It usually is in that manner, as track temperatures rise, softer compounds generate more heat and will tend to lose performance. Harder compounds will generate less heat and wont lose performance.
you have the right idea. But sometimes Cold situations make tracks increase grip levels, thus a harder compound will be used.
Kamikaze Toys and Hobbies. www.kamikazetoysandhobbies.com / www.kamikazercracing.com