The number was up from 200 last year though the number of accidents declined by 10.4%, Public Health Minister Cholnan Srikaew was quoted as saying by Bangkok Post.
The capital Bangkok and Chiang Rai Province reported the most fatalities, 13 each.
With the celebrations coming to an end and revelers returning to work in Bangkok and other key cities, authorities have assigned police and civilian volunteers to monitor Bangkok-bound highways to reduce the number of road accidents, according to Nation Thailand.
Despite its popularity, Songkran was dubbed the "seven dangerous days" by authorities a decade or so ago to highlight the dangers on the roads during celebrations.