Rain ruins Sri Lanka's final ODI against New Zealand
As the rain refused to relent, the umpires officially called off the game at 19:45 local time (1415 GMT).
The game was a dead rubber with Sri Lanka already having clinched the series 2-0, following their thrilling three-wicket win on Sunday.
The victory was Sri Lanka's fifth one-day series win in the year.
"We had a very good year," said Sri Lanka skipper Charith Asalanka.
"We have put in lot of hard work this year," he said. "We wanted to give players a fair run and that faith is paying back."
Before the rain hit, New Zealand seemed set for a decent total after winning the toss and deciding to bat first.
A solid 88-run partnership for the second wicket between Will Young and Henry Nicholls propelled them to 112 for 1 in 21 overs before it started pouring.
Young was unbeaten on 56 off 68 balls. The right-handed batsman's half-century, his ninth in one-day internationals, featured eight boundaries.
At the other end, Nicholls was 46 not out off 51 balls.
New Zealand captain Mitchell Santner called the washout a "shame".
"We had a good start and it was a pretty good wicket," he said. "We were eyeing a big score."
Sri Lanka managed an early breakthrough when Asalanka pulled off a sensational diving catch to dismiss opener Tim Robinson, handing Mohamed Shiraz his maiden international wicket.
But New Zealand consolidated from there on.
Having achieved an unassailable lead heading into the match, the hosts rested Pathum Nissanka, Kusal Mendis, Kamindu Mendis and Asitha Fernando.
Left-arm spinner Dunith Wellalage was also given a break, with seam-bowling all-rounder Chamindu Wickramasinghe making his debut.
New Zealand, too, shuffled their lineup, bringing in pacer Adam Milne and debutant all-rounder Zakary Foulkes in place of Nathan Smith and Jacob Duffy.
Foulkes, however, did not get a chance with the bat or the ball.
The one-day series followed a T20 series that ended in a 1-1 stalemate.
New Zealand will now host England for a three-match Test series starting later this month.
"We will go back home and get ready for that series," said Santner.