The railroad track connecting Montevideo with Colonia and with the northwest of the country passes through the city.

The river Río San José flows along the northeastern and eastern limits of the city.

Increased precipitation as a result of climate change and impermeabilization of the local land surfaces has made San José de Mayo more prone to flooding over the 1987–2017 period.

It had acquired "Villa" (town) status before the independence of Uruguay, which was elevated to "Ciudad" (city) on 12 July 1856 by the Act of Ley Nº 495.

Its economy is linked mainly to cattle ranching, and it is an agro-industrial centre for dairy products, packing houses, mills, and chemicals.