Bay of Islands – current water temperature and swimming conditions

Water Temperature in Bay of Islands: 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

Water temperatures in Bay of Islands have been gradually cooling over the past month, with a further drop recorded during the last week.

According to our forecast, Sea water temperature in Bay of Islands will be 18.2°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

The Bay of Islands, in the Northland Region on New Zealand’s upper North Island, is a sheltered coastal area made up of numerous islands, sandy beaches and calm inlets facing the Pacific Ocean. Owing to its northern location and protection from the open ocean, sea temperatures here are relatively mild compared with much of the country. During summer, from December to February, water temperatures typically range between 19°C and 22°C, and shallow bays can warm slightly more on sunny, windless days. In autumn, the sea often remains around 18–20°C before gradually cooling. Winter temperatures generally sit between 14°C and 16°C, while spring sees a steady warming from about 15°C towards 18°C as settled weather becomes more common.