wire type

I'm installing a solar system, I'm looking to get 10Awg thwn-2 conductors to put in 3/4 emt.

Problem: southwire thhn/thwn does not have the thwn-2 markings.

New 2008 nec req. 90c even in wet conditions.

Southwire specs/sheet reads has if thhn wire cover thwn-2 but it only says thwn.
My understanding was thwn is only good in wet conditions 75c.

#8 wire is available with the marking of thwn-2

Is this something that has come up before? please clarification?