Gunnedah residents were out and about on the public holiday, enjoying the sunshine at Porcupine Lookout and Wolseley Park.
Before the sun made an appearance on Monday, the north west was blanketed in a thick layer of fog as far as the eye could see.
But Facebook page Tamworth Region and Weather's David Farrenden said the fog would pass as soon as a cold front came through.
"Fog needs virtually zero winds and calm conditions over night, [so the] cold front will be too much wind for fog," Mr Farrenden said.
"The last couple of days it has been widespread, especially on the slopes, and then this moves onto the plains as well."
Mr Farrenden said the formation of fog was "usually to do with the temperature inversion in the upper atmosphere to lower atmosphere".
"You get fog after rain, but mostly in Tamworth and Gunnedah where you don't get a lot of fog, it's to do with the temperature inversion," he said.
"There is a fair bit of moisture in the atmosphere but it's just a cloud on the ground."
While a cold front is expected, the weather chaser told the NVI it would be "too warm for snow".
"With cold fronts, dry air usually follows, [but for snow] you need cold air and moisture," he said.