Several NYC subway stations flooded on Monday night after rain drenched parts of the city, causing severe delays and even closures.

The heavy downpours wreaked havoc across the city with footage showing commuters overwhelmed by floodwaters in various subway stations.

MTA Chairman and CEO Janno Lieber is calling on New York City to build up its sewer system after massive subway flooding during Monday's storm​.

"Heads up, New Yorkers," Mayor Eric Adams said in a social media post Tuesday. "We could see another heat wave starting tomorrow, meaning multiple days of dangerous heat." Start the day smarter. Get all the news you need in your inbox each morning.

Transit agencies in the New York City area were promising a fairly smooth commute with some lingering delays on Tuesday, the morning after heavy rain pummeled the region, flooding parts of the subway system, inundating major roads and causing long flight delays.

New York City’s subway system is fully operational following overnight heavy rains. But some roads in New York and New Jersey remained closed for the Tuesday morning commute and there were dozens of flight delays and cancelations at area airports,