Our temps here average 25c or 70f and in the summer (most of the year) we see temps in excess of 35c or 95f. Our roads are very course, they feel much like sandpaper as far as grip.
How lucky!! We're subtropical here in NZ.
Also, oUr roads are mostly very coarse. They are not hotmix/bitumen. They are made by spraying asphalt and pouring gravel on it. As cars drive over them, over time the gravel gets embedded, making a proper road (and for the first few months until then it is basically loose gravel all over).
So the road is very spiky and coarse. This means extra abrasive but with lower tyre temperature overall (all the bad components, eh)
Hence SP would perform a lot better. But, even then, SC performance (in the dry fast road riding) is not bad at all.