It’s expected the weather event, which can increase rain and spells of hot weather, will meet conditions in December and may continue through to February.

The Bureau reported a 70 per cent chance of La Niña occurring, but said it would be likely to be weak compared to the 2010-2012 event that was classified as a strong La Niña.

The warning comes as southern Tasmania faces some exceptionally hot weather this week and next, while Launceston itself is sweltering through one of the hottest Novembers on record – after starting the month with snow on Ben Lomond.

Hobart is likely to face a heat wave with four days above 25 degrees matching the November record.

In Launceston temperatures are predicted to reach the 30s on Friday and Saturday, with a possible shower predicted on and off over the weekend before the sun returns full-strength on Tuesday.

The hot weather is a reminder for Tasmanians heading outdoors to prepare.

Cancer Council Tasmania chief executive Raylene Cox said there is some confusion over the risks of UV rays and sun damage.

She said any UV rating above 3 means people need to take adequate protection – sunscreen with 30+ rating or higher, long-sleeved clothing, a broad-brimmed hat and sunglasses. Sunscreen needs to be applied 20 minutes before going outside and reapplied every two hours.

New research shows Australians are still not taking the necessary steps to protect themselves from the sun. The latest Cancer Council National Sun Protection Survey shows about 2.7 million adults are getting sunburnt every weekend. 

During National Skin Cancer Action Week from November 19-25, Cancer Council Australia are reminding people of the importance of sun safety, particularly as temperatures soar across the state. 

Melanoma is the most diagnosed cancer in Tasmania: between 30-50 people die from the disease each year. 

“Parents tend to understand the importance of protecting their children but need to remember to look after them also,” Ms Cox said.