Not very.
Lexically, a lot of the words aren't Latin or aren't used with the meaning they had in (Classical) Latin: zenithi (French zénith < Medieval Latin cenit < Arabic samt (with the m being misread as ni) < Classical Latin sēmita 'path'), atmospheri (French atmosphère < New Latin atmosphaera from ἀτμός + σφαῖρα, not attested as a compound in Ancient Greek or Classical Latin), autobi and autobibus (French autobus, from automobile + omnibus, both clipped), passebant (French passer < Vulgar Latin *passare, not attested Classically), supradicti (the intended meaning is 'mentioned above/earlier', but as a variant of superdictus it actually means 'said in addition'; splitting off the supra would kind of fix it), junum (French jeune < Latin iuvenis), collo (French col 'collar' as opposed to Latin collum 'neck'), chapito (French chapeau with an Spanish-like diminutive, I guess), a (French à, should be another cum), galono (French galon 'braid') tressato (French tressé 'braided'; Latin would be plexo or similar), cerclaro (not sure what's intended there).
Grammatically, there are a number of issues as well: regionem should be in the ablative, not the accusative; magnissima should be maximus (irregular superlative, agreement with masculine calor); sudebant should be sudabant (sudo is in the first conjugation); passebant should be passabant (assuming reconstructed *passare, first conjugation); supra[ ]dicti should be supra dictis; autobibus should be autobis (second declension), or autobi should be autobus (fourth declension); portebat should be portabat (a trend); multi should be multum (the adverb).
It's possible I missed some. Of course, producing correct Latin wasn't really the point.
His use of autobi did remind me of Alfred Denis Godley's The Motor Bus, which did a better job of sticking to a declension.