Onemana – current water temperature and swimming conditions

Water Temperature in Onemana: Daily Trends, Historical Records, and Forecast

⚠️ Water in this range feels cool but still manageable for many swimmers. Short to moderate swims are comfortable, especially in warm weather. Some people may prefer a wetsuit for longer stays, particularly when swimming actively or outside peak summer conditions.

It’s important to note that these swimming tips and recommendations apply only in settled weather. When air temperatures drop below 20°C — and sometimes even below 25°C — swimming can feel uncomfortable, even when water temperatures are relatively high.

Water Temperature Over the Last 30 Days

While water temperatures in Onemana declined overall during the past month, they have shown a noticeable rebound over the last week.

According to our forecast, Sea water temperature in Onemana will be 18.9°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Sea Temperature Data

Annual Water Temperature Overview by Month

Monthly Water Temp Ranges

30°C

25°C

20°C

15°C

10°c

5°C

0°C

Annual Water Temperature Trend

Onemana is a small coastal settlement on the eastern side of the Coromandel Peninsula in the Waikato Region, facing the Pacific Ocean. The beach is relatively compact and framed by rocky headlands, which can provide some shelter from larger swells compared with more open stretches of coast. In summer, particularly from January through March, water temperatures generally range between 19 and 22°C. Most locals find this comfortable for swimming on warm, settled days, although a fresh onshore breeze can make the water feel cooler. During autumn, temperatures ease back to around 17 to 20°C. Winter brings cooler readings, typically between 14 and 16°C, while spring sees a gradual rise from roughly 15 up to 18°C as the season progresses. Wind and ocean swell can cause short-term surface variations.