Posted: 07/08/2015 at 09:05
Anything above low-20s is optimum for ripening. It's the temperature that's key, not direct sunlight. They will ripen in full shade if the temp is right. In good ripening weather, you're looking at roughly 4 weeks to ripe from the time the tom starts to change from dark green to a lighter green.
Temps into the 30s are fine, though you risk plant stress, particularly in an enclosed environment. I've got temps into the 40s up on my terraces, ripening is pretty rapid, and the open-air environment helps with the stress problem. The downside is that flowers rarely set fruit at that temperature so I'm getting fruit that set before the heat hit. It's a little cooler overnight now so fruit is starting to set again.