NYC Monthly Summary: June 2015

June 2015 felt a bit like a weather rollercoaster in New York City. We had highs that ranged from an unseasonably cool 55°F to our first 90-degree day of the year.  In the end, however, the cold and warmth averaged each other out. The city’s mean temperature for the month was 71.2°F, which is only 0.2°F below normal.

On the precipitation side of things, the city had 14 days with measurable rainfall.  In all, we received 4.79 inches of rain, which is 0.38 inches above normal. Of this total, 1.41 inches fell in a heavy rain event during the last weekend of the month. June marked the first time since March that the city had above average monthly rainfall.

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NYC Monthly Summary: May 2015

May was unusually warm and dry in New York City this year.

With 26 out of 31 days posting above average highs, including 18 days with readings in the 80s, May felt more like summer than spring. Overnight lows were also well above average throughout most of the month. All together, the city’s mean temperature for the month was 68.5°F, which is 6.1°F above average.  That makes May 2015 the city’s 3rd warmest May on record.

In terms of precipitation, May was exceptionally dry. Coming on the heels of a parched April, the city, according to the latest report (5/28) from the US Drought Monitor, is currently in a state of moderate drought. All told, the city received a mere 1.86 inches of rain in Central Park. Of this meager total, 1.46 inches fell in a single day – the last day of the month – and caused localized flash floods. May, on average, typically brings NYC 4.19 inches of rain.

Graph Credit: The Weather Gamut

Graph Credit: The Weather Gamut

Graph Credit: The Weather Gamut

Graph Credit: The Weather Gamut

An Early Taste of Summer for NYC

The official start of summer is more than a month away, but temperatures have been soaring in New York City!

A large ridge in the jet stream has ushered unseasonably warm air into the region. In fact, eight of the last twelve days have seen temperatures reach well into the 80s. Today, the mercury soared to 86°F in Central Park, making it the warmest day of the year to date. Our normal high for this time of year is 70°F.

While the pre-season warmth can be easy to acclimate to, especially after a cold and snowy winter, these summer-like conditions are not expected to last much longer. A cold front is forecast to move through the region late tonight sending temperatures back to more seasonable levels.

NYC Monthly Summary: April 2015

Transitioning to spring, April 2015 felt like a weather rollercoaster in New York City. We had highs that ranged from a chilly 43°F to a balmy 80°F.  In the end, though, the warmth won out. The city’s mean temperature for the month was 54.3°F, which is 1.3°F above normal. That makes April the first month since December to produce an above average temperature in the Big Apple.

In terms of precipitation, April’s famous showers were scarce this year. The city received a mere 2.08 inches of rain in Central Park. Of this meager total, 1.37 inches fell in a single day. On average, NYC typically gets 4.5 inches of rain during the month of April.

Graph Credit: The Weather Gamut

Graph Credit: The Weather Gamut

Spring has Arrived in NYC

After a cold and snowy winter, birds are chirping and flowers are starting to bloom in New York City. More than three weeks after the vernal equinox, spring has finally sprung!

With a high temperature of 72°F in Central Park, today was the warmest day the city has seen all year.  It has not been this warm in the Big Apple since October. Our normal high for this time of year is 61°F.

Spring Flowers in NYC Garden

Spring Flowers in NYC Garden.  Credit: The Weather Gamut

Similar Weather for Easter and Christmas in NYC

Easter and Christmas are major holidays associated with the beginning of two different seasons – spring and winter, respectively. Nonetheless, the weather conditions for their most recent occurrences in New York City were oddly similar.

The high temperature in Central Park yesterday, Easter Sunday, was 61°F and the low was 42°F.  Back on Christmas Day, December 25th, the high was 62°F and the low was 44°F, tying the record for the city’s third warmest Christmas. Conditions this Easter were only slightly above average for the date.

The warmest Easter on record for NYC, according to the local National Weather Service office, was in 1976 when the high temperature reached 96°F. The coldest was in 1940 when the high was only 31°F.

NYC Monthly Summary: March 2015

March 2015 was a bit of a weather rollercoaster in New York City. We had highs ranging from a chilly 27°F to a relatively balmy 62°F. In the end though, with 23 out of 31 days posting below average readings, the cold won out. The extended cold snaps helped lower the city’s mean temperature for the month to 38.1°F, which is 4.4°F below normal. That makes March 2015 the coldest March the city has seen in 31 years.

In terms of precipitation, March 2015 was unusually snowy. In fact, according to the National Weather Service, it was NYC’s 6th snowiest March on record. The city measured 18.6 inches of snow in Central Park, which is a staggering 14.7 inches above average. We even had snow falling on the first day of spring.

Rainfall was also abundant. The city received 4.72 inches, which is 0.36 inches above average for the month.

Credit: The Weather Gamut.

Credit: The Weather Gamut.

NYC Seasonal Summary: Winter 2014-15

For the second year in a row, New York City had an unusually cold and snowy winter. While last year saw the term polar vortex go viral, this winter was actually colder in the Big Apple.

The city’s average temperature for this past meteorological winter (December, January, and February) was 31.4°F. That is 3.7°F below normal and 1.6°F below last winter’s average. This winter,  December posted an above average reading, but both January and February were significantly colder than normal.  In fact, February 2015 was the city’s 3rd coldest February on record.

In terms of snowfall, every month this winter, with the exception of December, was an overachiever. January brought the city 15.3 inches of snow, February produced 11.9 inches, and March delivered a whopping 18.6 inches. Even with a hefty grand total of 46.8 inches of snow in Central Park, this winter fell short of last year’s impressive 57.4 inches.  On average, NYC typically gets 25.1 inches for the entire winter season.

NYC Monthly Summary: February 2015

February was frigid in New York City this year! With an average monthly temperature of 23.9°F, it was the city’s 3rd coldest February on record.

We experienced several arctic outbreaks that caused fountains to freeze and ice to form on both the Hudson and East Rivers. Overall, we had 15 out of 28 days where our high temperature did not get above freezing. We also had 7 days where our low temperature dropped into the single digits, including February 20th when the mercury plummeted to 2°F in Central Park, marking a new record low for the date. Our normal high for the month is 42°F and our normal low is 29°F.

These relentlessly cold conditions were produced by an almost continuous deep dip in the jet stream that allowed arctic air to dive south into our region. Some scientists suggest there may be a connection between these extended periods of extreme cold and climate change. They say as the Arctic warms, the jet stream slows down creating a wavier configuration that allows weather systems to stay in place longer.

In terms of precipitation, February is usually a snowy month in the Big Apple and this year was no exception. The city had 11.9 inches accumulate in Central Park, which is 2.7 inches above average. The month did not bring us a single blockbuster snow event, but rather a string of small storms. Rainfall, on the other hand, was lacking.  The city only received 2.04 inches, which is 1.05 inches below normal for the month.

Credit: The Weather Gamut

Credit: The Weather Gamut

Climate Change Projections for NYC

Climate Change is a global problem with impacts that vary from place to place. In New York City, they include hotter temperatures, heavier precipitation events, rising sea levels, and increased flooding. Each one of these local challenges was spelled out in detail by the latest report from the New York City Panel on Climate Change (NPCC).

According to the report, temperatures are expected to increase between 4.1°F and 5.7°F by the 2050s and between 5.3°F and 8.8°F by the 2080s. The frequency of heat waves is forecast to jump from the current average of 2 per year to 6 by the end of century.

Annual precipitation is projected to increase 4% to 11% by the 2050s and 5% to 13% by the 2080s. The report also calls for the number of days with extreme precipitation – heavy rain and snow – to increase 1.5 times by the 2080s.

Local sea levels are expected to rise between 11 inches and 21 inches by the 2050s, 18 inches to 39 inches by the 2080s, and up to six feet by 2100. As an archipelago, NYC is especially vulnerable to sea level rise. Higher sea levels give storm surges a higher starting point, allowing floodwaters to reach further inland. That means Sandy-like flooding will become more probable in the future even with a less powerful storm. In fact, if the high end projections of sea level rise come to fruition, the current 1-in-100 year flood event could happen roughly every 8 years.  The city’s flood zone is expected to double in size by 2100.

These changes are not only significant for their quantities, but also for the rate at which they are forecast to occur.  To put them into perspective, compare them to the recent past. Between 1900 and 2013, the city’s annual temperature increased 3.4°F, mean annual precipitation increased 8 inches, and local sea levels rose by 1.1 feet.

Taking steps to both adapt to and mitigate climate change, NYC has started building flood protection systems and has pledged to reduce its greenhouse gas emissions 80% from 2005 levels by 2050.

Formed in 2008, the NPCC assesses the latest climate science and analyzes the specific impacts facing NYC.  It issues a report every 3 years.

Credit: NPCC 2015 Report

NYC faces an increasing risk of floods due to sea level rise and climate change.                          Credit: NPCC 2015 Report