starting problems?

hi guy, i have a problem with my vaxhall zafira, 1.6club, 57reg.The problem is that it won't start in the cold weather first thing in the morning but starts fine any other weather. The engine will turn and after a few minute it starts up like there wasn't a problem with it, it runs fine all day
It's only has problem when it is cold over night and the tempreture drop below 7c
Can anyone let me know the problem, as drop the children to school and worried that it might not start in the morning. thank you