More warm weather is on the way but temperatures are unlikely to climb above 30 degrees Celsius this week.
Cantabrians sweltered yesterday as maximums hit about 31C in many places before the arrival of a cooling sea-breeze mid-afternoon.
It was the first time the temperature had reached into the 30s in Christchurch since early 2011.
Unsettled conditions are expected this week as a developing upper-level trough of low pressure in the Tasman Sea spins frontal systems ahead of it across New Zealand.
That means rain at times for northern and western places but in Canterbury it will be mainly warm with northerly winds until a colder change later in the week.
MetService spokesman Dan Corbett said today would be a quieter day than yesterday with generally light winds and mild temperatures peaking about 20C.
A building north to northwesterly flow tomorrow would push temperatures towards 25C, with Wednesday possibly even a degree or two warmer.
Things would start to cool on Thursday, with a chance of patchy rain, before colder southerlies moved in on Friday with a period of more general rain.
''So your best chance of rain looks to be at the end of the week. Until then, with those northerlies and northwesterlies you're going to have some reasonably warm days.''
The airstream that brought yesterday's 30-plus temperatures originated over southern Australia and was responsible for 34C temperatures in Hobart last Friday.
- © Fairfax NZ News