Many municipalities have introduced restrictions on the time of day hosepipes may be used, reports national broadcaster NRK.
Municipalities in the Telemark, Vestfold, Vest- og Aust-Agder and Østfold counties are affected by bans, according to the report.
Residents are advised to visit municipality websites to check exact restrictions in place locally.
“Water usage has increased sharply during the last week, so we have found it necessary to introduce water restrictions,” technical officer Andre Olsen Lindkjenn of Bamble Municipality in Telemark told NRK.
“We have had to limit water usage so that people living at higher elevations have water in their taps. And we also need access to sufficient amounts of water in case of a fire,” Lindkjenn added.
In Vestfold in the country's southeast, ten out of 12 municipalities have had restrictions implemented.
Town maintenance manager Øyvind Myhre, from the county's Tønsberg municipality told NRK the restrictions were in place to ensure sensible water use.
“If everyone used water at the same time, we would have problems. But the rules are mostly there to make sure people water at the right times and in the right way. If you water in the sun in the middle of the day, most of the water will disappear into the air again,” he said.
Fines of up to 1500 kroner (158 euros) can be given if water restrictions are breached, according to NRK's report.