Nishihama Beach Hateruma — Sea temperature now
Japan's southernmost swim beach.
Very warm water with a light chop and a light breeze — great swimming conditions.
Location
Nishihama Beach Hateruma on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
Monthly sea temperature averages
Typical year-round water temperature, based on regional climatology.
Best time to swim in Nishihama Beach Hateruma
The sea in Nishihama Beach Hateruma peaks in June, when the water averages around 28°C.
The main swimming season runs from January – December, when surface temperatures stay comfortable for extended sessions.
On average, 12 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
The coldest month is typically January at around 24°C, when cold-water swimmers dominate the coast.
Nishihama Beach Hateruma sea temperature history
Long-term climatology for Nishihama Beach Hateruma shows an annual mean sea temperature of 26°C, ranging from 24°C in winter to 28°C at the summer peak.
The seasonal swing is roughly 4°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Nishihama Beach Hateruma, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Nishihama Beach Hateruma sea temperature: frequently asked questions
What is the warmest month to swim in Nishihama Beach Hateruma?
June is the warmest month in Nishihama Beach Hateruma, when the sea averages about 28°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Nishihama Beach Hateruma?
The coldest month in Nishihama Beach Hateruma is typically January, when the water averages around 24°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Nishihama Beach Hateruma without a wetsuit?
The main swimming season in Nishihama Beach Hateruma runs from January – December — about 12 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Nishihama Beach Hateruma?
Nishihama Beach Hateruma stays warm year-round, so most swimmers never need a wetsuit — a rash guard is usually enough for sun and wildlife protection.
What is the average sea temperature in Nishihama Beach Hateruma?
The long-term annual mean sea temperature in Nishihama Beach Hateruma is about 26°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Nishihama Beach Hateruma?
The live reading at the top of this page shows the current sea temperature in Nishihama Beach Hateruma, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Year-round sea temperature
Best swim months: Jan – Feb – Mar – Apr – May – Jun – Jul – Aug – Sep – Oct – Nov – Dec
| Month | Sea | Comfort |
|---|---|---|
| Jan | 24°C | Warm |
| Feb | 24°C | Warm |
| Mar | 25°C | Warm |
| Apr | 26°C | Hot |
| May | 27°C | Hot |
| Jun ⭐ | 28°C | Hot |
| Jul | 28°C | Hot |
| Aug | 28°C | Hot |
| Sep | 28°C | Hot |
| Oct | 27°C | Hot |
| Nov | 26°C | Hot |
| Dec | 25°C | Warm |