SUMMER has hit Adelaide early, with temperatures forecast to exceed 33C on each of the next seven days - and the Bureau of Meteorology says there is no end in sight.

Tomorrow, it will be 33C and the maximum temperature is expected to reach at least 35C for the coming week, the Adelaide Advertiser reports.

Temperatures will peak at 37C on Tuesday and Wednesday.

Duty forecaster Hannah Marsh said after tomorrow temperatures will not drop below 20C at night for the coming week.

"There is no significant drop in temperature expected in the outlook period,'' she said.

"This is happening because there is a high pressure system over the Tasman Sea. Because the high is not really moving it will be an extended period of dry, warm to hot temperatures."

Read more at the Adelaide Advertiser online