The visitors improved to four wins and two losses on the season.
The Seahawks, who were still without starting quarterback Russell Wilson due to a hand injury, got off to a perfect start when DK Metcalf muscled his way past multiple defenders for an 84-yard touchdown in the only scoring play of the first quarter.
New Orleans hit back in the second, opening the quarter with a field goal before Jameis Winston found Alvin Kamara in the end zone to give the visitors a 10-7 lead at half-time.
As the weather deteriorated in the second half, so did the play on the field as both sides struggled to complete passes.
A crucial fumble late in the third allowed Seattle to even the score, but they were unable to take the lead early in the fourth when kicker Jason Myers missed a 53-yard attempt wide left in the swirling wind.
Ill discipline down the stretch ended up costing the Seahawks, who gave up two late penalties for first downs – the second of which led to the Saints’ game-winning 33-yard field goal.
Winston finished the game with 222 passing yards to go along with 40 on the ground, while Seattle back-up Geno Smith was held to just 167 yards.