates — so this page answers the question most guides dodge: which months are actually worth your leave days?
The short answer: aim for July, August, October, skip December if you can, and read the packing notes before you book. Autumn color or spring bloom weeks are short — time them and the trip upgrades itself.
| Month | Day / Night | Rain | Travel score |
|---|---|---|---|
| January | 10.1° / 4.9°C | 99mm | 88 |
| February | 12.7° / 6.6°C | 26mm | 97 |
| March | 13.8° / 5.5°C | 72mm | 91 |
| April | 19.8° / 11.5°C | 62mm | 92 |
| May | 20° / 12°C | 67mm | 92 |
| June | 29.4° / 19.9°C | 23mm | 97 |
| July | 31° / 22.6°C | 20mm | 98 |
| August | 30.1° / 21.7°C | 12mm | 99 · best |
| September | 26.6° / 18.7°C | 97mm | 88 |
| October | 20.7° / 13.6°C | 14mm | 98 |
| November | 14.8° / 9.2°C | 69mm | 91 |
| December | 11.6° / 8°C | 162mm | 80 · toughest |
Pack layers you can add or shed — the daily temperature swing is real. Comfortable walking shoes beat everything else in your bag.
Give Istanbul 3–5 focused days. Mornings for the headline sights (crowds arrive after 10), afternoons for neighbourhoods, evenings for food. The free RoamWise planner turns this into a full day-by-day itinerary with budgets in your currency — and shows the crowd calendar for Istanbul next to 195+ other destinations.
🥷 Plan Istanbul free — crowd calendar, budget & AI itinerary →July, August, October score highest on our weather-comfort index — daytime around 31°C with manageable rainfall. Autumn color or spring bloom weeks are short — time them and the trip upgrades itself.
December is the toughest window (11.6°C days, ~162mm rain). Peak summer brings peak crowds and prices; late spring and early autumn are the insider windows.
Pack layers you can add or shed — the daily temperature swing is real.
Most travelers are happy with 3–5 focused days; add 2 more if you want day trips around Istanbul. The free RoamWise planner builds the day-by-day plan.