Istanbul vs Varna: which is sunnier?
🇹🇷 Türkiye vs 🇧🇬 Bulgaria · 230 km apart · long-term climate normals (NASA POWER, 2001–2020)
Istanbul and Varna are virtually tied for annual sunshine — about 2,201 vs 2,248 hours a year. Varna has the higher Sunshine Score in 4 of 12 months, Istanbul in 3 (5 within 2 points).
Scores are the 0–100 Sunshine Score — sunshine, daytime warmth and dryness in one number, per month.
At a glance
| Istanbul | Varna | |
|---|---|---|
| Sunshine hours / year | 2,201 | 2,248 |
| Sunniest month | July (87/100) | August (86/100) |
| Nov–Feb average score | 13/100 | 9/100 |
| Jun–Aug average score | 86/100 | 84/100 |
| Rain / year | 719 mm | 538 mm |
| Warmest sea | 27°C / 81°F | 27°C / 81°F |
| Peak midday UV | 8 (very high) | 7 (high) |
Istanbul vs Varna month by month
| Month | Sunshine Score | Day high °C | Rain mm | Sea °C | ||||
|---|---|---|---|---|---|---|---|---|
| Istanbul | Varna | Istanbul | Varna | Istanbul | Varna | Istanbul | Varna | |
| January | 0 | 0 | 8° | 6° | 94 | 53 | 10° | 9° |
| February | 0 | 0 | 8° | 7° | 75 | 38 | 9° | 8° |
| March | 7 | 7 | 9° | 9° | 60 | 41 | 9° | 9° |
| April | 28 | 36 | 12° | 13° | 43 | 30 | 13° | 13° |
| May | 64 | 77 | 17° | 19° | 31 | 43 | 16° | 16° |
| June | 85 | 83 | 22° | 24° | 35 | 50 | 23° | 23° |
| July | 87 | 84 | 25° | 27° | 26 | 46 | 27° | 27° |
| August | 87 | 86 | 25° | 27° | 23 | 30 | 27° | 27° |
| September | 80 | 83 | 23° | 23° | 62 | 50 | 25° | 24° |
| October | 63 | 67 | 18° | 18° | 87 | 60 | 20° | 20° |
| November | 39 | 35 | 14° | 13° | 77 | 43 | 16° | 15° |
| December | 12 | 0 | 10° | 8° | 106 | 54 | 13° | 11° |
The sunnier month by month: Jan even · Feb even · Mar even · Apr Varna · May Varna · Jun even · Jul Istanbul · Aug even · Sep Varna · Oct Varna · Nov Istanbul · Dec Istanbul.
When to pick which
- November–February: Istanbul (average score 13/100 vs 9). Daytime highs are similar (10°C vs 9°C). See the winter sun ranking.
- March–May: Varna (average score 40/100 vs 33). Daytime highs are similar (13°C vs 14°C).
- June–August: too close to call — Istanbul averages 86/100, Varna 84/100. Varna is the warmer, around 26°C daytime highs vs 24°C.
- September–October: Varna (average score 75/100 vs 72). Daytime highs are similar (21°C vs 21°C).
Sea temperature
Both seas peak at 27°C / 81°F. Swimmable water (21°C+): Istanbul about 4 months a year, Varna about 4 months a year. Month-by-month sea temperatures are in the table above.
Full month-by-month guides: Istanbul weather by month · Varna weather by month · Best time to visit Türkiye.
More comparisons: Istanbul vs Burgas · Istanbul vs Mytilene · Varna vs Bucharest · Varna vs Burgas · all head-to-heads