Manawatū – Whanganui
Manawatū–Whanganui features a coastline as well as numerous rivers and inland lakes. Water temperatures vary significantly by season and location, influencing swimming conditions across coastal and inland areas.
Current Sea Water Temperature
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.
Sea Temperature Trends
Over the past month, the sea water temperature has remained largely unchanged. Overall, the sea water temperature is within the range expected based on historical data for this month.
Water Temperature and Swimming Conditions by Month
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 14°C | 18°C | 21°C |
| February | 15°C | 18°C | 21°C |
| March | 14°C | 18°C | 21°C |
| April | 14°C | 17°C | 19°C |
| May | 12°C | 16°C | 19°C |
| June | 11°C | 14°C | 17°C |
| July | 11°C | 14°C | 16°C |
| August | 10°C | 13°C | 15°C |
| September | 11°C | 13°C | 15°C |
| October | 10°C | 13°C | 16°C |
| November | 12°C | 16°C | 19°C |
| December | 13°C | 17°C | 20°C |
Most Viewed Sea Places in the Manawatū–Whanganui
Current Water Temperature in Lakes and Rivers
About the Region & Location Map
Manawatū–Whanganui stretches from the central North Island plateau down to the Tasman Sea, offering a mix of coastal and inland swimming spots. Along the west coast, summer sea temperatures generally range between 17°C and 20°C, with February often the warmest month. These conditions are usually comfortable for a swim on a fine day, although the water still feels fresh compared with more northern regions. In winter, coastal temperatures commonly drop to around 12°C to 14°C. Swimming is allowed at many beaches, but the exposed coastline is known for surf and strong rips, so it’s safest to swim between the flags at patrolled beaches and pay attention to local warnings.
Further inland, rivers and lakes show wider seasonal variation. In summer, freshwater temperatures often sit between 16°C and 21°C, depending on sunshine, flow levels and recent rainfall. Popular swimming holes can feel pleasantly cool during hot spells. In winter, inland waters frequently fall to between 6°C and 12°C, especially in higher-altitude areas and fast-flowing rivers. Swimming is generally permitted where water quality is suitable and there are no health advisories, as heavy rain can affect clarity and bacterial levels. With sensible precautions, the region offers a range of swimming opportunities, particularly during the warmer months.