Tag Archives: heat

NYC Monthly Summary: July 2015

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July is normally the warmest month on the calendar for New York City, and this year was no exception. Despite getting off to a relatively cool start, the month brought us five days with temperatures in the 90s. These hot days helped bring the city’s mean temperature for the month up to 78.8°F, which is 2.3°F above average.

While we had a few stretches of very warm and humid days, including some where the heat index reached  the triple digits, it is interesting to note that we did not technically have a single heat wave all month. In this part of the US, a heat wave is defined as three consecutive days with temperatures reaching 90°F or higher.

On the precipitation side of things, NYC was mostly dry. In all, we received 3.98 inches of rain in Central Park, which is 0.62 inches below average. Of this total, 1.95 inches fell in a single day as a cold front moved through the area triggering thunderstorms and intense downpours.  July is typically the wettest month of the year in the Big Apple.

July_Temp

July_rain

Exploring the Urban Heat Island Effect Within City Limits

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During the summer months in New York City, you often hear people talking about plans to escape the city’s heat with trips to the beach or mountains. This is because NYC, like most large cities, is an urban heat island. With miles of paved surfaces that absorb heat, it is generally warmer than surrounding rural areas.

Within city limits, the temperature difference between an asphalt covered street and a nearby park lawn can demonstrate this phenomenon on a smaller scale. Below are some photos of measurements we made around midtown Manhattan at 2:30 PM this afternoon when the air temperature was 95°F.

On the street, the temperature was 122°F in the sun and 101°F in the shade. On the park lawn, only a few feet away, the temperature in the sun was 99°F and a relatively cool 85°F in the shade.  Hands down, the best place to beat the heat – even in the city – is on a grassy surface in the shade.  Stay cool!

Comparing temperatures of surfaces in sun and the shade around midtown Manhattan on July 29th.

Comparing temperatures of surfaces in the sun and the shade around midtown Manhattan on July 29th when the air temperature was 95°F .  Credit: The Weather Gamut.

June 2015: Warmest June on Record for Planet Earth

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Our global temperature continued its upward trend last month with June 2015 marking the warmest June 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 61.48°F, which is 1.58°F above the 20th century average. It surpassed the previous record set last year by 0.22°F and marked the fourth highest monthly departure from average for any month on record.

June was also the third month this year to break its monthly temperature record, joining  March and May. The other months of 2015 each posted readings that ranked in their top five warmest.

For the oceans, the globally averaged sea surface temperature for the month was 1.33°F above the 20th century average of 61.5°F.  That is the warmest reading on record for any June, eclipsing the previous record set just last year. It also tied with September 2014 as the highest monthly departure from average for any month.

While moderate El Niño conditions  – a natural climate pattern that boosts oceanic and atmospheric temperatures – played a role in June’s record heat, 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 six months of 2015 were the warmest of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

May 2015: Warmest May on Record for Planet Earth

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Our global temperature continued to rise last month. In fact, May 2015 was the warmest May ever recorded for the entire planet.

According to a report by NOAA’s National Climatic Data Center, Earth’s combined average temperature for the month – over both land and sea surfaces – was 60.17°F. That is 1.57°F above the 20th century average. The previous record was set last year. NOAA also said the May 2015 global temperature “ties with February 1998 as the fourth highest monthly departure from average for any month on record. The two highest monthly departures from average occurred earlier this year in February and March.”

While heat dominated most of the planet last month, some places were particularly warm. Here in the US, five states – Alaska, Connecticut, Massachusetts, New Hampshire, and Rhode Island – each had a record warm May.

Rising ocean temperatures, according to NOAA, helped fuel the month’s record warmth. The global sea surface temperature for May was 1.30°F above the 20th century average of 61.3°F.  That is the warmest on record for any May surpassing the previous record set just last year. It should be noted, however, that moderate El Niño conditions were present across the central and eastern Pacific Ocean last month.

Year to date, the first five months of 2015 were the warmest of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

NYC Monthly Summary: May 2015

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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

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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.

Winter 2014-15: Warmest on Record for Planet Earth

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Looking back at the winter of 2014-2015, conditions here in the northeastern United States were exceptionally cold and snowy. Globally, however, it was a record warm season!

According to a recent report from NOAA’s National Climatic Data Center, the meteorological winter of 2015 (December, January, and February) was the warmest winter ever recorded on this planet. Earth’s combined average temperature for the season – over both land and sea surfaces – was 55.22°F. That is 1.42°F above the 20th century average.  It surpassed the previous record set in the winter of 2006-07 by 0.07°F.

Rising ocean temperatures, according to NOAA, helped fuel the season’s record warmth. Between December and February, the average global ocean surface temperature was 61.67°F, which is 0.97°F above average and the third highest ever recorded for the three month period.

In the contiguous United States, this past winter was the 19th warmest on record with an average temperature of 34.3°F. That is 2.1°F. above the 20th century average. NOAA says the record warmth in the West outweighed the cold in the East.

While the Earth’s atmosphere and oceans are warming overall, this winter’s temperature anomalies (both above and below average) highlight the fact that climate change is a complex global phenomenon that involves much more than what is happening in our own backyards.

Year to date, 2015 is off to a record warm start. Global temperature records date back to 1880.

Image Credit: NOAA/NCDC

Temperature Anomalies for Dec 2014 through Feb 2015. Image Credit: NOAA/NCDC

Image Credit: NOAA/NCDC

One of the only cold spots this winter was the northeastern US. Image Credit: NOAA/NCDC

Second Warmest February on Record for Planet Earth

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Temperatures around the globe soared last month. In fact, February 2015 was the second warmest February ever recorded for the entire planet.

According to a report released by NOAA’s National Climatic Data Center, Earth’s combined average temperature for the month – over both land and sea surfaces – was 55.38°F. That is 1.48°F above the 20th century average. The warmest February on record occurred in 1998, when the temperature was 1.55°F above average and El Niño conditions were in place.

For those living in the northeastern United States, this news may come as a bit of surprise. Many cities in the region experienced a frigid February this year. Here in New York City, it was the 3rd coldest on record. But, this difference in regional and global conditions highlights the fact that climate change is a complex phenomenon that involves much more than what is happening in our own backyards.

Global temperature records date back to 1880.

Global temperature departures from average for February 2015. Image Credit: NOAA/NCDC

Temperature departures from average for February 2015. Image Credit: NOAA/NCDC

Climate Change Projections for NYC

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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

Second-Warmest January on Record for Planet Earth

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Last year, 2014, was the hottest year ever recorded on this planet. January 2015 continued the trend, ranking as the second-warmest January on record.

According to a report released by NOAA’s National Climatic Data Center, Earth’s combined average temperature for the month – over both land and sea surfaces – was 54.99°F. That is 1.39°F above the 20th century average. The warmest January on record  occurred in 2007, when the temperature was 1.55°F above the long-term norm.

While heat dominated most of the planet last month, some places were particularly warm. China had its warmest January on record since 1961. In the contiguous US, seven western states – California, Idaho, Nevada, Oregon, Utah, Washington, and Wyoming – each experienced a January rated in their top ten warmest.

Global climate records go back to 1880.

Image Credit: NOAA/NCDC

Image Credit: NOAA/NCDC