The Bureau of Meteorology expects Sydney to be "cool and cloudy" on Christmas Day.

Temperatures across Sydney on Monday will be a little below average and significantly lower than the "run of fairly warm weather" that the area has experienced recently, said senior forecaster Jake Phillips.

"We're thinking a maximum of 23 [degrees] in the city and a bit warmer [around 25] in the west," he said. There will be a couple of showers, likely in the morning, with a cool wind pushing through from the south to south-east.

Christmas Eve, by contrast, will have temperatures as high as 41 in the west, and around mid 30s in the city. But a "gusty cool change" will come through either in the late afternoon or early evening, with a risk of a couple of showers or a thunderstorm.

Sydney will experience a big drop in temperature – 22 to 25 – after the change. The drop will happen within an hour or so, and will hit coastal areas along the south and east before it does the western suburbs.

Weather forecast for Christmas Day

• Sydney CBD: 19 to 23 degrees
• Penrith: 18 to 25
• Liverpool: 18 to 24
• Terrey Hills: 18 to 22
• Richmond: 17 to 25
• Parramatta: 16 to 23
• Campbelltown: 16 to 24
• Bondi: 19 to 20