Climate of Tennant Creek

Tennant Creek Tennant Creek lies within the tropics and as such , has two distinct seasons. However, its position deep within such a large land mass limits the amount of moisture available for the generation of "weather".

Tennant Creek's wet season is limited, with the best averages in December, January and February. Combined, the rainfall in these months constitutes on average more than half of the annual rainfall received in Tennant Creek (the average annual rainfall is 458.8mm). Generally speaking, rainfall at this time is the result of showers and storms which develop from moisture brought in by the large 'heat lows' produced over northern Australia in summer. Heavy falls can result, especially if the 'monsoon trough' migrates into the central Northern Territory. Seasonal tropical cyclones in the Gulf of Carpentaria or Indian Ocean may assist it to do this.

The prevailing wind is from the southeast, which for much of the year is travelling over a dry land mass and so carries little moisture. During the dry season these winds, circulating around the high pressure areas along the south coast, can carry the cold southern air right through the interior, to the north coast, drying it as they go. Despite this low level south-easterly wind, winds at higher levels in the atmosphere are usually from the west or northwest and even in the dry season can carry moisture from the Indian Ocean right across the continent in the form of northwest cloud bands. These cloud bands can be quite substantial and provide falls of rain, though the dry lower levels often evaporate it again before it reaches the ground.

May, June, July and August are the coolest months in Tennant Creek. In these months the average maximum temperatures are below 30°C. In contrast to this, September through to April, exceed 30°C for the average maximum temperatures. The coldest month is July, with temperatures range on average from 12.2°C to 24.5°C. The hottest month is December when the average maximum temperature is 37.3°C. The highest temperature recorded in Tennant creek was 44.7°C and this occurred in December.

November through to March are the cloudiest months when generally half the sky is covered. The hours of sunshine received in Tennant Creek are largely determined by the cloud cover and as such the days when the most sunshine occur are from July to October (that is when there is least cloud cover).

Evaporation rates in Tennant Creek are least during the months of May, June, July and August when the daily evaporation rates do not exceed more than 10mm per day. September through to April have evaporation rates that exceed 10mm per day. The month that experiences the highest evaporation rate is November with an average of 13.9mm per day.