Profit is down for The Warehouse Group.

The group, which runs The Warehouse, Warehouse Stationery and Noel Leeming has reported an adjusted net profit after tax result of $37.2 million in its half year results.

That's down nearly 20%.

It says the lower net profit is largely a result of softer trading performances at The Warehouse and Noel Leeming.

That softer trading is put down a late start to summer trading and the Digital Switch Over affecting sales in the entertainment and consumer electronics categories.

But it says online sales for The Warehouse or its 'Red Sheds' grew 30% over summer

It says a product was shipped from The Warehouse Group every four seconds in December, with internet traffic showing more than 1.3 million unique users in a month.