Hurricanes and Tornadoes That Hit Iselin, NJ

The nearest NOAA station with 1991–2020 climate normals is Plainfield, NJ, 5 miles northwest of Iselin at 90 feet. July is the warmest, with an average high of 88°F and low of 66°F; January is the coolest, at 41°F and 24°F. July is the wettest at 5.3 inches of precipitation on average and February the driest at 3.1 inches; the year adds up to 48.7 inches over 78 days with at least a tenth of an inch. June to November, the hurricane season months, bring 53% of the year's precipitation (25.7 of 48.7 inches); the other six months are drier. September has brought the most of the 46 tropical systems that passed within 75 miles (21); a normal September there has highs of 79°F and 4.3 inches of precipitation. Highs reach 90°F on about 29 days a year, almost all from May to September. Lows fall below freezing on about 103 nights a year. Snowfall averages 21.4 inches a year, most of it in February. That 48.7 inches is more than at 28 of the 51 New Jersey stations used on this site (55%). Avenel, 2 miles east, has its own station (Cranford, NJ): 50.4 inches a year, 1.7 more than here, and a July average high of 86°F against 88°F.

Water temperature at the NOAA tide station Sandy Hook, NJ, 18 miles southeast, averaged 77°F in July and 38°F in January over 2021–2025. No month averaged 80°F. Sea level at the Bergen Point tide gauge, 10 miles from Iselin, has risen 1.86 ± 0.13 inches per decade from 1981 to 2024, NOAA's linear trend; at that pace it is 18.6 inches in a hundred years. That is faster than at 114 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 680 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Iselin: 363 thunderstorm wind reports, 213 flash floods, 62 floods, 28 lightning strikes and 14 heavy rain events. They killed 15 people and injured 18, and the NWS estimated $109.0 million in property and crop damage. The strongest thunderstorm gust on record here was 86 mph, on May 18, 2000. July has had the most flash floods, 85 of 213. Of the 455 New Jersey cities on this site with a flash flood on record, 342 have had fewer than Iselin.

Flood insurance policyholders in Iselin's ZIP code 08830 have filed 29 claims with the National Flood Insurance Program since 1978, and were paid $1.4 million for buildings and contents, in the dollars of each year. 59% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 395 New Jersey cities on this site with 10 or more claims, 86 have fewer than Iselin.