Milford Sound – current water temperature and swimming conditions

Water Temperature in Milford Sound: Daily Trends, Historical Records, and Forecast

⚠️ This is cool water that may feel brisk on entry. Swimming is usually limited to short sessions, and prolonged stays can become uncomfortable without thermal protection. Many swimmers choose a wetsuit, especially for surfing or open-water swimming.

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 Milford Sound declined overall during the past month, they have shown a noticeable rebound over the last week.

According to our forecast, Sea water temperature in Milford Sound will be 13.5°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

Milford Sound, in Fiordland within the Southland Region, opens to the Tasman Sea but is largely a deep, sheltered fiord surrounded by steep rainforest and towering peaks. Water temperatures here are cooler than many other parts of New Zealand due to depth, limited direct sunlight and high rainfall. In winter, from June to August, surface water temperatures generally range between 8–11°C, which feels very cold and is only suitable for short immersion or for swimmers wearing full thermal protection. Through spring, temperatures rise gradually to around 10–13°C. Summer, from December to March, brings the mildest conditions, with surface waters commonly sitting between 14–17°C. Early autumn can still see 13–15°C before cooling again.