Just ask West Dapto postie Bryan Nicoll, who has custom-made cut-off pants to deal with the heat.

"This is the second version so far, with the cut off legs, that my daughter helped me design," Mr Nicoll said on his mail run yesterday morning.

The hot weather is not the only thing this letter-bearing Santa has to contend with.

"After Friday's downpours, my beard got a little wet. It was drooping, so I had to get a new one," he said.

"But on a cold day (the suit) keeps you nice and warm."

Mr Nicoll has adorned his bike with Christmas decorations for the past five years and dressed up as Santa for three.

He said it took about 20 minutes to get the bike ready each morning, but it was worth it for the joy it brought the community.

"I do it for a bit of fun, to put some smiles on people's faces," he said.

"Everybody who comes out loves it. They're forever blowing horns, waving, and smiling."

Mr Nicoll says the smiles on kids' faces is reward enough, but he receives actual treats as well.

"One little girl made me a card with a photo on the front of her and her little brother and sister," he said.

"They come out with chocolates and bits and pieces for me."

There are a number of other Santa posties around the Illawarra, including Albion Park's Danny Bagnarol.

After years of dressing up, some of Mr Nicoll's decorations look a little faded, but each year he searches around the house and uses whatever he can find.

"I need to jazz these guys up a bit," he said, of the Santa figures on the side of his bike.

"It doesn't take too much to put all the stuff on and away we go, ho, ho."