Went through 3 siding species in 8 years in Connecticut. Here's what actually survives.

My house is in coastal CT, gets nor'easters, 95F summers, and freeze-thaw from November through March. Went through this progression: 1. Started with STK cedar in 2016, cupped within 3 years, needed full replacement on the south wall by year 5. Paint wouldn't hold. 2. Replaced south and west walls with cypress in 2021. Better, but the grade I got had too much sapwood and I'm seeing early rot at the bottom courses already. 3. Finally went with sapele from a specialty hardwood supplier last year for the north wall rebuild. Class 1 durability rating, Janka 1510, and it's been through one full winter with zero movement. They milled it to my exact shiplap profile and shipped direct to CT. The sapele cost for 1x8, expensive yes. But I've spentk replacing cedar twice now. If this stuff lasts 25+ years like the data says (Class 1 = 25+ year ground contact rating per EN 350), I'm done touching my siding. For northeast specifically: you need something with dimensional stability AND rot resistance. Cedar has the stability but not the hardness. Tropical hardwoods give you both. Sapele, Ipe, or Jatoba are your realistic options if you want to install once.