There were plenty of delays during India's innings, with the visitors forced to hit out late after a weather break saw the match initially reduced to 40 overs per side.
Another rain delay at the end of the 36th over saw India's innings completed even earlier, with the visitors posting a decent total of 225/3 from their allotted overs.
Opener Shubman Gill was the standout with a career best 98*, while stand-in skipper Shikhar Dhawan (58) hit his second half-century for the series.
Gill was deservedly named Player of the Match and Player of the Series for his heroics during the tour, with the young right-hander scoring two half centuries and a total of 205 runs from three hits.
It goes to show that India are compiling some good depth in their white-ball squads, with Shreyas Iyer, Axar Patel, Shardul Thakur and Yuzvendra Chahal also showing good signs during the three-match series.
Experienced pacer Mohammed Siraj chipped in with two wickets early in West Indies' run chase on Wednesday, while Chahal finished the job by picking up four scalps of his own during an impressive spell.
West Indies' form in 50-over cricket has been surprisingly poor of late, with the Caribbean side now sitting on a nine-match losing streak after consecutive series losses against Pakistan, Bangladesh and now India.
While there were plenty of positive signs in the first two matches of the series against India, the third and final game was completely one-sided as the hosts struggled to match it with their opponents.
Spinner Hayden Walsh picked up two wickets - but conceded 57 runs from his 10 overs - while West Indies' top-order failed to come to grips with India's new-ball bowling attack.
Skipper Nicholas Pooran and right-hander Brandon King each scored 42 in this match, but there were plenty of failures as a disappointing series came to an end for Phil Simmons' side.
Brief Scores: India 225/3 in 36 overs (Gill 98 not out, Dhawan 58; Walsh 2-57) beat West Indies 137 in 26 overs (Pooran 42, King 42; Chahal 4-17, Siraj 2-14) by 119 runs (DLS)
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