After Monday’s downpours inundated roads and disrupted travel, meteorologists warned of a coming heat wave over the next few days. They said high temperatures and humidity levels would drive the heat index into the low- to mid-90s Tuesday and into the triple digits Wednesday and Thursday.

There’s been an abnormal amount of extreme rainfall across the United States in recent days. Here’s what’s driving it.

Severe storms hammered parts of the tri-state area Monday afternoon into the late evening hours, flooding City subways, prompting dozens of water rescues and triggering a state of emergency in hard-hit parts of New Jersey.

Two people died in New Jersey after their car was swept away. Public transit was largely running normally on Tuesday morning, hours after water flooded subway stations and damaged highways.

NYC faces hazardous heat conditions with high temperatures and health risks, as per National Weather Service warnings.

On Tuesday at 1:11 p.m. the National Weather Service issued a heat advisory valid for Wednesday between 11 a.m. and 8 p.m. for Seneca, Cayuga, Onondaga, Tompkins, Madison and Oneida counties.

Numerous flash floods had been reported across New York, New Jersey and Connecticut, closing roads and highways, submerging cars, and stranding motorists, according to the National Weather Service. Metro-North reported suspensions of service on part of the Harlem line, and some delays on the New Haven line, as well, which has since been reopened.