Q.tomato plant blossoms not production fruit
Tomato plant blossoms but there’s no production of fruit.

Certified GKH Gardening Expert
If you are getting flowers but no fruit, really the only issue is pollination. Because of the high heat in much of the country this season, this makes pollinators a little lazier than they should be. Therefore, you may need to hand pollinate to make up for it. This article will help with that: https://www.gardeningknowhow.com/edible/vegetables/tomato/pollinate-tomatoes.htm

Is it too late for them to produce yet this year or should I give up on them? Our temperatures seem to be settling down to more seasonable now. How late can I expect tomatoes if they do finally bear fruit?

You are probably experiencing the same concern many people are having this year. Myself included. Tomatoes will not set fruit at 90 degree and above days.