Turkey / Kocaeli
Altınköy Plajı
Altınköy Plajı is a 176 m-long sandy beach facing north, 1.2 km north-east of Karamürsel (Kocaeli, Turkey). The sea averages 24.0 °C in August, its warmest month, and 8.0 °C in February; it is 21 °C or warmer in July–September.
Average sea surface temperature by month. Current month outlined.
Month by month
October at Altınköy Plajı
Beach-day index 5.4/10 · Turkey median 6.2
| Measure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea °C | 8.9 °C | 8.0 °C | 8.7 °C | 11.2 °C | 15.8 °C | 20.7 °C | 23.2 °C | 24.0 °C | 22.3 °C | 19.0 °C | 15.0 °C | 11.5 °C |
| High °C | 8° | 10° | 13° | 17° | 22° | 26° | 29° | 29° | 25° | 20° | 15° | 10° |
| Low °C | 0° | 1° | 3° | 6° | 11° | 15° | 18° | 19° | 15° | 11° | 6° | 2° |
| Rain mm | 86 | 66 | 65 | 48 | 51 | 65 | 34 | 38 | 55 | 71 | 63 | 92 |
| Cloud % | 73 | 72 | 65 | 59 | 53 | 39 | 25 | 26 | 40 | 53 | 57 | 70 |
| Wind m/s | 3.7 | 3.9 | 3.8 | 3.3 | 3.0 | 3.1 | 3.6 | 3.8 | 3.5 | 3.3 | 3.2 | 3.5 |
| Daylight h | 9.6 | 10.6 | 11.9 | 13.3 | 14.4 | 15.1 | 14.8 | 13.8 | 12.5 | 11.2 | 10.0 | 9.3 |
| Record high/low | 20°/-13° | 23°/-13° | 27°/-6° | 29°/-3° | 33°/3° | 42°/9° | 41°/13° | 42°/13° | 39°/8° | 36°/-0° | 29°/-4° | 23°/-9° |
| Beach index | 2.6 | 2.8 | 2.8 | 3.0 | 5.3 | 8.4 | 9.5 | 9.4 | 8.9 | 5.4 | 2.9 | 2.6 |
Long-term monthly averages: air from NASA POWER (2001–2020), sea from NOAA OISST (1991–2020); records are the extremes of 2001–2020. How the index works.
When to go
The beach-day index peaks in July–September; July scores 9.5/10 with highs of 29 °C, sea at 23.2 °C and 34 mm of rain.
In July that is 0.4 points above the median of the 156 beaches in Turkey covered by this atlas.
At its warmest the water here is 1.0 °C cooler than the Turkey median for August (25.0 °C).
Across the year the sea averages 15.7 °C, cooler than 70% of the coastal beaches in the atlas.
December is the wettest month (92 mm) and July the driest (34 mm); the yearly total is about 730 mm.
Daylight runs from 9.3 hours in December to 15.1 hours in June; in mid-July the sun rises at 05:42 and sets at 20:32 local time.
Orientation, sun and shore
The shore faces north (0°). Open water fills about 47% of the horizon close by, which makes it an open stretch of shore.
The sun sets over the sea in April–September; in mid-June it goes down at 20:33 local time on a bearing of 302°.
Sunrise is over the sea in April–September.
The opposite shore is only about 8.0 km away to the north, which keeps the water sheltered from big waves.
About 1 km offshore the sea is roughly 70 m deep and 153 m at 3 km, so deep water starts close to shore. Behind the beach the ground is about 70 m above sea level 500 m inland and 172 m at 1.5 km, so the beach is backed by steep slopes or cliffs.
Within 1 km, the land is 59% tree cover, 36% built-up land and 4% grassland (satellite land-cover map, 2021): a partly built-up setting. Water makes up 49% of that circle.
- Tree 59%
- Built 36%
- Grass 4%
Land cover: ESA WorldCover 2021 (10 m). Orientation from OpenStreetMap land polygons sampled in 36 directions; depths and heights from the GEBCO 2020 grid (about 450 m cells), indicative only.
OpenStreetMap shows no lifeguard station within 1 km. Seasonal lifeguard posts are often unmapped, so check on site.
Facilities within 1 km
- 9Restaurants, cafés & bars
- –Public toilets
- –Showers
- 1Drinking water
- 1Car parks
- –Lifeguard stations
- 2Hotels & guesthouses
- 7Grocery shops
- 1Bus stops (1.5 km)
- 2Pharmacies & clinics
Food and drink mapped within 1 km: 4 restaurants, 4 cafés and 1 fast-food outlet. Accommodation: 2 hotels and guesthouses.
Counted within 1 km of the beach (bus stops 1.5 km) from OpenStreetMap features and Overture Maps places, release of 2026-10. Unmapped does not mean absent.
Around the beach
Attractions & museums
- Tepeköy Kültür Merkezi museum 950 m W
Getting there
| Airport | Code | Distance | Direction |
|---|---|---|---|
| Istanbul Sabiha Gökçen International Airport Pendik, Istanbul | SAW | 35.2 km | north-west |
| Bursa Yenişehir Airport Yenişehir | YEI | 49.3 km | south |
| İstanbul Airport Istanbul | IST | 99.1 km | north-west |
Straight-line distances from the beach; road distance is usually 20–40% longer.
Local transport: 1 bus stop within 1.5 km and 1 mapped car park within 1 km.
4 towns and villages of 1,000+ people lie within 10 km (about 40.2K residents); within 30 km there are 33 (about 866.1K).
Map and nearby beaches
Loading map…
Open in OpenStreetMap · Directions in Google Maps
| Beach | Distance | Warmest sea | Length | Surface |
|---|---|---|---|---|
| Altınköy Plajı | – | 24.0 °C | 176 m | Sand |
| Viranbağ Plajı | 46.5 km W | 24.1 °C | 59 m | – |
| Caddebostan Plajı | 56.6 km NW | 24.1 °C | 228 m | Sand |
- Viranbağ Plajı46.5 km WCompare
- Caddebostan Plajı56.6 km NWCompare
Data on this page
- Air temperature, rain, cloud, wind, humidity: NASA POWER climatology 2001–2020, 0.5° grid.
- Sea temperature: NOAA OISST v2.1 monthly normals 1991–2020, nearest ocean cell 43.3 km away.
- Beach outline, surface, rules and public facilities: OpenStreetMap contributors (ODbL), feature w307335301; restaurants, cafés, bars and lodging: Overture Maps places (CDLA-Permissive-2.0).
- Towns and time zone: GeoNames (CC BY 4.0). Airports: OurAirports (public domain). Sunrise and sunset: NOAA solar equations.
- Satellite view: Copernicus Sentinel-2 (ESA), scene S2B_35TQF_20230713_0_L2A.
- Orientation: OpenStreetMap land polygons (ODbL). Depth and terrain: GEBCO 2020 grid.
- Settlements: GeoNames places with 1,000+ inhabitants.
- Land cover: ESA WorldCover 2021, 10 m (CC BY 4.0).
- Search popularity: about 27.1K Google searches a month for the name (KeywordTool, October 2026).
Data compiled 2026-10-13. Something wrong? Report a data error.