Northern Territory – Water Temperature Overview
The Northern Territory combines warm tropical seas with inland rivers and waterholes. Water temperatures remain high for much of the year, especially in coastal and lowland regions, shaping swimming and outdoor water use.
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
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 | 28°C | 31°C | 33°C |
| February | 27°C | 30°C | 32°C |
| March | 27°C | 30°C | 32°C |
| April | 26°C | 29°C | 32°C |
| May | 24°C | 28°C | 32°C |
| June | 22°C | 26°C | 30°C |
| July | 21°C | 25°C | 28°C |
| August | 22°C | 26°C | 29°C |
| September | 23°C | 27°C | 31°C |
| October | 24°C | 29°C | 33°C |
| November | 27°C | 30°C | 33°C |
| December | 28°C | 31°C | 33°C |
The Northern Territory has some of the warmest sea water temperatures in Australia, shaped by its tropical climate and exposure to the Timor Sea, Arafura Sea, and the Gulf of Carpentaria. Sea water temperatures typically range from around 24–26 °C during the cooler dry season to 28–31 °C in the build-up and wet season. These consistently warm conditions mean the sea rarely feels cold, even in winter, and temperature alone is rarely a barrier to swimming. From a purely thermal point of view, the Territory offers year-round warm water.
Swimming Conditions
Swimming opportunities along the NT coast, however, are influenced by more than just temperature. While the water is invitingly warm, seasonal marine stingers and saltwater crocodiles affect when and where people can safely enter the sea. During the dry season, when water temperatures sit closer to the mid-20s °C, conditions are generally calmer and visibility is better, but swimming is usually limited to designated areas or controlled environments. In the wet season, sea temperatures peak near or above 30 °C, making the water feel almost bath-like, though increased rainfall and runoff can reduce water clarity.
Most Viewed Sea Places in the Northern Territory
Current Water Temperature in Lakes and Rivers
Inland, the Northern Territory offers a very different swimming experience, with water temperatures that can vary widely depending on location, depth, and season. Rivers, waterholes, and natural pools tend to warm quickly under intense tropical heat. In the dry season, inland water temperatures commonly sit between 22 and 28 °C, creating comfortable conditions for swimming, especially during the middle of the day. Shaded waterholes may feel cooler, while shallow pools exposed to the sun can become noticeably warm.
During the wet season, inland water temperatures often rise further, sometimes exceeding 28 °C, but swimming conditions become more unpredictable. Increased water flow, strong currents, and flooding can temporarily lower temperatures and reduce safety. As the dry season progresses, water levels drop and temperatures stabilise, offering the most reliable inland swimming conditions of the year. Overall, while the Northern Territory’s waters are among the warmest in the country, seasonal changes strongly influence where and when swimming is most suitable.
Popular Lakes
- Great Lake12°C
- Little Blue Lake19°C
- Lake Hume22°C
- Tingalpa Reservoir26°C
- Lake Bonney Riverland25°C
- Lake McKenzie25°C
- Lake Bonney SE20°C
- Blue Lake20°C
- Lake Cargelligo25°C
- Lake Ainsworth24°C
- Currimundi Lake24°C
- Avoca Lake24°C
Popular Rivers
- Gordon River15°C
- Goulburn River21°C
- Tweed River21°C
- Nerang River22°C
- Darling River24°C
- Jerrabomberra Creek19°C
- Molonglo River19°C
- Gudgenby River18°C
- Margaret River20°C
- Paroo River26°C
- Cooper Creek26°C
- Warrego River26°C