The usual time to visit the Bulgarian Black Sea for swimming runs from early summer to early autumn, when the water passes 20 °C and lifeguards cover the main beaches. High summer brings the warmest sea and the hotels' own high season. Either side, the water is cooler and some pools and beach services are closed.
Black Sea Bulgaria weather by month: the figures
Air figures are 30-year averages (1991 to 2020) worked out from the national met office's monthly records for Varna in the north and Burgas in the south. They blend day and night, so afternoons feel warmer. Sea figures are the met office's reports for each month of 2026, since no long-term sea average is published.
| Month | Air, Varna | Air, Burgas | Sea in 2026, start to end of month | Lifeguards |
|---|---|---|---|---|
| May | 16.2 °C | 16.6 °C | 12 to 13 °C, rising to 18 to 20 °C | not yet |
| June | 21.0 °C | 21.4 °C | 19 to 20 °C, rising to 25 to 27 °C | from 1 June |
| July | 23.3 °C | 23.7 °C | 25 to 27 °C, easing to 23 to 25 °C | daily |
| August | 23.5 °C | 23.9 °C | 24 to 27 °C, briefly 28 °C near Burgas | daily |
| September | 19.1 °C | 19.7 °C | 24 to 26 °C, falling to 20 to 21 °C | to 30 September |
| October | 14.0 °C | 14.6 °C | 20 to 22 °C, falling to 15 to 18 °C (2025 report) | none |
Rain is light in high summer: over those 30 years August was the driest month at both stations and October the wettest. There are no coastal sunshine averages, but every station logged more sun than its normal in August 2026.
May: long days, cold water
May suits walking and old towns, with average air around 16 °C, but the sea lags behind. In 2026 it opened the month at 12 to 13 °C and reached 18 to 20 °C only in the last days.
On 12 and 13 May a light south-easterly wind brought cold deep water to the shore north of Varna and cut the temperature there by 4 to 5 °C. There are no lifeguards yet, though Sunny Beach turned on full resort lighting from 1 May 2026 for its first foreign guests.
June: the sea catches up
The water warms fastest in June. In 2026 it rose from 19 to 20 °C at the start to 25 to 27 °C by the end, and sunshine ran around or above normal across the country. Lifeguards work on designated beaches every day from 1 June, 09:00 to 18:30.
Varna's cultural summer starts here. In 2026 the Varna Summer theatre festival ran from 31 May to 11 June, open-air opera at the Summer Theatre opened on 16 June, and the centenary Varna Summer music festival on 27 June. Paradise Beach Residence in Sveti Vlas starts its kids club and animation on 10 June.
July and August: the warmest sea and peak season
These are the hottest months, averaging 23 to 24 °C, and August is the driest. The sea held 24 to 27 °C through August 2026 and touched 28 °C near Burgas. Upwelling still happens: on the night of 8 to 9 July a north-westerly wind dropped the water near Shabla from 22.5 to 17 °C.
Barceló Royal Beach in Sunny Beach keeps its pool bar open until 22:00 only in July and August, against 19:00 in May, June and September. In Varna, the free International Folklore Festival ran from 31 July to 3 August, and the opera season continued to 25 August.
September: warm water, a calmer coast
September keeps much of the summer's heat in the sea. In 2026 the water started the month at 24 to 26 °C and was still 20 to 21 °C at the end. Air averages drop to 19 to 20 °C, and lifeguards stay until 30 September. Sunshine can dip: Cape Kaliakra logged only 73% of its normal sunshine that month.
In Sozopol, the Apollonia Arts Festival ran more than seventy events from 27 August to 6 September 2026. Paradise Beach Residence ends its kids club on 10 September, the rooftop bar and pool at Amelia Hotel in Albena closes on 15 September, and Lighthouse Golf & Spa Hotel in Balchik serves its private beach only to mid-September.
October: last swims, Varna's autumn calendar
October is a gamble for swimming and a good month for towns. In 2025 the sea was 20 to 22 °C on the first days and, by the end, about 18 °C on the south coast and 15 to 16 °C on the north. Air averages sit near 14 °C, it is the wettest month at both stations, and lifeguard duty has ended.
Culture carries on in Varna. The centenary music festival closed on 14 October 2026 with the BBC Symphony Orchestra, and the Autumn Salon of the Arts, the CineLibri film festival and Varna Jazz Days ran from mid-October into November. A city base suits this month better than a resort strip.
November to April in brief
Winter is not beach weather: Varna averages about 9 °C in November and under 3 °C in January. The sea fell from 13 to 16 °C to 9 to 11 °C in December 2025 and was back to only 12 to 13 °C by the end of April 2026. Hotels that say they stay open, with indoor and thermal pools, are in the year-round coastal hotels guide.
Hotels that date their spring and autumn
Few hotels print their opening months. Each one below dates something on its own site, sometimes only one part of the hotel. Ask the hotel about anything not shown.
| Hotel | Resort | What its own site dates | Official category | Board | Page | Book |
|---|---|---|---|---|---|---|
| Grifid Noa | Golden Sands | season terms 30 April to 31 October; sells 4 November to 19 December | 5-star | AI | View hotel | Check availability |
| Flamingo Grand Hotel & Spa | Albena | open the whole year; thermal mineral pool daily, 09:00 to 19:00 | 5-star | AI | View hotel | Check availability |
| Grand Hotel Pomorie | Pomorie | year-round; outdoor pools seasonal; bar under the bridge 1 June to 31 August | 5-star | BB, HB | View hotel | Check availability |
| Lighthouse Golf & Spa Hotel | Balchik | indoor mineral pool all year; outdoor pool June to September; beach mid-June to mid-September | 5-star | BB, HB, AI | View hotel | Check availability |
| Barceló Royal Beach | Sunny Beach | pool bar hours for May to September only | 5-star | AI | View hotel | Check availability |
| Paradise Beach Residence | Sveti Vlas | kids club and animation 10 June to 10 September | 5-star | UAI | View hotel | Check availability |
| Amelia Hotel | Albena | rooftop bar and pool for Executive rooms, 1 June to 15 September | 5-star | UAI | View hotel | Check availability |
| Reina del Mar | Obzor | listed open dates from November to April | 5-star | UAI | View hotel | Check availability |
| Saint Thomas (Sveti Toma) Holiday Village Hotel | Sozopol | summer price bands 18 May to 30 September; indoor and outdoor pools included | 5-star | BB, HB | View hotel | Check availability |
For hotels on the sand in any month, compare the beachfront hotels, or choose a resort first with the Black Sea coast guide.
Questions
When is the sea warm enough to swim in Bulgaria?
Usually from mid-June. In 2026 the met office reported 19 to 20 °C at the start of June and 25 to 27 °C by its end, then 20 to 21 °C at the end of September. May began at 12 to 13 °C. Upwelling can still cut the temperature by several degrees for a day or two.
Which month has the warmest sea temperature in Bulgaria?
Usually August, with July close behind. Through August 2026 the sea held between 24 and 27 °C and briefly reached 28 °C near Burgas. July 2026 began at 25 to 27 °C but eased to 23 to 25 °C by the end. These are single-year readings, not long-term averages.
Are there lifeguards on Bulgarian beaches in May or October?
No, not as a rule. National regulations set lifeguard cover on designated bathing beaches every day from 1 June to 30 September, between 09:00 and 18:30. Outside those dates, swim only where the hotel or the beach operator confirms that cover is in place.
Is the south coast warmer than the north?
Slightly. Over 1991 to 2020, Burgas averaged about half a degree warmer than Varna in every month from May to October. At the end of October 2025 the sea was about 18 °C in the south against 15 to 16 °C in the north, and cold upwelling in 2026 struck north of Varna.
Are coastal hotels open in October?
Some are. A few hotels state on their own sites that they open all year, and Grifid Noa in Golden Sands sets its season terms to run until 31 October. Most large beach hotels print no closing date at all, so confirm with the hotel before you book an October stay.
