when to apply.

I am an international student who intends to apply cornell as a transfer students for AEM major. When I checked CALS site. "preference will be given to students who apply in the fall of their sophomore year.’ was displayed.

Considering I started my freshman year in july 2015 when should I apply? October 2016 or march 2017?

If you started freshman year in Jul 2015, your sophomore fall semester will be Jun 2016. Application for Fall 2016 semester will be due early. I don’t know that schedule but they should have that on website.