My old Accord suddenly stalled in the middle of the road (It was extremely dangerous. It caused lots of traffic). While I was driving, the battery and ABS warning lights came on the dashboard, and the engine suddenly shut off completely. The symptom felt very similar to a drained battery and I couldn’t start the car again, but there was no crank sound, like what you'd expect from a dead battery. However, after waiting about 30 minutes for a tow truck, the car started again without any issues.

This shows the battery or alternator is not the problem about this. The battery was replaced about 1.5 years ago, and both the battery and alternator tested fine at O’Reilly after this problem.

The weather was extremely hot (over 90 degrees), and I had the AC running at full blast. I drive the car daily. What do you think could be causing this issue?

 

On a hot day with AC, battery light popped up randomly for a second few weeks ago, my car drove fine and haven't noticed that issue again.
I am wondering about the same, hope someone shed some light on this.

In your case, it can only be the alternator or some power supply circuit giving up when too hot. Main relay comes to my mind.

 

Do you have a lot of keys/charms/etc on your key chain?
At this age the plastic ignition switch can wear out and begin to fail.

Start the engine.
Watch the tach.
Start jiggling the key, up/down/left/right. Don't turn the ignition, just jiggle while watching the tach.
If you see the tach dip and/or the engine cut out, then your ignition switch is begining to fail and will need to be replaced.
It's not hard to replace, switch costs $15-45 depending on which year of Accord.

This is the ignition electrical switch.
Not the $$$ key tumbler, no need to rekey or locksmith.

You can put off the replacement if your key ring is heavily laden. Just use the Ignition key by itself, put a leather key fob on it so it won't get easily lost.