Tomahawk Lagoon – current water temperature and swimming conditions
This page provides information about the current water temperature at Tomahawk Lagoon in Otago Region. Here you can view recent temperature trends on a 30-day chart, check typical monthly water temperature ranges, and compare today’s reading with historical averages for this date. A 7-day water temperature forecast, local weather conditions, and an overview of swimming suitability are also included.
Current Water Temperature
The water temperature in Tomahawk Lagoon today is 7°C.
Water Temperature in Tomahawk Lagoon: Daily Trends, Historical Records, and Forecast
❌ Lake water below 10°C is extremely cold and generally unsuitable for swimming for most people. Even during warm weather, deep lakes retain cold water, making entry uncomfortable and limiting time in the water. Swimming at this temperature is usually limited to quick dips or cold-water enthusiasts. Cool air temperatures or cloudy conditions can make lake swimming particularly harsh.
Water Temperature Over the Last 30 Days
Water temperatures in Tomahawk Lagoon have been gradually cooling over the past month, with a further drop recorded during the last week.
According to our forecast, the water temperature in Tomahawk Lagoon will be 8.5°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Water Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| Aug 19 | 15.9°C | 8.7°C | |
| Aug 20 | 15.9°C | 8.7°C | |
| Aug 21 | 15.9°C | 8.7°C | |
| Aug 22 | 15.3°C | 8.7°C | |
| Aug 23 | 15.5°C | 8.7°C | |
| Aug 24 | 15.5°C | 8.7°C | |
| Aug 25 | 7.4°C | 8.7°C | |
| Aug 26 | 7.4°C | 8.7°C | |
| Aug 27 | 7.4°C | 8.7°C | 7.4°C |
| Aug 28 | 8.7°C | 7.6°C | |
| Aug 29 | 8.7°C | 7.7°C | |
| Aug 30 | 8.7°C | 7.9°C | |
| Aug 31 | 8.7°C | 8.1°C | |
| Sep 1 | 8.7°C | 8.2°C | |
| Sep 2 | 8.7°C | 8.4°C | |
| Sep 3 | 8.7°C | 8.5°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual lake water temperatures may differ from the reported values by several degrees, particularly during periods of strong winds or rapid weather changes. Wind can mix surface and deeper layers in a lake, bringing cooler water to the surface, while shallow areas may warm more quickly under direct sunlight. Air temperature, sunshine, and cloud cover strongly influence how quickly a lake heats up or cools down. These factors can lead to noticeable temperature variations across different parts of the lake.
Our forecast is based on a proprietary mathematical model that considers real-time lake temperature observations, historical trends, seasonal cycles, wind strength and direction, and region-specific air temperature. To enhance accuracy, we also incorporate data from nearby monitored locations and comparable lakes within New Zealand.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Today | Yesterday | A Week Ago |
|---|---|---|---|
| January | 11°C | 17°C | 23°C |
| February | 11°C | 18°C | 24°C |
| March | 9°C | 14°C | 19°C |
| April | 3°C | 10°C | 16°C |
| May | 4°C | 9°C | 13°C |
| June | 0°C | 4°C | 8°C |
| July | 0°C | 3°C | 6°C |
| August | 0°C | 5°C | 9°C |
| September | 1°C | 7°C | 13°C |
| October | 5°C | 11°C | 16°C |
| November | 9°C | 14°C | 19°C |
| December | 3°C | 13°C | 22°C |
Tomahawk Lagoon: Weather Forecast
August 28
August 29
August 30
August 31
September 1
Location & Local Information
Tomahawk Lagoon in the Otago Region is a shallow coastal lagoon located just south of Dunedin and separated from the Pacific Ocean by Tomahawk Beach. As a low-lying, sheltered water body, it responds quickly to changes in air temperature. In summer, from December through February, water temperatures typically range between 15°C and 19°C, occasionally reaching around 20°C during settled, sunny periods. In spring and autumn, temperatures are more moderate, generally between 10°C and 15°C. Over winter, the lagoon cools considerably, with water temperatures often falling to around 6°C to 9°C, reflecting the cooler conditions typical of coastal Otago.
Swimming Conditions
Swimming in Tomahawk Lagoon is not officially banned, but it is not widely regarded as a primary swimming spot. The lagoon is relatively shallow, with muddy margins and areas of aquatic vegetation, which can make entry less appealing. Water quality can also vary depending on rainfall and runoff from surrounding urban areas, so conditions are not always ideal for bathing. During warm summer days, some locals may take a brief dip when temperatures approach the upper teens, but most visitors prefer nearby ocean beaches for swimming. Outside the summer season, the cooler water temperatures and natural lagoon conditions generally limit swimming to short immersion rather than extended recreation.