#1 in September
24.1°C
NOAA Season Curve (May–Oct):
M
19.8°
J
23.6°
J
25.7°
A
26.0°
S
24.1°
O
21.0°
N
17.8°
NOAA SATELLITE DATA (1991–2020 30-YEAR CLIMATOLOGY)
HRCroatia Sea Temperature in September
Historical 30-year sea surface temperatures across 71 coastlines in Croatia for September. Derived from NOAA 0.25° blended satellite and in-situ marine observations.
Climatology Notice: Temperatures represent the 30-year long-term historical average (1991–2020 normal), not a live single-day sensor forecast.
Bathing Climatology Gauge · Croatia (September)
NOAA OISST v2.1 (0.25° Marine Grid)
23.1°C
Pleasant & Comfortable
Mean sea surface temperature across 71 monitored coastlines
Swimmability Verdict
Effortless Prolonged Bathing
Warmest Coastline
24.1°C
Coldest Surveyed Shore
21.4°C
Swimmable Ratio (≥21°C)
100% of surveyed coasts71/71
Croatia’s primary swimming window runs from 4 Jun to 7 Oct (~124 days/year). Currently 2.2°C below the August peak of 25.2°C. High ocean specific heat capacity creates distinct thermal lag: water releases stored summer warmth gradually, making early autumn bathing warmer than late spring despite cooler evening air.
Plan Your September Trip to Croatia
Autumn shoulder-season rates are currently live across Croatia. Pair warm coastal waters with discounted stays and uncrowded beaches.
Warmest Swimming Bases in Croatia (September)
The top 3 coastlines holding highest water temperatures based on 30-year NOAA climatology.
Select Month
View 12-Month Annual Overview →Adriatic Karst Inflows & Island Archipelago Circulation
The eastern Adriatic coast features deep karst topography with submerged freshwater springs (vrulje) that discharge cold mountain runoff into select coves. However, protected channels between the Dalmatian islands (Hvar, Brač, Korčula) trap summer solar heat, yielding comfortable 24.5–25.0°C August bathing temperatures.
Oceanographic Phenomenon:Subterranean Vrulja Springs & Island Shelter
Thermal Lag Characteristic:Moderate Adriatic thermal lag: the shallow basin warms rapidly in June and cools faster in late autumn under the influence of cold northeasterly Bora winds.
Peak Bathing Average:August (24.8°C)
The September Thermal Lag Advantage
Because seawater has a high specific heat capacity, it acts as a massive thermal battery. Southern European and Mediterranean basins absorb solar energy all summer, reaching maximum heat storage by late August. In September, while air temperatures drop, the water releases heat slowly, which creates sea temperatures that are typically 3°C to 5°C warmer than in June.
CYPRUS (AYIA NAPA / PROTARAS)
27.5°C
Effortless swimming
TURKEY (ANTALYA / KAŞ)
27.3°C
Warm bathwater
GREECE (CRETE / RHODES)
25.4°C
Extended season
MALTA & GOZO
26.1°C
Crystal clear
Croatia Beaches in September
Individual coordinate lookups from NOAA 0.25° marine grid.
Showing 71 coastlines
Explore Sea Temperatures by Country
Spain(23.7°C)Italy(25.9°C)Turkey(27.3°C)France(22.4°C)Greece(25.4°C)Cyprus(27.7°C)Croatia(25.2°C)Albania(25.5°C)Montenegro(25.7°C)Malta(26.7°C)Bulgaria(25.1°C)Romania(24.7°C)Slovenia(25.4°C)Portugal(20.7°C)Poland(19°C)Sweden(18.3°C)Netherlands(18.5°C)Bosnia & Herzegovina(25.2°C)Monaco(24.6°C)Latvia(18.5°C)Estonia(18°C)Lithuania(18.8°C)Germany(18.6°C)Denmark(18°C)Norway(15.3°C)Belgium(18.7°C)Faroe Islands(10.9°C)United Kingdom(16.1°C)Ireland(15.9°C)Iceland(10.9°C)Finland(16.6°C)
