I need understanding from my class teacher

Sometimes I am late for school, especially on rainy days or when it is Monday morning.
My home is 12 kilometers from our school, and I go to school by bike. It usually takes me 40 minutes to get to school, but on rainy days I have to ride slowly because I don't want to have accidents. On Monday morning, my road to the school is always crowded with people on foot ordriving or riding. and this sometimes makes me late. When I get to the classroom, I apologize for being late,but my class teacher will still look angry. So I hope she can understand me a little more. Certainly I will try not to be late again.