FloodZoneMap.org

Flash Flood — Ontario, NY

Jun 18, 2025

Showers and thunderstorms developed along a Lake Erie lake breeze boundary during the late morning of June 18th. With the very high moisture laden airmass over the area, heavy rain occurred within some of the showers and thunderstorms that developed. Some of the thunderstorms, especially early, trained over the same area long enough to cause flash flooding issues. Additional showers and thunderstorms developed during the afternoon ahead of a slow moving cold front over Lake Ontario, causing addi

Source: NOAA National Weather Service Storm Events Database (event 1273921). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Ontario, NY

This event is one of many recorded floods in Ontario County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.

View Ontario County flood data →

More Flood Stories

Flash Flood$200K damage

Ontario, NY · Aug 18, 2019

Several areas of weakening convection moved through the area during the morning. Following this, debris clouds slowly eroded and allowed moderate instability to develop.

Read the full account →
Flood$100K damage

Ontario, NY · Apr 2, 2005

Deep low pressure over Pennsylvania brought copious amounts of precipitation to western and central New York...falling mainly as rain across much of the area. Rainfalls totals generally ranged from two to three inches. The rain, combined with snowmelt, produced flooding.

Read the full account →
Flash Flood$20K damage

Ontario, NY · Jun 20, 2019

Though the primary west to east oriented frontal boundary with upper 60s to low 70s dewpoints streaming into it remained south across Ohio and Pennsylvania, a deepening low pressure system crossing New York State and a very moist air mass resulted in a dynamic moisture-laden…

Read the full account →
Flash Flood$50K damage

Ontario, NY · Jul 13, 2017

A convective complex moved across Western New York late in the morning. This produced a quick 2 to 4 inches of rain which covered a significant portion of the region and resulted in flash flooding that impacted the Buffalo metro area, the Boston/Wyoming hills and parts of the…

Read the full account →