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Seeing Climate through Degree Days

climate CDD HDD heat cold
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#1
IbrChris

Posted 04 January 2015 - 02:19 AM

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Looking at climate through the lens of degree days (base 65 F US, 64 F/18 C INTL)

Cooling degree days occur any time the mean temperature of the day is more than 65 F/18C.
Heating degree days occur any time the mean temperature of the day is less than 65 F/18C.

 

A good way to measure climates is to look at the mean HDDs and CDDs during a typical year. We can also sum the two to get an idea of how relatively comfortable a climate is, and how much energy is required in that climate to heat and cool a building through a typical year.

Hottest locations in the world by CDD:

 

Mecca, Saudi Arabia 8,176 (hands-down the #1 hottest large city in the world)
Khartoum, Sudan 7,833 (hottest national capital)
Bangkok, Thailand 6,680
Singapore 6,192
Manila, Philippines 6,027

Jakarta, Indonesia 5,905

Manaus, Brazil 5,861
Mumbai, India 5,756
Recife, Brazil 5,718

Dubai, UAE 5,702

Death Valley, CA, USA 5,600 (hottest location in USA, uninhabited)
Lagos, Nigeria 5,577
San Juan, PR, USA 5,588 (hottest large city in USA)

Key West, FL, USA 4,825 (hottest in mainland USA)
Phoenix, AZ, USA 4,620 (hottest US city with metro >1 million pop)

 

 

Coldest locations in the world by HDD, isolated outposts like Eureka, Canada not included:

Verkhoyansk, Russia 21,322 (coldest city with > 1,000 pop in world)
Barrow, AK, Alaska, USA 19,428 (coldest in USA)
Noril'sk, Russia 18,307 (coldest city with > 100,000 pop)

Yakutsk, Russia 17,788
Iqaluit, Canada 18,211 (coldest over 1,000 pop in Canada)
Churchill, MB, Canada 16,322

Yellowknife, NT, Canada 14,861

Fairbanks, AK, USA 13,531
Ulaanbaatar, Mongolia 12,537
Leadville, CO, USA 10,877 (coldest town in lower 48 USA)

Novosibirsk, Russia 10,650 (coldest metro > 1 million pop)

Winnipeg, MB, Canada 10,400

Edmonton, AB, Canada 10,274
International Falls, MN, USA 10,080
Moscow, Russia 9,168
Minneapolis, MN, USA 7,574 (coldest metro > 1 million pop in USA)


Least amount of HDD, CDD, Total

Uruapan, Mexico 276, 429, 755 (most "agreeable" climate in world in terms of temperature?)
Huambo, Angola 429, 364, 793
Guatemala City, Guatemala 62, 749, 811
Nairobi, Kenya 155, 742, 897 (most "agreeable" major city in world?)

Mexico City, Mexico 954, 122, 1,076
Cochabamba, Bolivia 934, 153, 1,087

Addis Ababa, Ethiopia 1189, 0, 1,189

Iquique, Chile 766, 677, 1,443

San Diego, CA, USA 1166, 802, 1,968 (most "agreeable" major city in US?)

 

Degree days are all based on degrees Fahrenheit

 

 


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#2
wx_statman

Posted 04 January 2015 - 11:13 AM

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Interesting stuff!

 

Mecca's climate is ridiculous. 86/66 in the coldest month and 111/83 for the warmest. Hotter than Death Valley over the course of a year but with a population of 1.7 million.


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#3
Glacier

Posted 09 January 2015 - 04:22 PM

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Using 18C/65F as the cutoff is kinda dumb if you ask me. 65F means 90F in the day and 40F at night where I grew up in central BC. This is considered an air conditioning sort of day.

 

But just to humour you folks, let's just pretend 18C/65F is ideal. 

 

The best place in Canad to live is Victoria, BC with 4618 of heating + cooling degree days (degrees F). Outside of BC, Windsor, Ontario is next with 6730 CDD + HDD.

 

Of course, the north is the worst with up to 24,104 CDD + HDD at Eureka, Nunavut. All of these are HDD.

 

Victoria only has 4516 HDD. Outside of BC, Windsor, Ontario is the lowest with 5755 HDD.

 

Windsor also has the greatest number of CDD in Canada with 975. Spences Bridge, BC is the highest outside of southern Ontario with 377, though the weather station stopped in 2002, and thus missed the warmest summer decade on record. I would estimate it to be well over 400 for the entire 30 year period.  



#4
Glacier

Posted 09 January 2015 - 04:24 PM

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Interesting stuff!

 

Mecca's climate is ridiculous. 86/66 in the coldest month and 111/83 for the warmest. Hotter than Death Valley over the course of a year but with a population of 1.7 million.

Is there any wonder why a lot of angry men come from that area?


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#5
IbrChris

Posted 10 January 2015 - 04:04 PM

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Using 18C/65F as the cutoff is kinda dumb if you ask me. 65F means 90F in the day and 40F at night where I grew up in central BC. This is considered an air conditioning sort of day.

 

But just to humour you folks, let's just pretend 18C/65F is ideal. 

 

The best place in Canad to live is Victoria, BC with 4618 of heating + cooling degree days (degrees F). Outside of BC, Windsor, Ontario is next with 6730 CDD + HDD.

 

Of course, the north is the worst with up to 24,104 CDD + HDD at Eureka, Nunavut. All of these are HDD.

 

Victoria only has 4516 HDD. Outside of BC, Windsor, Ontario is the lowest with 5755 HDD.

 

Windsor also has the greatest number of CDD in Canada with 975. Spences Bridge, BC is the highest outside of southern Ontario with 377, though the weather station stopped in 2002, and thus missed the warmest summer decade on record. I would estimate it to be well over 400 for the entire 30 year period.  

HDD and CDD are tuned to the 65F cutoff because that has been shown to be the point where cooling and heating effects equilibrate regarding energy to cool/heat a building. If the outside temperature remained a constant 65F you would neither have to cool nor heat indoor spaces. If in a region with high diurnal swings yes you could have to heat a building in the early morning and overnight, and cool it for a couple hours in the late afternoon/early evening. 50 degree diurnal range (90/40) isn't the norm for where 90% of the population lives however.


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#6
IbrChris

Posted 10 January 2015 - 04:08 PM

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Uruapan, Mexico actually has a pretty sweet climate if you ask me...agreeable temps year round and a good deal of thunderstorms in summer. Subtropical highland climate without being so high that frosts are common.

 

http://en.wikipedia.org/wiki/Uruapan

Jan: 77/48
July: 79/59

Rec: 102/30

 

warmest month May: 86/57, mean 71.6 or about 2-3 deg warmer than Portland in July/August.

 

4-5 month rainy season (mostly convective) with 60" a year.


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The Pacific Northwest: Where storms go to die.


#7
IbrChris

Posted 30 June 2015 - 07:34 PM

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Using 18C/65F as the cutoff is kinda dumb if you ask me. 65F means 90F in the day and 40F at night where I grew up in central BC. This is considered an air conditioning sort of day.

But just to humour you folks, let's just pretend 18C/65F is ideal.

Sorry about the "necro-bump" on the thread but I'd like to ask Glacier how often a 50 degree range occurs in south-central BC at a station located near a reasonable sized city of say 1,000 or more? My guess is pretty rare in the absence of an arctic front.

Also assuming your 90/40 occurs in early/mid summer you probably only spend at most 6-7 hours above 80, for instance from about noon-1pm to 6-7 PM.

The Pacific Northwest: Where storms go to die.


#8
Glacier

Posted 28 July 2015 - 12:40 PM

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Sorry about the "necro-bump" on the thread but I'd like to ask Glacier how often a 50 degree range occurs in south-central BC at a station located near a reasonable sized city of say 1,000 or more? My guess is pretty rare in the absence of an arctic front.

Also assuming your 90/40 occurs in early/mid summer you probably only spend at most 6-7 hours above 80, for instance from about noon-1pm to 6-7 PM.

Come to think about it, in the summer when we do have a cool day, it's because of rain, so the diurnal range isn't very big. It was only the low 60s on Saturday with lows below 50, but there's no way anyone would turn on their heat because of that one day blip between 95 degree heatwaves. 

 

Anyway, 50 degree swings are more common in summer than in winter. 40 degrees is very common, say 1/3 of days in the summer in much of the south, and 45 degrees is fairly common, but 50 degrees is very rare. I just checked out a few spots now, Castlegar, Midway, etc, and could only find one place with more than 50 degree swings, and that was Tatlayoko Lake with swings of 51 and 52 degrees on June 27th and 28th. (92F in the afternoon for the second day). The population is only 100 or so in that area.  

 

EDIT: The daily temperature in Tatlayoko Lake can push 60 degrees, both during the winter weather changes, and during summer heatwaves, well actually during September heat waves when it cools off a lot more at night. The high to low records are the same as the low to high records. 33C/ 59.4F.


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#9
Chriskey2015

Posted 11 August 2015 - 04:09 AM

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wow, Its nice here at Philippines that's why they say "It's more fun here in the Philippines"


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#10
IbrChris

Posted 21 November 2015 - 12:53 PM

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wow, Its nice here at Philippines that's why they say "It's more fun here in the Philippines"

Manila is pretty warm and humid but one can adjust to that given some time. Higher elevations are probably very agreeable.


The Pacific Northwest: Where storms go to die.


#11
IbrChris

Posted 21 November 2015 - 12:55 PM

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Come to think about it, in the summer when we do have a cool day, it's because of rain, so the diurnal range isn't very big. It was only the low 60s on Saturday with lows below 50, but there's no way anyone would turn on their heat because of that one day blip between 95 degree heatwaves. 

 

Anyway, 50 degree swings are more common in summer than in winter. 40 degrees is very common, say 1/3 of days in the summer in much of the south, and 45 degrees is fairly common, but 50 degrees is very rare. I just checked out a few spots now, Castlegar, Midway, etc, and could only find one place with more than 50 degree swings, and that was Tatlayoko Lake with swings of 51 and 52 degrees on June 27th and 28th. (92F in the afternoon for the second day). The population is only 100 or so in that area.  

 

EDIT: The daily temperature in Tatlayoko Lake can push 60 degrees, both during the winter weather changes, and during summer heatwaves, well actually during September heat waves when it cools off a lot more at night. The high to low records are the same as the low to high records. 33C/ 59.4F.

Yeah we have isolated spots in the Great Basin which experience 60 degree diurnal changes several times a year typically in late spring and early fall...Ely, Charleston and Wildhorse Reservoir in NE Nevada come to mind. There are also spots that have recorded a record high and record low on the same date, though this is rare.

 

Of course Browning, MT and Loma, MT both have had diurnal ranges of nearly 100 degrees associated with arctic fronts. I would guess some spots in southern Alberta have seen similar events albeit very rare.


The Pacific Northwest: Where storms go to die.






Also tagged with one or more of these keywords: climate, CDD, HDD, heat, cold