Porirua – current water temperature and swimming conditions

This page shows the current water temperature at Porirua in Wellington Region. You can view recent sea temperature trends on a 30-day chart, check typical monthly water temperature ranges, and compare today’s reading with historical averages for this date. The page also includes a 7-day water temperature forecast, nearby beaches with similar conditions, local weather information, and a summary of swimming conditions to help you assess how suitable the water is for swimming.

Current Sea Water Temperature

12.2°C

Today

12.3°C

Yesterday

12.3°C

A Week Ago

The average sea water temperature today in Porirua is about 12°C.

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

❌ Water at this temperature feels cold and is generally suitable only for brief immersion. Swimming without a wetsuit can quickly become uncomfortable, and exposure time is usually short. These conditions are mainly suitable for experienced swimmers or those using proper thermal gear.

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

From July 28 to August 27

Water temperatures in Porirua 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 Porirua will be 12.3°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Sea Temperature Data

Date	Current	Average	Forecast
Aug 19	12.7°C	12.3°C
Aug 20	12.6°C	12.0°C
Aug 21	12.3°C	12.5°C
Aug 22	12.2°C	12.0°C
Aug 23	11.9°C	12.5°C
Aug 24	11.6°C	12.0°C
Aug 25	11.4°C	12.5°C
Aug 26	12.3°C	12.3°C
Aug 27	12.2°C	12.3°C	12.2°C
Aug 28		12.5°C	12.2°C
Aug 29		12.0°C	12.2°C
Aug 30		12.3°C	12.3°C
Aug 31		12.5°C	12.3°C
Sep 1		12.5°C	12.3°C
Sep 2		12.5°C	12.3°C
Sep 3		12.5°C	12.3°C

* Current - Actual water temperature value

** Average - Average water temperature on this day in recent years

*** Forecast - Our water temperature forecast

Actual near-shore water temperatures in Porirua can vary by several degrees from the values shown, particularly after heavy rain, strong southerlies, or prolonged windy conditions. Certain wind patterns can trigger upwelling, where cooler, deeper water is pushed to the surface and replaces the warmer top layer, leading to noticeable short-term changes in water temperature.

Our water temperature forecast is produced using a proprietary mathematical model that combines real-time measurements with long-term historical patterns, local weather conditions, wind strength and direction, and air temperature specific to each coastal region. To improve accuracy, we cross-check data from nearby locations and use multiple sources, including offshore buoys, satellite-based sea surface maps, and observations provided by local authorities.

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

Porirua sits just north of central Wellington, bordered by the sheltered waters of Porirua Harbour and the more exposed coastline facing Cook Strait. Water temperatures here reflect a mix of tidal influence and relative protection within the harbour. In winter, from June to August, the water generally ranges between 10–13°C, which feels distinctly cold and is usually only comfortable for swimmers in wetsuits. Through spring, temperatures gradually rise to around 13–15°C. Summer, from December to March, brings the most pleasant conditions, with water temperatures commonly sitting between 16–19°C during settled weather. Early autumn can still hold at 15–17°C before cooling again as winter approaches.

Monthly Water Temperature Range (Min, Max & Average)

Month	Min	Avg	Max
January	14°C	17°C	20°C
February	15°C	18°C	21°C
March	14°C	17°C	20°C
April	14°C	16°C	19°C
May	12°C	15°C	18°C
June	11°C	14°C	16°C
July	11°C	13°C	16°C
August	10°C	12°C	16°C
September	11°C	13°C	16°C
October	10°C	13°C	16°C
November	12°C	14°C	18°C
December	13°C	15°C	20°C

* Click on a month to view detailed water temperature data.

Porirua: Weather Forecast

August 28

11°C / 16°C

overcast clouds: 85-100%

humidity: 81% | wind: 40 kmh

August 29

9°C / 12°C

scattered clouds: 25-50%

humidity: 74% | wind: 22 kmh

August 30

7°C / 14°C

light rain

humidity: 72% | wind: 29 kmh

August 31

7°C / 13°C

light rain

humidity: 75% | wind: 32 kmh

Local Water Conditions and Nearby Spots

Swimming Conditions

Swimming is allowed at several locations around Porirua, including Plimmerton Beach and within parts of the harbour when water quality conditions are suitable. The harbour areas can offer calmer water compared to the open Cook Strait coast, making them more appealing for families and casual swimmers in summer. Plimmerton, while more exposed, is a popular spot during warmer months and may have lifeguard patrols at times. Outside summer, cooler water temperatures mean most people prefer short dips or wear thermal gear. As with much of the Wellington coastline, conditions can change quickly depending on wind and tide. On a settled summer day, Porirua provides a refreshing and accessible coastal swimming experience close to the city.