Most of the resorts have a good layer of machine made snow topped up with a further 5-15cm (2 - 6 inches) of fresh powder during the weekend.
Besides Geilo, some of the other big resorts to open were Kvitfjell and Skeikampen.
Trysil had hoped to open but unfortunately warm winds blew in and stopped them from adding the extra artificial snow they needed.
Last week was not great for any snowmaking, but colder nights towards the end of the week, and a promising snow forecast managed to help those first skiresorts to open a few slopes.
Gaustablikk, Bjorli, Strandafjellet, Kongsberg, Uvdal and Gålå were the other ski areas to open.
According to Snowfinder there are currently nearly 40 ski resorts in Norway who got or will get fresh snow in the last three days or will do so in the next four days.