A catastrophic fire danger rating has been issued for the Gascoyne coast for the first time in five years, as an intense heatwave over Western Australia carries on.

Conditions have been anything but cool for the last week over WA, with temperatures soring into the mid-to-high forties over the last few weeks. Some standout temperatures have been: 

• 42.3°C at Perth on the 25th, its hottest Christmas Day on record 
• 47.3°C at Geraldton on the 25th, its hottest December day in 114 years of records 
• 41.2°C at Bunbury on the 26th, its hottest day of any month in 56 years of records 
• 47.9°C at Mardie on 20th, this month's hottest temperature in Australia so far 
• An overnight ‘low’ of 32.3°C at Port Hedland on 28th, its hottest min of any month in 109 years of records

Thanks to the blistering heat, bone-dry conditions have persisted over much of the state. The dew-point temperature (the temperature at which you would have to cool the air to get it to 100% relative humidity) have fallen below freezing in some parts. At 9am Wednesday, Carnarvon temperature was 39.3°C, with a dew-point temperature of –1.0°C, making for a mere 8% relative humidity.

The final ingredient to catastrophic fire dangers is strong winds, something the state hasn’t been short of during this hot period. Winds have been gusting to 40-60km/h each day for almost every location. While this isn’t anything like the strongest winds the state can see, after many days and weeks in a row of these conditions, there is not much moisture left to slow down blazes.

Image: Fire Danger Ratings and Temperatures at midday WST

Fortunately, a break in the heat is coming over the next few days. A cold front will start to cross the far south on Thursday 30th, drawing the hot air into the WA interior and away from the coasts. This will allow much cooler and comfortable seabreezes to reach coastal cities and will drastically reduce the fire danger and heat. However, the heat will start to return to coast once more from around Sunday 2nd.