Day trips by bus from Thessaloniki?
 

The guidebooks seem to assume you'll have a car. I would really rather not drive or try to navigate my husband. Dion, for instance, does not seem to be on a bus route.

Should I wait until I get there, ask at the tourist information?

Have you checked rome2rio.com?

Thessaloniki - Dion: bus to Katherini pluis local bus to Dion
https://ktelpierias.gr/thessaloniki-2/
https://astika-katerinis.gr/en/itineraries

Thessaloniki - Vergina: bus to Verria plus taxi
https://ktelnimathias.gr/?page_id=1516&lang=en

Thessaloniki - Philippi:
Bus to Kavala plus bus or taxi to Philippi

Thesssaloniki - Heracleia:
Bus to Florina plus taxi to Bitola

I forgot about rome2rio, kja. Thank you!

Wonderful, necker. Thanks so much. This will help plan. I drove on excellent Greek highways my last trip there, but this time it would be my husband at the wheel. He gets prickly when i navigate.

it’s far from perfect, but I find useful.

I agree that Meteora is beautiful and interesting ... and IMO, worth a night or two.

But be aware that Thessaloniki - Meteora is a 5-6 hrs bus journey https://ktelbus.gr/tri/ticketweb/
You may also combine it with Vergina and travel via Veria - Grevena

Joan, kja, necker: thank you so much. Meteora looks wonderful. At this point, I kind of doubt we'll get that far, but we'll keep the idea in our back pocket.