Tomatoes not turning red

[tumbleweed]

I have lots of tomatoes but they are not turning red, some have been there for 3 weeks. Last year this time I had plenty of red ones. Any ideas?

[rainbowgardener]

How hot is it where you are? Above certain temps, the lycopene, carotene, and other compounds start breaking down and they can't ripen.

Here's a thread with a more detailed answer.

https://www.helpfulgardener.com/forum/viewtopic.php?p=87243&highlight=tomatoes+heat