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 14°C.
Water Temperature in Tomahawk Lagoon: Daily Trends, Historical Records, and Forecast
⚠️ Lake temperatures between 10 and 15°C are cold but can be manageable for short swims on sunny, warm days. Shallow areas may feel slightly warmer, while deeper sections remain cold and slow to warm up. Most swimmers keep sessions brief, and wetsuits are often used for comfort. Wind and cooler air temperatures can quickly reduce how pleasant the swim feels.
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 9.9°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 |
|---|---|---|---|
| May 6 | 14.5°C | 9.3°C | |
| May 7 | 14.5°C | 9.3°C | |
| May 8 | 14.6°C | 9.3°C | |
| May 9 | 14.6°C | 9.3°C | |
| May 10 | 14.6°C | 9.3°C | |
| May 11 | 14.6°C | 9.3°C | |
| May 12 | 14.5°C | 9.3°C | |
| May 13 | 14.5°C | 9.3°C | |
| May 14 | 14.1°C | 9.3°C | 14.1°C |
| May 15 | 9.3°C | 13.5°C | |
| May 16 | 9.3°C | 12.9°C | |
| May 17 | 9.3°C | 12.3°C | |
| May 18 | 9.3°C | 11.7°C | |
| May 19 | 9.3°C | 11.1°C | |
| May 20 | 9.3°C | 10.5°C | |
| May 21 | 9.3°C | 9.9°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
May 15
May 16
May 17
May 18
May 19
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.