Mercer County, NJ Weather Alerts
Every National Weather Service alert issued for Mercer County, New Jersey, pushed to your phone within moments — county code NJC021, forecast zone NJZ015. Free with StormCast.
Download on Google PlayHow the NWS identifies Mercer County
These are the identifiers the National Weather Service uses when it issues a warning here. StormCast watches NJC021 directly rather than matching on place names, which is why an alert arrives whether you are in Ewing or anywhere else in the county.
NWS County Code
NJC021
Forecast Zone
NJZ015
Forecast Office
Mount Holly (PHI)
Radar Station
KDIX
Towns covered in Mercer County
An NWS alert for Mercer County applies to all 9 of these communities. You do not need a separate alert for each one.
River gauges in and around Mercer County
StormCast tracks 8 gauges near Mercer County. Set a flood-stage alert on any of them to get notified before the water reaches you.
Current conditions
Loading current conditions…
Alert types issued for Mercer County
Tornado
Tornado Warning, Tornado Watch, Tornado Emergency and Severe Thunderstorm Warning.
How tornado alerts work →Flooding
Flash Flood Warning, Flood Watch, Flood Advisory and River Flood Warning.
How flood alerts work →Winter
Winter Storm Warning, Ice Storm Warning, Blizzard Warning and Winter Weather Advisory.
Winter warnings explained →Fire Weather
Red Flag Warning and Fire Weather Watch when conditions favor rapid fire spread.
Fire weather alerts →Heat & Cold
Excessive Heat Warning, Heat Advisory, Freeze Warning and Frost Advisory.
Frost & freeze alerts →Mercer County weather alert questions
Which NWS forecast zone is Mercer County in?
Mercer County, New Jersey is NWS county code NJC021 and forecast zone NJZ015. Alerts for it are issued by the Mount Holly (PHI) Weather Forecast Office, and the nearest NEXRAD radar is KDIX.
Which towns in Mercer County are covered?
All of them. NWS alerts are issued at the county and zone level, so a warning for Mercer County covers every community inside it, including Ewing, Hightstown, Hopewell, Pennington, Princeton, Titusville, Trenton, West Windsor and Windsor.
Are there river gauges in Mercer County?
Yes — StormCast monitors 8 river gauges in and around Mercer County, including Assunpink Creek at Clarksville, Stony Brook at Princeton, Shabakunk Creek at Ewingville. You can set a flood-stage alert on any of them and get a push notification when the water rises.
How fast are alerts for Mercer County delivered?
StormCast polls the NWS alert feed every 30 seconds. When a warning is issued for NJC021, the push notification goes out within moments — even with your screen off.