Kai Iwi Beach – current water temperature and swimming conditions

Water Temperature in Kai Iwi Beach: 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 Kai Iwi Beachfell over the past month, but have levelled out during the last week.

According to our forecast, Sea water temperature in Kai Iwi Beach will be 16.3°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

Kai Iwi Beach, just north of Whanganui in the Manawatū–Whanganui region, faces west toward Cook Strait and the Tasman-influenced waters along this coast. Sea temperatures here follow a typical lower North Island cycle. In winter, from June to August, the water generally ranges between 10–13°C, which feels distinctly cold and is usually only comfortable for hardy swimmers or those wearing full wetsuits. Through spring, temperatures gradually lift to around 13–15°C. Summer, from December to March, brings the most inviting conditions, with sea temperatures commonly sitting between 16–19°C during settled weather. Early autumn can still see 15–17°C before cooling again as winter approaches.