I'm pretty sure it descends? I'm not possible 100% though
The main reason why Earth is warmer at the equator than at the North and South Poles are thats where the sunlight shines at a lot of times. The sunlight never really shines directly at the North and South Poles like it does with the equator.
I would say that the country with the longest average growing season is Saudi Arabia.
I hope this helps you!
