What biome is lavitar found in?

Desert apparently,

basically, where geodude, ryhdon spawns i think.

so if you have noticed an area spawning those types, prob there.

I got one in a 10 km egg that I got spinning a Pokestop in Las Vegas, Nevada in the first 48 hours that Gen2 came out. I think it probably was a desert biome there because I noticed a ton more Ekans and Sanshrews there than I see at home ( I think my home is a rock biome because we get a lot of Rhyhorns and Geodudes here but sandshrews are rare other than in nests)

I live in central NC. None here. The only biome that I know of that could have them is the Atlantic Beach/Emerald Isle area of the coast. That place has a very heavy Geodude, Magnatite, Rhyhorns etc. Had plenty of Chanceys and Porygons in the last event too unlike our local area. You can find Dragonites in that area too.

I have found them in 2 different parks, I would say grass biome, lots of Eevees, Vulpix and the lil pink helicopter ones that I ignore

I found one yesterday near my house on a pokestop with a lot of spawns. Only one I've found so far.
We have a lot of rock types here, also machop, mankey and growlithe are common.
I think it spawns in biomes with rock types, but its obviously way more rare than rhyhorn

Saw one this morning, and a Pupitar yesterday. Coastal San Diego.