The List: The Hottest Months in NJ Since Records Began

Colleen O'Dea | August 14, 2019 | The List
If you’ve been around since the year 2000, you have lived through most of the hottest months on record in New Jersey

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Complaints about this summer’s heat and humidity have been justified: Last month was the fifth hottest July on record in New Jersey.

The New Jersey State Climatologist has ranked the five hottest — and coldest — of all months since 1895, when temperature records began to be kept. July’s high temperatures brought to 38 the number of months in the rankings for the top-five-hottest that have occurred since 2000. That accounts for two-thirds of the total number since 1895. A graphic of temperature extremes from the Office of the New Jersey State Climatologist at Rutgers University illustrates the pattern.

None of the five coldest months on record have been this century, so far. The most recent coldest month was December 1989, which ranked as the coldest since 1895.

The statistics New Jersey State Climatologist David Robinson collects and disseminates are important to discussions of climate change, which Robinson has said is happening and is influenced by the actions taken by humans.

“You’d have to throw physics out the window if you believe that you can keep putting more carbon dioxide in the atmosphere without having an effect,” Robinson was quoted as telling the New Jersey Conservation Foundation in a column published on the organization’s website last February. “We’re seeing changes, and the connections are undeniable.”

Murphy administration’s approach to climate change

New Jersey has taken some steps to tackle its contributions to climate change, although critics argue the Murphy administration is not doing enough.

Last month Gov. Phil Murphy signed into law a bill requiring the state to do a better job of monitoring and reporting on greenhouse-gas emissions and issue within the next year a report on additional steps to curb carbon pollution. It is meant to bolster a 2007 law requiring the state to reduce carbon pollution by 80 percent below 2006 levels by the year 2050, a target some say the state is unlikely to meet.

And the state’s new draft energy master plan seeks to electrify the transportation and building sectors and shift away from gas and other fossil fuels. But some environmentalists want Murphy to issue a moratorium on all new fossil-fuel projects and say that without such a ban, New Jersey will fall short of meeting its carbon-reduction target.

A recent report from the Union of Concerned Scientists states that if climate change continues unchecked, New Jersey will see 24 days with a heat index of more than 100 degrees Fahrenheit each year by 2050 and 49 such days by the end of the century. Historically, the state has about three days a year, on average, with a 100-degree F heat index.

Robinson’s recap of last month’s weather states that the average statewide temperature was 77.9 degrees F, 3.3 degrees higher than the temperature mean for the period from 1981 to 2010. Three years are tied for the record high of 78.4 degrees F: 2011, 1999 and 1955.

Temperatures in South Jersey

In South Jersey, the average temperature last month was 78.9 degrees F, ranking it as sixth warmest July there ever, while in north Jersey, the 76.4-degree F average ranked the month as fourth warmest in that half of the state, tied with 2013.

The average temperature at night — 67.4 degrees F — was the second warmest for July on record, tied with 2011. Robinson attributed that to the excessive humidity that plagued New Jersey throughout most of the month, saying “a moist atmosphere inhibits the loss of the previous day’s heat during the overnight period.”

Overall, Robinson’s report on July temperatures was sobering: Eleven of New Jersey’s 20 warmest Julys since 1985 have occurred in the last 18 years.

It’s not just recent summer months that have been among the hottest in state history, but all the months. And the number of top-five-hottest months so far this decade is more than double the number counted from 2000 to 2009, with 26 top-fives in 2010-2018 compared with 12 in 2000-2009.

Here are the rankings for the five hottest of every month this century in New Jersey:

December — 5: The five hottest Decembers on record in New Jersey have all occurred since 2000. The hottest was in 2015, second-hottest in 2016, third-hottest in 2001, fourth-hottest in 2012 and fifth-hottest in 2011.

February — 4: February 2017 was the hottest, 2018 ranked second, 2012 ranked fourth and 2002 ranked fifth-hottest.

May — 4: May 2015 was the hottest May on record, with the second-hottest in 2004, fourth-hottest in 2018 and fifth-hottest in 2012.

August — 4: The hottest August on record was in 2016, second-hottest in 2018, third-hottest in 2005 and fourth-hottest in 2002.

November — 4: November 2015 was the hottest on record, second-hottest in 2006, third-hottest in 2009 and fourth-hottest in 2011.

September — 4: The second-hottest September occurred in 2013, the third in 2018, the fourth in 2005 and the fifth in 2016.

April — 3: The hottest April on record occurred in 2017, the second in 2010 and the fourth was this year.

July — 3: July 2011 was the hottest, 2010 ranked second and last month ranked fifth hottest on record.

October — 2: The hottest October occurred in 2007 and the second-hottest was in 2017.

June — 2: The hottest June occurred in 2010 and the third-hottest was in 2008.

March — 2: March 2012 was the hottest on record and the fourth-hottest occurred in 2016.

January — 1: January is the only month without a record this decade. The fourth-hottest January occurred in 2006.