The garden city was sitting on 6.5 deg C at 7am on Tuesday, with temperatures not dropping below 7 deg C overnight on Monday.
Radiation fog was causing issues for motorists this morning.
This type of fog usually forms overnight or in the early morning during the coldest hours of the day, and then dissipates after the sun comes up.
Seven flights in and out of Christchurch were cancelled or delayed on Tuesday morning.
The cancellations include flights to Auckland, Hokitika and Tauranga.
A Christchurch Travel Information Team spokesperson said it should clear later for a fairly warm afternoon.
It suggests motorists turn on their headlights, not parking lights, and adjust their speed to have clear visibility of the road at all times.
They should also keep a generous following distance between them and the car in front.
MetService is predicting temperatures will reach 17 deg C in Christchurch on Tuesday.
It is forecasting low cloud and possible drizzle from late evening with a light southwesterly.
MetService predicts rain every day this week.
Temperatures are expected to reach 13C on Wednesday, 11C on Thursday and 10C on Friday.