Tag Archives: stats

NYC Monthly Summary: October 2015

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October was a weather roller-coaster in New York City this year. We had highs that ranged from a relatively balmy 78°F to a chilly 50°F.  In the end though, the warmth won out. The city’s mean temperature for the month was 58°F, which is 1.1°F above average.

On the precipitation side of things, October was mostly dry and marked the city’s fourth consecutive month with below average rainfall. In all, we received 3.91 inches of rain in Central Park, which is 0.49 inches below normal. Of this total, 1.44 inches fell in a single heavy rain event during the last week of the month. Despite this soaker, the city remains in a moderate drought according to the latest report (released on 10/29) from the US Drought Monitor.

October was a temperature roller-coaster in NYC. Credit: The Weather Gamut

October was a temperature roller-coaster in NYC.  Credit: The Weather Gamut

September 2015: Warmest September on Record for Planet Earth

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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

NYC Monthly Summary: September 2015

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Summer-like weather extended well into September in New York City this year. With an average temperature of 74.6°F, it was the city’s warmest September on record! It surpassed the previous record set in 1961 by 1.1°F.

Overall, we had twenty-seven out of thirty days with high temperatures above average. Six of those days posted readings in the 90s, including September 8th when the mercury soared to 97°F in Central Park, marking a new record high for the date. Typically, we only see one 90-degree day during September in NYC. Historically, our average temperature for the month is 68°F.

This extended period of warmth was produced by a 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, September was unusually dry and marked the third consecutive month that NYC received below average rainfall.  In all, we received 3.28 inches of rain, which is one inch below normal. The vast majority of this modest total fell on two separate days in the form of intense downpours. In fact, September 10th set a new daily rainfall record with 1.58 inches measured in Central Park. Nonetheless, despite these soakers, NYC remains in a moderate drought according the latest report (9/29) from the US Drought Monitor.

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Celebrating Fourth Blogiversary

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Four years ago today, I started writing this blog and it has been both an amazing and rewarding journey.

Initially begun as a way to deepen and share my knowledge about weather and climate change, this blog has allowed me to expand on my interests and concerns in ways that I never thought possible four years ago. This past year, I developed a selection of slide presentations about climate change and have spoken at a variety of venues, including a national conference. It has also introduced me to many wonderful people working in this fascinating field. Looking ahead, I am hoping to add some video content to the blog over the next few months. So, stay tuned!

As always, thank you for reading!

4_Blogiversary

Image Credit: Maria Elena

NYC Monthly Summary: August 2015

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It was hot in New York City this August. Everyday produced a high temperature above 80°F and eight days saw the mercury climb to 90°F or higher, which is twice the average number for August. Additionally, the month brought the city its first official heat wave in two years. With overnight lows also running mostly above normal, the city’s mean temperature for the month was 79°F, which is 3.8°F above average. This makes August 2015 the city’s 3rd warmest August on record.

On the precipitation side of things, August was very dry in the Big Apple. All told, the city received a mere 2.35 inches of rain in Central Park, which is 2.09 inches below average. On the latest report (8/25) from the US Drought Monitor, the NYC area is listed as “abnormally dry”.

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July 2015: Warmest Month on Record for Planet Earth

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Our global temperature continued its upward trend last month with July 2015 marking not only the warmest July on record, but the warmest month 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 61.86°F, which is 1.46°F above the 20th century average. It surpassed the previous record set in 1998, which was also an El Niño year, by 0.14°F.

July 2015 also marked the 39th consecutive July that our global temperature was above its long-term norm. NOAA says that July – which is climatologically the planet’s warmest month – has been getting hotter over the years. Records show that the temperature for the month is currently increasing at an average rate of 1.17°F per century.

For the oceans, the globally averaged sea surface temperature for the month was 1.35°F above the 20th century average of 61.5°F.  That is the highest departure on record for any month. According to NOAA, the ten highest monthly departures from average for ocean temperatures have all occurred since April 2014.

While heat dominated most of the planet in July, some places were particularly warm. Heat waves in Europe pushed temperatures to record levels across the region. In fact, it was the warmest July on record for both Austria and Spain. Here in the contiguous US, temperatures were slightly warmer than average, but no state set a new record high. This difference highlights 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, the first seven months of 2015 were the warmest of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

The Hottest Days of Summer Vary By Region

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For the continental U.S. as a whole, the hottest part of summer arrives in mid to late July. On the regional level, however, there are significant differences in the timing of the hottest part of the season.

Based on historical averages, NOAA’s National Centers for Environmental Information (NCEI) produced a map showing how the warmest days of summer vary across the country. The desert southwest, for example, is an early bloomer in terms of heat.  It’s warmest days typically arrive in June.  By early July, the North American Monsoon – a seasonal shift in wind direction – kicks in and helps keep the region relatively cool and rainy through September.

In parts of the south central states, a persistent area of high pressure typically builds over the region in August. This limits cloud formation and dries out the soil, which helps to send temperatures skyrocketing.

On the other far end of the spectrum, temperatures along the west coast do not peak until September. This lag is the result of hot air rising over interior deserts and cool Pacific air flowing in-land.  By September, this upper-level wind pattern usually weakens and allows warm air to flow toward the coast.

While the NCEI map is derived from long-term climate averages, it is important to note that short-term variability can cause the date of peak temperatures to vary in any given year.

summer-heat

Credit: NOAA/NCEI

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.

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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

NYC Monthly Summary: June 2015

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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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