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 morning, says MetService meteorologist Tui McInnes.

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

Christchurch City Council has closed several local roads - it is advising motorists to avoid driving through floodwaters - detours are in place in some areas.

Christchurch would have scattered rain on Friday, easing by the evening, as the low pressure system pulled 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.

- NZ Newswire