New York City is bracing for another round of heavy rain and potential flash flooding Monday, as a low-pressure system moves through the region and threatens to disrupt the morning and afternoon commute just weeks after a series of storms submerged streets and subway stations across the five boroughs.
The New York City Emergency Management Department issued a weather alert Sunday advising residents to prepare for periods of heavy rain, scattered thunderstorms, and the potential for localized flash flooding on Monday, Aug. 3, as the system moves into the region.
When the storms will hit
According to the National Weather Service, isolated showers were expected to develop Sunday ahead of the approaching low-pressure system, with rain becoming more widespread Monday morning. NYCEM’s alert identified the greatest risk window for heavy rainfall and thunderstorms as falling between 10 a.m. and 6 p.m. Monday, directly overlapping with the workday commute for much of the city.
NBC New York‘s weather team offered a similar timeline, reporting that the main threat would begin after Sunday dinner and continue through Monday, with rounds of thunderstorms bringing heavy rain and likely flash flooding into the Monday afternoon commute as well.
While rain is not expected to fall continuously throughout the day, city officials cautioned that individual thunderstorms could produce rainfall rates of 1 to 2 inches per hour, intensity capable of triggering isolated to scattered flash flooding in urban areas, locations with poor drainage, low-lying neighborhoods and along streams that respond quickly to heavy rain. Showers are expected to taper off by early Monday evening, according to the NYCEM alert.
A summer defined by repeated flood threats
Monday’s forecast extends what has become a recurring pattern across the city this summer. Just days earlier, on July 27, New York City and Philadelphia sat at the center of what CNN described as a “serious” Northeast flash flood threat, with more than 35 million people placed under flood watches as an unusually strong storm system threatened to drop more than a month’s worth of rain across parts of the region.
That storm brought widespread rainfall totals of 3 to 5 inches, with isolated spots seeing up to 7 inches, an amount that CNN noted exceeded New York City’s average total rainfall for the entire month of July, which stands at 4.60 inches. The New York Post separately reported that the city was placed under a flood watch that same week, with Gov. Kathy Hochul urging residents to prioritize safety ahead of the anticipated downpours.
Even earlier, on July 4, city officials mobilized a full emergency response ahead of a severe weather system expected to bring torrential rain and widespread flash flooding beginning Sunday evening and continuing through the following Monday night, according to Fox5 New York. Meteorologists at the time warned of peak rainfall rates between 2 and 3 inches per hour, intensity capable of causing rapid, life-threatening flash flooding, with the highest-risk window falling between 4 a.m. and 10 a.m. that Monday, directly threatening the morning commute.
Why the city keeps flooding
Officials and meteorologists have pointed to a specific infrastructure vulnerability behind the repeated flooding: New York City’s stormwater drainage system is generally built to handle rainfall rates only up to about 1.75 inches per hour, a threshold that CNN reported is being surpassed with increasing frequency during this summer’s storms. When rain falls faster than that, water backs up in streets, low-lying neighborhoods, highway underpasses and subway entrances far more quickly than the system can absorb it.
That dynamic has repeatedly overwhelmed drainage infrastructure across the five boroughs this summer, contributing to the kind of dramatic street flooding, stranded vehicles and subway disruptions that have characterized several storms since early July.
What officials are telling New Yorkers
NYCEM’s Monday alert reiterated the same core safety guidance the department has issued repeatedly throughout the summer. Residents living in basements, ground-floor apartments, or neighborhoods with a history of flooding were told they face higher risk and should not wait for water to enter their homes before acting, since floodwater can rise too quickly to evacuate safely once it arrives.
The department urged residents to sign up for real-time alerts by texting “NotifyNYC” to 692-692 or visiting the city’s Notify NYC webpage, and reminded New Yorkers that they do not need to wait for an official warning to begin preparing once heavy rain appears in the forecast. Anyone in immediate danger or trapped by rising water was told to call 911 immediately, while non-emergency issues such as blocked catch basins or downed trees should be reported through 311.
Officials also repeated longstanding flood-safety guidance: never walk, swim, or drive through floodwater regardless of how shallow it appears, avoid returning to a flooded area even after leaving it since conditions can change rapidly, and check on elderly neighbors or those with disabilities who may need extra assistance preparing for the storm.
During previous storms this summer, city leadership has echoed those same directives publicly. During the July Fourth weekend flooding event, officials urged motorists and pedestrians to limit travel during peak rainfall hours and to rely on public transit rather than driving through affected areas, while asking property owners to secure loose outdoor furniture and trash bins that could become windborne hazards or block street drains.
What comes next
With storms expected to move through the region between Monday morning and early evening, city officials are urging residents to monitor conditions closely throughout the day rather than assume the risk has passed once initial showers subside. Given the pattern established over the preceding month, in which announced flood watches have repeatedly escalated into flash flood warnings and localized emergencies, meteorologists and city emergency planners are treating Monday’s system as a continuation of an unusually active and disruptive flooding season for the city, rather than an isolated event.