The rain has finally made its way to Christchurch after scorching temperatures reached 34.5C.

The sweltering heat on Thursday was the city's hottest day since December 2016 when temperatures reached 36C.

The city has seen a massive shift in the weather overnight, reaching a low of 11C with scattered showers on Friday, says MetService meteorologist Tui McInnes.

Meanwhile, the king tide which peaked at 8am on Friday has caused flooding in some low-lying streets around the Heathcote and Avon rivers.

The tide was 12cm higher than the record-breaking high tide last July that caused extensive flooding around the Heathcote River.

Forecasters predict that Friday evening's high tide will be lower, but it is still likely to cause flooding in some streets.

Christchurch City Council closed several local roads Friday morning and will inspect low-lying roads throughout Friday evening - putting temporary closures in place as necessary.

Scattered rain on Friday is expected to ease by the evening, as the low pressure system pulls away to the south east, Mr McInnes said.

The rain is a relief after several fires broke out on Thursday around Canterbury, including in West Melton, where 10 houses were evacuated, and in a pine tree plantation near Governors Bay Rd.

Both fires were under control by Thursday evening