Sydneysiders have sweated through the city's most humid week for more than a decade but the good news is the end of the sultry spell is within sight.
A stable weather pattern of a high pressure system in the Tasman Sea and a trough over western NSW have steered a fairly constant stream of moist, warm air over Sydney for more than a week.
Even without high mercury counts on most days, Sydney has had its most humid week in at least 15 years based on readings at the airport, Brett Dutschke, a senior meteorologist at Weatherzone, said.
That humidity "has been pretty uniform right across the city", Mr Dutschke said.
"We've been having these north-easterly winds ... for the past week and they'll last for a couple more days."
For Sydney, tops of 28 and 29 degrees are forecast for Monday and Tuesday in the city.
Western suburbs such as Penrith are looking at 34 and 37 degrees, respectively, for those two days.
The relative humidity remains high, though, making those temperatures feel hotter.
There won't be much noticeable relief until people wake up on Wednesday morning, Mr Dutschke said.
The weather conditions will then turn cooler until about Tuesday next week, with the mercury in the city barely making it to the mid-20s and dropping to as low as 17 degrees on some mornings.
That will be welcome relief after the past week has had some nights with a minimum dropping only to 24 degrees.
Winds from the south will also keep conditions relatively dry, leaving rainfall totals likely to end up shy of half the long-run average for January.
"It will feel quite comfortable," Mr Dutschke said.
"It means you won't have to take a shower when you arrive at work."
For the past week, the so-called "wet-bulb departure" - a measure used to gauge humidity - has been only 2 degrees at the airport, or well below the January average of 4 degrees, Mr Dutschke said.
A wet-bulb departure measuring zero degrees means 100 per cent humidity.
The spell is also unusual at a monthly level. It is also 12 years since Sydney has had a January this humid, with the wet-bulb departure running about 3.3 degrees, he said.
Severe down south
While Sydneysiders may be growing weary of the long humid spell, conditions were more severe for Melbourne over the weekend.
That city recorded a maximum of 38 degrees on Sunday with high humidity, prompting the Bureau of Meteorology to describe conditions as "oppressive".
Melbourne will only get late relief on Monday after a top of 35 degrees, described by the bureau as "sultry".
The hot conditions were broad based, with much of eastern Australia enduring at least a low-intensity heatwave that will start to retreat from Monday.
According to the bureau's heatwave service, most of Victoria and Tasmania will have sweltered through at least severe heatwave conditions by the end of the day.
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