Tag Archives: heat

Climate Indicator: Record Highs Outpacing Record Lows

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There are a variety of indicators that show our climate is changing, including increasing average temperatures, melting glaciers, and sea-level rise. Nevertheless, it is extreme events, such as record heat, that usally garner the most attention.

Around the globe, the number of record high temperatures are out-numbering record low temperatures. In the US, according to an analysis by the AP, record warm days have out-paced record cold days by a ratio of 2:1 since 1999. This is a clear sign of our climate is shifting to a “new normal”.

In a stable climate, record highs and lows would be more balanced, with the ratio being closer to 1:1.

While climate change is a global phenomenon, we can see it playing out at a local scale. Here in New York City, we still get the occasional cold snap in winter, but the record highs have been outpacing the record lows for decades.

Credit: Climate Central

July 2019: Earth’s Warmest Month on Record

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Our global temperature continued its upward trend last month with July 2019 marking not only the warmest July on record, but also the warmest month ever recorded for the entire planet. The previous record was set just three years ago in July 2016.

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 62.11°F. That is 1.71°F above the 20th-century average. Since July is the Earth’s warmest month of the year climatologically, the July 2019 global temperature is now the highest temperature for any month on record.

July 2019 also marked the 415th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below-average reading was December 1984. Furthermore, nine of the ten warmest Julys have occurred since 2005, with the last five years producing the five warmest Julys on record. July 1998 is the only year from the last century on the top ten list.

While heat dominated most of the planet this July, some places were particularly warm, including Europe as well as parts of Asia, Africa, and Australia. In the United States, Alaska posted its warmest month ever recorded. For the contiguous US, the month tied July 1917 as the 27th warmest July on record.

These soaring temperatures are largely attributed to the long-term trend of human-caused climate change. As greenhouse gases continue to spew into the atmosphere, global temperatures are expected to continue to rise.

Year to date, the first seven months of 2019 tied 2017 as the second warmest such period of any year on record. At this point, it is very likely that 2019 will finish among the top five warmest years on record. Global temperature records date back to 1880.

July 2019 was the warmest month ever recorded on this planet. Credit: NOAA

July 2019: Tenth Hottest July on Record for NYC

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July is usually the warmest month on the calendar for New York City, but this year it was especially hot. In fact, it tied July 1949 as the city’s tenth warmest July on record.

In all, it produced 26 days with above-average readings, including ten days in the 90s. Four of those days came during a heatwave in the middle of the month when the air temperature reached 95°F and the humidity made it feel well above 100°F.

Overnight lows were also mostly warmer than normal throughout the month. On July 20, the mercury only fell to 82°F, setting a new record warm low temperature for the date. In the end, the city’s mean temperature for the month was 79.6°F, which is 3.1°F above average.

It is important to note that four of the city’s ten warmest Julys on record have now occurred since 2010. The warmest was July 1999, when the average temperature for the month was 81.4°F.

This July was also above average in terms of precipitation. With several intense thunderstorms rolling through the area, a total of 5.77 inches of rain was measured in Central Park. The city, on average, gets 4.60 inches of rain for the month.

Credit: The Weather Gamut

First Heatwave of 2019 Brings Extreme Temperatures to NYC

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A heatwave gripped a large swath of the eastern United States this weekend. For many areas, the temperatures were extreme.

The threshold for what constitutes a heatwave varies by region, but here in the northeast, it is defined as three consecutive days with temperatures reaching 90°F or higher. In New York City, the official temperature in Central Park reached 91°F on Friday, and 95°F on both Saturday and Sunday. Overnight lows were also well above average. In fact, on Saturday, the temperature only cooled down to 82°F, tying the record warm low termperature for the date that was set in 2015.

When the humidity was factored in, it felt even hotter. The heat index ranged from 105°F-110°F.

The city’s airports, LGA and JFK, both in the borough of Queens, posted record high temperatures over the weekend, according to the National Weather Service. JFK hit 99°F on Saturday, breaking the previous record of 96°F that was set in 2013. On Sunday, LGA reached the century mark (100°F), tying the high-temperature record for the date at the site that was set in 1991.

The cause of this exceptional heat was two-fold. First, a large area of high pressure sitting over the central US was pumping hot air from the southwest toward the northeast. At the same time, a strong Bermuda High off the east coast was pumping warm, moist air from the Gulf of Mexico into the region. Together, they made it dangerously hot, which is why the NWS issued an excessive heat warning for the city. It is also why several outdoor events around the Big Apple were canceled, including the NYC Triathlon.

The hottest day ever recorded in New York City occurred on July 9, 1936, when the air temperature hit 106°F in the shade. The city’s normal high temperature this time of year is 84°F.

A Tale of Two Highs: The Science Behind the Excessive Heat in the Northeast

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Summer is the season for warm weather and even the occasional heatwave. But, the excessive heat that is gripping the eastern United States this weekend is exceptional. Its source is essentially a tale of highs – two areas of high pressure, that is.

The first is a Bermuda High. This is a large, semi-permanent, area of high pressure situated off the east coast. Spinning clockwise, it is strongest in the summer months and often steers hot, humid air from the Gulf of Mexico toward the northeast. It is usually the main cause of heatwaves in the region.

This current heatwave, however, is getting an extra boost from a second area of high pressure that is sitting over the central US. Also spinning clockwise, it is funneling hot air aloft from the southwest toward the northeast. Traveling eastward, this hot air must pass over the Appalachian Mountains, which run parallel to the eastern seaboard from Georgia to Maine. Following the topography downslope on the lee side of the mountains, the air compresses and warms even further. This is producing the exceptionally high air temperatures, such as the upper 90s and triple digits reported in cites across the region.

Combining this excessively hot air with the humidity being pumped into the area by the Bermuda High, the heat index or real feel temperatures are well above 100°F in many places.

This type of weather is more than just uncomfortable, it is dangerous. To avoid health complications, the American Red Cross recommends avoiding strenuous outdoor activity, drinking plenty of fluids, and cooling off in air-conditioned spaces when possible.

Credit: NOAA/NWS

Extreme Heat Can Pose a Danger to Your Health

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A heat emergency has been issued for New York City.  As temperatures soar, it is important to remember that intense heat can cause serious health problems.

According to the CDC, extreme heat – temperatures that are significantly hotter than the average local summertime high – is one of the leading causes of weather-related deaths in this country. Claiming hundreds of lives every year, excessive heat kills more people across the U.S. than hurricanes and tornadoes combined.

Extreme heat is deadly because it forces the human body beyond its capacity to cool itself. Linked to overheating and dehydration, heat-related illnesses can range in severity from mild to life-threatening.  Symptoms for each stage include:

Heat Cramps:  Painful muscle spasms in the legs and/or abdomen

Heat Exhaustion:  fatigue, weakness, clammy skin, and nausea

Heat Stroke:  rapid pulse, hot and dry skin, no sweating. This is a medical emergency

To beat the heat, the American Red Cross suggests:

  • Avoid strenuous activity
  • Dress lightly
  • Eat lightly
  • Drink plenty of water
  • Replenish salts and minerals lost through perspiration with sport-drinks
  • Limit caffeine and alcohol
  • Stay out of the sun
  • Cool off in an air-conditioned building, when possible

Credit: NWS/WRN

June 2019: Warmest June on Record for Planet Earth

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Our global temperature continued its upward trend last month with June 2019 marking the warmest June ever recorded on this 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 61.61°F. That is a staggering 1.71°F above the 20th-century average and 0.04°F above the previous record that was set in 2016.

June 2019 also marked the 414th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below-average reading was December 1984. Furthermore, nine of the ten warmest Junes have occurred since 2010. June 1998 is the only year from the last century on the top ten list and currently ranks eighth.

While heat dominated most of the planet this June, some places were particularly warm, including Europe, parts Russia and South America, as well as Alaska. In fact, Europe posted its warmest June on record and Alaska had its second warmest June since statewide record-keeping began there in 1925.

For the contiguous US as a whole, this June was close to average and ranked in the middle third of the national record. To put this disparity into context, consider that the United States constitutes less than 2% of the total surface of the Earth. This detail also highlights the fact that climate change is a complex global phenomenon that involves long-term trends more than the short-term weather conditions that are happening in any one part of the world.

Year to date, the first six months of 2019 tied with the first half of 2017 as the second warmest such period of any year on record. At this point, it is very likely that 2019 will finish among the top five warmest years on record. Global temperature records date back to 1880.

June 2019: Earth’s Warmest June on Record. Credit: NOAA

“Warming Stripes”: The Colors of Climate Change

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Sometimes a picture is worth a thousand words. That is the case with “Warming Stripes”, a creative visualization of climate data by Ed Hawkins, a scientist at the UK’s National Centre for Atmospheric Science.

Painting a picture of our changing climate, each stripe represents a single year from 1850 through the present. With an aesthetic similar to color field paintings by artists such as Barnett Newman or Mark Rothko, the images use only color to communicate meaning. Simplifying a complex issue for maximum impact with the general public, they avoid distracting details and focus on the big picture.

In “Warming Stripes for the Globe” (see below), it is plain to see the shift from blue (cooler) on the left to red (warmer) on the right. While there were a few warm years here and there in the past, the overall trend clearly shows temperatures are getting warmer. It is also important to note that the red has been getting darker (hotter) in recent years.

To see how the warming trend is playing out on a more regional or local level in different parts of the world, visit www.showyourstripes.info

“Warming Stripes for Globe, 1850-2018”. Credit: Ed Hawkins

First 90°F Day of the Year for NYC

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The heat is on in New York City! The temperature in Central Park soared to 91°F on Saturday, marking the city’s first 90°F day of the year.

While readings in the 90s are not uncommon for the Big Apple during the summer months, they typically premiere earlier in the season. On average, the city usually sees its first 90°F day by the end of May.

According to NWS records, the city’s earliest first 90°F day was April 7, 2010, and its latest was July 26, 1877.

For the season as a whole, NYC typically gets an average of 15 days with temperatures reaching 90°F or higher. By month, that usually breaks down as May (1), June (3), July (6), August (4), and September (1). That said, every year is different. The most 90°F days the city experienced was 37 during the sweltering summer of 2010.

Credit: Melissa Fleming

Summers are Getting Hotter in the US

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Summer is the warmest part of the year with high sun angles and long daylight hours. But, as our climate changes, the season is getting even hotter.

Across the contiguous United States, summer temperatures have increased an average of more than 2°F over the past fifty years, according to Climate Central, a non-profit science news organization. The western and southwestern parts of the country have seen the fastest seasonal increase, with places like Boise, ID, Las Vegas, NV, and McAllen, TX each warming more than 5°F since 1970.

Soaring temperatures can pose a risk to human health and cause energy costs to skyrocket as people try to beat the heat.  They can also lead to drought and threaten agricultural production.

Reducing global greenhouse gas emissions, which are causing the atmosphere to warm, can minimize many of these impacts. On a local level, adaptation measures are also important. In urban areas, which tend to heat up quickly, planting more trees can help keep neighborhoods cooler during the increasingly intense heat of the summer months.

Credit: Climate Central