Winter car seat cover

Hi mamas!! I live in Canada and spring has finally made its appearance! Thank god!!!

With that being said- i currently have a winter car seat cover and was wondering when you guys think I’d be ok to take it off?

It’s currently ranging between 5-15 degrees (Celsius)... should I wait a bit longer or would I be ok to take it off?

I’m planning on going for walks and my car seat clicks into the stroller - I just don’t want my baby boy to either be cold or over heat... he has a spring suit I’ll be putting him in but I just don’t know until when I should also have his cover. Picture of the cover below! (Picture was taken on our trip home from the hospital- baby boy is now 11 weeks)

TIA xx