While most of Australia’s east coast is already experiencing a hot and sticky summer, Sydney’s unusually temperate weather is on track to make records, with the city poised to have its longest spell of days under 30C in over a century.
Thursday became the 325th consecutive day the temperature recorded at Observatory Hill, in the heart of the city, stayed under 30C, with the last day recorded above that being 21 February 2022.
This is the longest time in three decades the city has stayed this cool, and is now just 14 days off the record 339-day streak established between 31 December 1882 and 6 December 1883.
With Victoria and parts of Queensland experiencing heatwave conditions, Bureau of Meteorology forecaster Jonathan How said it “was significant” to have so few days above 30C in Sydney.
“Normally you would expect to see 16 days above 30 degrees [in a year], but last year there were only seven and they were all recorded before 21 February,” How said.
The city is forecast to hit 29C on Sunday, and expected to edge over 30C next Wednesday, which would pull it short of setting a record.
It is already the longest stretch in three decades of sub-30C temperatures, according to Weatherzone.
“As for when we can expect the next 30-degree day, it could be as early as this coming Sunday (15 January) while another surge of warmth is expected next Tuesday ... At this stage, both days are tipped to peak at 29C,” Weatherzone said in a statement.
“If both days fall short of the 30-degree barrier, Sydney will be sitting on its second-longest sub-30C streak. If we make it to 28 January without reaching 30C, it’ll officially be a new record.”
Other parts of the Sydney metropolitan region have experienced multiple days of 30C or higher since last February, but the CBD has remained cool because of La Niña and winds coming in from the East, How said.
“With La Niña, you see increased cloud cover and rain,” he said.
“2022 was Sydney’s wettest year on record, we had significant flooding in March and then again in July. It’s been a really wet and damp year.”
Normally the winds blow westerly, picking up hotter inland temperatures from the Blue Mountains as they come down into the city, but this year the winds coming into Sydney have predominantly come from the east, meaning they are cooler because of the water temperature in the Tasman.
“We need those winds from the west to heat up,” How said. “But we didn’t see that this past year, a lot of the winds were from offshore and had cooling effects.”
The temperate weather is bucking global warming trends, with the World Meteorological Organisation announcing on Thursday that the past eight years were the warmest on record globally, fuelled by ever-rising greenhouse gas concentrations and accumulated heat.
The average global temperature in 2022 was about 1.15C above pre-industrial levels, with 2022 becoming the 8th consecutive year that annual global temperatures have reached at least 1C above pre-industrial levels.
For Sydneysiders, there may be some good beach days on the horizon, but How says those itching for a hot summer will have to be patient.
“La Niña is weakening off, and we are seeing signs indicating we will start to see it warming,” he said.
“It’s more likely to be gradual. We just need to be patient and hopefully we get to see some hot summer days soon. More generally, La Niña is expected to be done with; we are heading into neutral conditions.”
