For the 13th consecutive year, we in the state climate office have evaluated the myriad daily, monthly, and annual observations gathered across New Jersey during the course of the year to choose what we feel were the most significant and impactful 10 weather and climate events of 2021.

November was the first month since May 2020 with both averages of precipitation and temperature below 1991–2020 normals.

October was the second mildest on record in the Garden State since records commenced in 1895. This follows on the heels of the 11th warmest September, leaving most residents wondering when cool weather would arrive and leaves would turn and fall. For the first time since at least 1900, not a single weather observing station in New Jersey recorded a freezing low temperature on any day in either September or, as is climatologically most common, October. All of this resulted in a leaf season that was delayed by one to two weeks.

Post-tropical storm Ida. The title of this month’s report speaks to this momentous weather extreme that will forever be the defining event of this month and likely the entire year. The storm delivered the most powerful tornado to strike the Garden State since 1990, demolishing multiple homes in Gloucester County. Rainfall exceeding 3.00” per hour led to the most widespread flash flood event on record for the state, resulting in the tragic deaths of 30 individuals in central and northeastern locales.

Post tropical storm Ida moved across the Garden State during the afternoon of September 1st into the early hours of the 2nd. It brought with it torrential rainfall, leading to flash and river flooding that took the lives of approximately 30 individuals and the rescue of countless more from raging waters. Additionally, it brought three tornadoes to southwestern and central areas, including the first EF-3 twister to strike New Jersey in 31 years. There were only minor injuries and no deaths from the tornadoes.

Ida’s Path

Whether the thermometer was reading high or low this August or whether rain was falling or not, one factor that most always had to be considered was the high level of humidity. The “Dog Days” of summer indeed. Of course, there was much else to consider this month, including contributions of rain from two tropical storms, one of which brought the largest crests on some rivers since May 1, 2014, 11 days where one or more locations received at least 2.00” of rain, and 16 days where the high temperature reached 90° or higher somewhere in the state.

Wow, what a month. July 2021 provided a never-ending cascade of weather events, including a tropical storm, a record-tying number of tornadoes, large hail, flash floods, hot days, chilly nights, smoke-filled skies, and on the last day of the month, perhaps the nicest day of the summer. The statewide average precipitation of 7.59” was 2.88” above the 1991–2020 normal and ranked 8th wettest of all Julys back to 1895 (Table 1). It was the wettest July since 1975 and second wettest in almost 50 years.

May Overview

Overview