Despite already enduring a relentless barrage of heat, the hot maximum temperatures in Western Australia's southwest are not expected to fade for the next couple of days.

Temperatures in Perth have exceeded 35 degrees for the past five days. A trough developing along the coast has prevented the significant cooling that places in southwest WA are desperate for. With barely any rain, as evidenced by Perth's lean rainfall total of 0.4mm so far in December, these sweltering conditions have been exacerbated.

On Saturday, just before midday, the mercury in Perth reached 41 degrees for the second time this month. In comparison, this time last year in December, the temperature had not reached above 40 degrees and would only do so once, later that month. Further north, Geraldton had a 43 degree maximum, with its current average maximum for December almost 7 degrees above the historical average.

The maximum temperature in Perth is forecast to reach above 35 degrees for another 2 days. If this occurs, it could equal the highest number of consecutive days above the 35 degree threshold in December. The only other time this has occurred at the Perth Metro site was between the 25th and 31st of December in 2012.

Along with these high temperatures comes heightened fire danger. The heat coupled with dry northerly winds has caused an Extreme Fire Danger Rating (FDR) to be issued for Inland Central West-North and Lower West Inland today. Various other districts have a Severe FDR, especially along the coast.

Fortunately, a trough moving east ahead of a front should bring some cooler temperatures for places in the far southwest on Tuesday. However, this respite should only be brief, with temperatures heating up the next day. The front following behind the trough should end the extended spell of hot temperatures on Thursday, but very little rainfall is expected with this system.