2015: The 7th Warmest Year on Record for NYC

New York City experienced some noteworthy weather in 2015, especially swinging between the extremes of record cold and record warmth. In the end, though, the warmth won out. The city’s average annual temperature in Central Park was 56.7°F, which is 1.7°F above normal. That means 2015 tied 2010 as NYC’s 7th warmest year on record!

Starting off brutally cold, the winter of 2015 brought the city a number of extended arctic outbreaks and the term polar vortex seemed to be on everyone’s lips. The coldest day of the year came on February 20th when the temperature dropped to 2°F – a new record low for the date. Visible signs of the prolonged cold conditions were seen all over the city, from frozen fountains to ice filling both the Hudson and East Rivers. In the end, February 2015 ranked as our 3rd coldest February on record.

When the summer finally arrived, there were a number of very warm and humid days, but the first official heat wave – 3 consecutive days with readings of 90°F or higher – did not develop until August. The city typically sees 15 days per year with temperatures in the 90s, but 2015 produced a sweltering 20 – mostly in August and September. The hottest day did not arrive until September 8th when the mercury soared to 97°F in Central Park. After August 2015 became the city’s third warmest August on record, the heat just kept coming. September, November, and December were all record warm.

Precipitation was also erratic in NYC during 2015. While we had a number of heavy rain events, including some that broke daily rainfall records, such as the 2.10 inches that came down on January 18th, the city was mostly dry. Overall, we received 40.97 inches of rain in Central Park for the entire year. That is 8.97 inches below normal. This dearth of rain caused a moderate drought during the last few moths of the year. Snowfall, however, was abundant. March 2015 was our 6th snowiest March on record with 18.6 inches measured in Central Park. January and February also delivered above average snow totals with 16.9 inches and 13.6 inches, respectively. For the calendar year as a whole, the city accumulated 49.1 inches of snow, which is an astounding 23.3 inches above average.

Given that El Niño conditions developed and strengthened in 2015 and are forecast to last through the winter months of the new year, it will be interesting to see what type of weather events 2016 will bring.

2015Temps

Temperatures went from significantly below average to significantly above average in NYC during 2015. Credit: The Weather Gamut.

2015-rain

Rainfall was mostly below average in NYC during 2015. Credit: The Weather Gamut.

NYC Monthly Summary: December 2015

It was down right balmy in New York City this December! With an average temperature of 50.8°F in Central Park, which is a staggering 13.3°F above average, it was the city’s warmest December on record. The previous record of 44.1°F was set in 2001.

Overall, we had thirty out of thirty-one days with high temperatures above average. Five of those days tied or broke daily high temperature records, including Christmas Eve when the mercury soared to a spring-like 72°F in Central Park. Overnight lows were also above average throughout the month. In fact, this was the first December on record that overnight temperatures did not fall below freezing at least once.

While a few warm days in December is not that uncommon, this extended pattern of sustained warmth was very unusual. Driven primarily by El Niño, a persistent ridge in the jet stream over the eastern US allowed warm southern air to flow further north than it normally would at this time of year.

Given this unseasonable warmth, it is not surprising that only a trace of snow was measured in Central Park this December. On average, NYC usually receives 4.8 inches of snow for the month.  Rain, on the other hand, was plentiful.  In fact, December marked the first time since June that we saw above average rainfall. In all, the city received 4.72 inches of rain, which is 0.72 inches above normal. The majority of this total fell during two separate heavy rain events, which seem to be getting more common. Nonetheless, according to the latest report (12/29) from the US Drought Monitor, the city remains in a moderate drought.

DecTemps

Credit: The Weather Gamut

DecRainfall

Credit: The Weather Gamut

Warmest Christmas on Record for NYC

It was not a White Christmas in New York City this year, but it was still one to remember as temperatures soared into the record books!

On Christmas Eve, the temperature in Central Park reached a spring-like 72°F. That is a staggering 32°F above average and shattered the old record of 63°F set in 1996. On Christmas Day, the mercury climbed to 66°F surpassing the previous record of 64°F from 1982. The city’s normal high for this time of year is 40°F and the normal low is 29°F.

The primary driver of this unseasonable warmth is El Niño. It has produced a fairly persistent ridge in the jet stream over the eastern part of the country lately that is allowing warm air from the south to flow further north than it normally would in winter.

Talking with both locals and visitors, reactions to this record warmth has been mixed. While some enjoyed being able to walk around without a coat, others said they missed the traditional chill that is associated with the Holiday Season in New York.

Record Warm Christmas Eve 2015, NYC. Photo Credit: Melissa Fleming

Holiday decorations felt out of season this Christmas Eve as temperatures soared to record highs in NYC. Photo Credit: Melissa Fleming

Warmest November and Warmest Autumn on Record for Planet Earth

Our global temperature continued its seemingly unending upward trend last month with November 2015 marking not only the warmest November on record, but also closing out the warmest meteorological autumn ever recorded for the entire planet.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 56.95°F, which is a whopping 1.75°F above the 20th century average. It surpassed the previous record set in 2013 by 0.27°F and was the second highest departure from average for any month ever recorded. The highest departure (1.79°F) occurred last month. November also marked the seventh consecutive month this year to break a monthly temperature record.

The three-month period of September, October, and November – known as the meteorological autumn in the northern hemisphere – was also a record breaker. The planet’s temperature for the season was 58.83°F, which is 1.73°F above average. That is also 0.38°F above the previous record that was set just last year.

While heat dominated most of the planet this autumn, some places were particularly warm, including North America. Here in the contiguous US, with a seasonal temperature of 56.8°F, which is 3.3°F above average, it was our warmest autumn on record. The previous record was set in 1962.

Although strong El Niño conditions –a periodic natural climate phenomenon – helped fuel this record warmth, it does not tell the whole story. The long-term trend of human-caused climate change was also a key factor. NOAA reports that fourteen of the fifteen warmest years on record have occurred since 2000 and they were not all El Niño years.

Year to date, the first eleven months of 2015 were the warmest of any year on record. At this point, December’s global temperature will have to be significantly below average to prevent 2015 from surpassing 2014 as the warmest year ever recorded on this planet. Global temperature records date back to 1880.

Credit: NOAA

Record Warm Autumn (Sept, Oct, Nov) for the planet. Credit: NOAA

Record-Breaking December Warmth for NYC

The official start of winter is a week away, but you would never know it in the eastern United States. Temperatures have been so warm that is feels like spring and heat records across the region are being shattered.

Here in New York City, daily high temperature records have been tied or broken for three consecutive days. On Sunday, the temperature reached 67°F in Central Park, breaking the old record of 64°F from 1923. Monday’s high of 67°F tied the record from 1881 and today, in the early morning hours, the mercury climbed to 68°F surpassing the previous record of 67°F from 2008. Evening temperatures have also been exceptionally warm. In fact, the overnight lows have been warmer than the average highs for the past few days. Sunday even posted a new record maximum low of 55°F. The city’s normal high for this time of year is 43°F and the normal low is 32°F.

The primary driver of this unseasonable warmth is El Niño. It has produced a large ridge in the jet stream over the eastern part of the country that is allowing warm air from the south to flow further north than it normally would at this time of year.

To date, according to the NWS, the city is running 12.1°F above average for the month. While this warm weather can be easy to get used to, it makes all the holiday decorations around town feel out of season. So, I guess we can say that El Niño is the Grinch that stole Christmas this year.

WarmDec

NYC is experiencing above average high and low temperatures this December. Credit: The Weather Gamut

Record Warm Autumn for NYC

The autumn of 2015 brought exceptionally warm conditions to New York City. According to the NWS Central Park climatological station, it tied 1931 for the all time warmest meteorological Fall (September, October, November) on record.

Overall, the city’s average temperature for the past three months was 61.8°F. That is 4.2°F above average. Looking back, every month of the season was above its long-term norm. In fact, September and November each broke their monthly temperature records.

While winter is coming and overall temperatures are dropping, they are warmer than average for this time of year. The main reasons for this are likely a combination of global warming and a strong El Niño, which tends to push the jet stream further north than normal.  Weather records for Central Park date back to 1869.

Autumn2015

Source: NWS

NYC Monthly Summary: November 2015

November felt down right balmy in New York City this year. With an average temperature of 52.8°F in Central Park, which is a staggering 5.1°F above average, it was the city’s warmest November on record! The previous record was set in 2001.

Overall, we had twenty-two out of thirty days with high temperatures above average. Five of those days posted readings in the 70s, including November 6th when the mercury soared to 74°F in Central Park, tying the record high for the date that was set in 1948. Nine days saw temperatures in the 60s. Overnight lows were also mostly above normal. Historically, our average temperature for the month is 47.7°F.

November’s unseasonable warmth was produced by a fairly persistent ridge in the jet stream over the eastern US. It allowed warm air from the south to flow further north than it normally would at this time of year.

In terms of precipitation, November was unusually dry and marked the fifth consecutive month that NYC received below average rainfall.  In all, we received 2.01 inches of rain, which is 2.01 inches below normal. More than half of this modest total fell on a single day. The city, according to the latest report (11/24) from the US Drought Monitor, remains in a moderate drought.

Nov_Temps

Nov_Rain

October 2015: Warmest October on Record for Planet Earth

Our global temperature continued its upward trend last month with October 2015 marking the warmest October ever recorded for the entire planet.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 58.86°F, which is a whopping 1.76°F above the 20th century average. It surpassed the previous record set in October 2014 by 0.36°F. It also marked the highest departure from average for any month on record, eclipsing the previous record set just last month. October was also the sixth consecutive month this year to break a monthly temperature record.

Although strong El Niño conditions – a natural climate phenomena that boosts oceanic and atmospheric temperatures – helped fuel October’s record warmth, it does not tell the whole story. The long-term trend of human-caused climate change was also a key factor. NOAA reports that fourteen of the fifteen warmest years on record have occurred since 2000 and they were not all El Niño years.

While heat dominated most of the planet last month, some places were particularly warm, including most of Australia and North America. Here in the contiguous United States, with an average temperature of 57.4°F, it was our fourth warmest October on record and the warmest since 1963.

Year to date, the first ten months of 2015 were the warmest of any year on record. This strengthens the likelihood that 2015 will surpass 2014 as the Earth’s warmest year ever recorded. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

September 2015: Warmest September on Record for Planet Earth

Our global temperature continued its upward trend last month with September 2015 marking the warmest September ever recorded for the entire planet.

According to a report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 60.62°F, which is 1.62°F above the 20th century average. It surpassed the previous record set just last year by 0.19°F and marked the highest departure from average for any month on record. September was also the fifth consecutive month this year to break a monthly temperature record.

Although strong El Niño conditions – a natural climate phenomena that boosts oceanic and atmospheric temperatures – helped fuel September’s record warmth, it does not tell the whole story. The long-term trend of human-caused climate change was also a key factor. NOAA reports that fourteen of the fifteen warmest years on record have occurred since 2000 and they were not all El Niño years. This September, the globally averaged sea surface temperature was 1.46°F above the 20th century average of 61.1°F.  That is the highest temperature departure for any September on record. And, as NOAA points out, “This departure from average is also 0.45°F higher than the global ocean temperature for September 1997, when the last strong El Niño occurred.”

While heat dominated most of the planet last month, some places were particularly warm, including most of North America. Here in the contiguous United States, it was our second warmest September on record. With a monthly temperature of 68.5°F, which is 3.7°F above the long-term norm, only September 1998 was warmer. In fact, most of the lower forty-eight states experienced exceptionally warm conditions and nine  – Connecticut, Colorado, Maine, Michigan, Minnesota, New Mexico, Rhode Island, Utah, and Wisconsin – were record warm.

Year to date, the first nine months of 2015 were the warmest of any year on record. That puts 2015 well on track to becoming Earth’s warmest year ever recorded. Global temperature records date back to 1880.

Credit: NOAA/NCEI

Credit: NOAA/NCEI

Historic Flooding in South Carolina

Relentless rain unleashed catastrophic flooding across South Carolina this past weekend. Officials say it was one of the worst disasters in the state’s history.

According to the NWS, an estimated 5.8 trillion gallons of water fell in the Palmetto state in just four days with some communities receiving more than 20 inches of rain. This storm total exceeds that of any tropical cyclone on record that has impacted South Carolina.

Receiving this massive amount of precipitation in such a short period of time overwhelmed rivers and streams, and even caused a number of dams to breach. The floodwaters inundated homes, businesses, and shut down major roadways, including parts of Interstate-95. Local officials say the storm also caused water mains to break, leaving more than 40,000 people without drinkable water. To date, seventeen weather-related deaths have been reported across the state.

This type of rainfall is considered a one in thousand year event in South Carolina. That does not mean it can only happen once every thousand years. It refers to the recurrence interval – a statistical calculation that means an event has a one in one thousand chance (0.1%) of happening in any given year in a given location.

The cause of this widespread and destructive flooding was the unique convergence of three different weather systems that essentially set up an atmospheric river – a fire hose of moisture – aimed directly at South Carolina. The first was Hurricane Joaquin, which sat over the Bahamas for days and pumped huge amounts of moisture into the atmosphere. The second was an upper level low-pressure area over the southeastern US and Gulf of Mexico. It helped pull some of Joaquin’s moisture westward toward the US coastline. And lastly, there was a stalled frontal boundary along the coast. When the warm saturated air encountered the cooler air along the front, it was forced to rise and cool. Since cool air holds less moisture than warm air, the moisture was wrung out of the atmosphere in the form of intense rain over the same area for days.

Although the rain has now cleared, South Carolina is not out of the woods just yet. As swollen rivers make their way to the Atlantic, more flooding is expected in the state’s coastal low country.

Credit: NWS Columbia/NOAA

Credit: NOAA/NWS Columbia