Thursday, April 19, 2012

The Perfect Climate - Part 5

by Conroy

Rio, unsurprisingly, has one of the best climates in the world
I spent the first four parts of this series exploring my climate ranking system and applying it to American cities in search of the "perfect climate". Now it’s time to expand the rankings to the whole world. Below I’ve ranked 150 cities [1] using both my original formula, which favors warm places, and the alternative formula presented in Part 4, which favors consistently temperate locations.

This is the fifth post in my “Perfect Climate” series. To check out the first four, use the following links:
 As a reminder, warm cities are places with annual mean temperatures in the mid to upper 70s (or higher) and little seasonal variance. Examples include Miami, Rio de Janeiro, and Bangalore, India. Temperate cities are places with annual mean temperatures in the mid 60s (no higher) and little seasonal variance, and especially no really hot months. Examples include San Diego, Mexico City, and Cape Town, South Africa. I’m presenting dual rankings because these preferences seem to predominate when it comes to climate taste. For both approaches, cold cities fare poorly.

One thing to note regarding the “warm cities” ranking, in my original formula I assumed that the higher the annual mean temperature the better. I was examining American cities the warmest of which is Honolulu, Hawaii with an annual mean of 77.5 degrees. However, when I expanded my rankings to encompass all the world’s cities, I ran into a problem: much of the Earth is very hot. Many cities across Africa and Asia have annual mean temperatures that exceed 80 degrees. While I enjoy warm conditions, even I have to admit that there’s an upper limit above which the climate grows too hot. I decided to modify my original formula to penalize cities where the annual mean temperature exceeds 78 degrees [2]. This adjustment works the same as the temperature penalty applied in the alternative (temperate) climate formula for cities with annual mean temperatures above 65 degrees (see Part 4).

The World’s Climate
Before jumping to the actual rankings, I'll note a few general impressions from my review of climates for hundreds of places in all parts of the world.
Latitude and elevation combine to give Nairobi a pleasant climate
  • Large portions of South America, Africa, and Asia are located at low latitudes but relatively high elevations. This combination of tropical locations perched well above sea level is a magic formula for a favorable climate. The tropical latitude results in consistent solar radiation throughout the year, which means little temperature variance, but the higher elevations moderate the temperature. Cities in these zones include Nairobi, Sao Paulo, and Bangalore, India. Each boasts a climate that would be far hotter (and far less bearable) if located near sea level.
  • It’s surprising how few large cities are located in really cold places. Only six cities experience mean low temperatures in the single digits (F) during one or more winter months: Minneapolis, Minnesota, Ottawa, Montreal, and Edmonton, Canada, and Shenyang and Harbin, China. Indeed, Harbin (China's tenth largest city), in the far northeast of China right on the edge of Siberia, is the only major global city to experience mean low temperatures below zero (F) for any month of the year. It’s appropriately nicknamed the “Ice City”, and the winter cold there is worse than in Arctic places like Nome, Alaska. This relative paucity of large cities in places with harsh winters is another demonstration that the great majority of people the world over choose not to live in cold climates.
  • Conversely, cities with average high temperatures above 100 degrees during one or more summer months are common across the American southwest, Saharan Africa, the Middle East, and South Asia. The highest monthly mean temperature for any major city belongs to Baghdad, Iraq where the July high is a heat-stroke-inducing 111 degrees. That’s nearly as hot as Death Valley during high summer. Other "hot" cities include Phoenix, Riyadh, Delhi, and Khartoum. In fact, the capital of Sudan has the highest annual mean temperature of any major city at 85.8 degrees. (It's worth noting that I developed this climate system thinking of the U.S. where air conditioning is ubiquitous. That's certainly not the case through the "hot" world, so the warm rankings should be considered with that in mind; warm may not be so pleasant where it can't be escaped.)
  • Perhaps the continent with the most consistently superb climate is South America. All of that continent’s major cities score well on both the warm and temperate rankings. And of all nations, Brazil’s big cities boast almost universally excellent climates. This is also true of the other large southern hemisphere country, Australia, where all of its large cities also have friendly climates. This is a major contrast to the large nations of the northern hemisphere that are either cold (Canada and Russia) or feature widely varying climates (U.S. and China).
  • If you’re interested in finding unvarying temperatures, then follow the Equator. Quito, Ecuador, Manaus and Belem, Brazil, Male in the Maldives, Kuala Lumpur, Singapore, and Brunei all lie on or near the Equator and are among the relatively short list of cities that have annual temperature variances of less than 3 degrees.
  • Finally, it’s interesting to compare the most extreme climate on Earth to my climate rankings. Russia’s Vostok Station in Antarctica is renowned as the coldest place on the planet, the Pole of Cold [3]. The lowest ever measured surface temperature of -128.6 degrees was recorded there in 1983. The average August low temperature is -97 degrees, and it earns a climate score of -105. The temperatures at Vostok are comparable to the surface of Mars in winter. It puts things into perspective when evaluating the “perfect” and “terrible” climates across the globe. Harbin's climate is far closer to sunny Rio de Janeiro's than it is to interior Antarctica.
Ice sculptures in Harbin, the world's coldest big city

Now on to the rankings.




The Perfect Climate Global Rankings
If you prefer warm places then Bandung, Indonesia is the place for you. Located on the island of Java southeast of Jakarta at an elevation of 2,500 feet, it has year-long highs in the low 80s and lows in the upper 60s. If you prefer a temperate climate then it gets no better than Nairobi, Kenya. Located in the south of the country at an elevation of 5,900 feet, it has year round mild temperature with highs in the upper 60s and low 70s and lows in the lower to mid 50s. Unsurprisingly, the “worst” climates belong to the cold cities of Canada, Russia, and China.

[Note that these rankings, along with many other rankings by continent/region/country are available at Conroy’s Climate Rankings page of this blog.]


Climate Rankings for 150 Global Cities
Warm Cities
Temperate Cities
Rk
Urban Area
Climate Score
Rk
Urban Area
Climate Score
1
Bandung, ID
 56.9
1
Nairobi, KE
44.2
2
 Caracas, VE
 55.3
2
Lima, PE
43.8
3
 Brasilia, BR
 53.8
3
Medellin, CO
42.0
4
 Salvador, BR
 52.8
4
Bandung, ID
41.0
5
Rio de Janeiro, BR
51.4
5
Sao Paulo, BR
40.5
6
 Luanda, AO
 50.0
6
Curitiba, BR
40.0
7
Bangalore, IN
 49.6
7
San Diego, US
39.7
8
 Dar es Salaam, TZ
 49.3
8
Caracas, VE
39.5
9
 Belo Horizonte, BR
 49.0
9
Brasilia, BR
39.3
10
 Accra, GH
 48.8
10
Mexico City, MX
39.0
11
 Recife, BR
 48.8
11
Belo Horizonte, BR
37.8
12
 Fortaleza, BR
48.8
12
Durban, ZA
37.3
13
 Dakar, SN
 48.3
13
Los Angeles, US
36.8
14
 Kinshasa, CD
 48.3
14
Casablanca, MA
35.8
15
 San Juan, PR
 48.3
15
San Francisco, US
35.4
16
Abidjan, CI
 48.0
16
Cape Town, ZA
35.3
17
 Lagos, NG
47.8
17
Sydney, AU
35.1
18
Surabaya, ID
47.3
18
Luanda, AO
34.8
19
 Kuala Lumpur, MY
 46.8
19
Guadalajara, MX
34.8
20
 Singapore
 46.5
20
Rio de Janeiro, BR
34.3
21
Manila, PH
 46.3
21
Brisbane, AU
34.3
22
 Jakarta, ID
45.3
22
Bogota, CO
34.1
23
 Miami, US
 44.9
23
Salvador, BR
32.8
24
Ho Chi Minh City, VN
44.5
24
Bangalore, IN
32.5
25
 Sao Paulo, BR
 44.2
25
Porto Alegre, BR
32.3
26
Lima, PE
43.8
26
Johannesburg, ZA
31.9
27
 Guadalajara, MX
 43.3
27
Hong Kong, CN
31.8
28
 Mumbai, IN
 43.3
28
Dakar, SN
31.8
29
Medellin, CO
 43.1
29
Dar es Salaam, TZ
30.8
30
 Yangon, MM
 42.8
30
Lisbon, PT
30.6
31
Durban, ZA
 42.5
31
Recife, BR
30.3
32
Bangkok, TH
 42.3
32
Fortaleza, BR
30.3
33
 Pune, IN
41.7
33
Accra, GH
30.3
34
 Hong Kong, CN
 41.4
34
San Juan, PR
30.0
35
Karachi, PK
41.3
35
Tampa, US
29.9
36
 Kano, NG
 39.8
36
Kinshasa, CD
29.8
37
 Kolkata, IN
 39.0
37
Perth, AU
29.7
38
Jeddah, SA
 39.0
38
Melbourne, AU
29.7
39
 Hyderabad, IN
 38.8
39
Abidjan, CI
29.5
40
 Brisbane, AU
38.6
40
Lagos, NG
29.3
41
 Chennai, IN
 38.0
41
Miami. US
29.0
42
 Surat, IN
 37.8
42
Alexandria, EG
29.0
43
Tampa, US
 37.8
43
Kuala Lumpur, MY
28.3
44
 Nairobi, KE
 37.7
44
Surabaya, ID
28.3
45
Taipei, TW
 37.4
45
Tripoli, LY
28.3
46
 Dhaka, BD
 36.5
46
Singapore
28.0
47
 San Diego, US
 36.0
47
Tel Aviv, IL
28.0
48
 Porto Alegre, BR
35.8
48
Buenos Aires, AR
28.0
49
Los Angeles, US
35.5
49
Manila, PH
27.8
50
 Sydney, AU
 35.1
50
Taipei, TW
26.8
51
 Curitiba, BR
34.5
51
Jakarta, ID
25.8
52
 Alexandria, EG
 34.4
52
Pune, IN
25.5
53
Guangzhou, CN
 34.1
53
Guangzhou, CN
25.3
54
 Casablanca, MA
 33.8
54
Ho Chi Minh City, VN
25.0
55
 Monterrey, MX
 33.6
55
Tunis, TN
25.0
56
Ahmedabad, IN
33.5
56
Mumbai, IN
24.3
57
 Cape Town, ZA
 32.3
57
Cairo, EG
24.1
58
 Mexico City, MX
 32.0
58
Barcelona, ES
24.1
59
Tel Aviv, IL
 31.6
59
Monterrey, MX
24.0
60
Cairo, EG
 31.4
60
Yangon, MM
23.8
61
Khartoum, SD
 30.8
61
Algiers, DZ
23.1
62
 Perth, AU
 30.2
62
Karachi, PK
22.8
63
 Houston, US
 29.5
63
Houston, US
22.8
64
Buenos Aires, AR
 29.0
64
Santiago, CL
22.8
65
 Dubai, AE
 28.8
65
Bangkok, TH
21.8
66
Bogota, CO
 28.1
66
Kano, NG
21.3
67
 Lisbon, PT
 28.1
67
Naples, IT
21.3
68
Johannesburg, ZA
 27.9
68
Kolkata, IN
20.0
69
Jaipur, IN
27.9
69
Hyderabad, IN
19.8
70
 San Francisco, US
 27.9
70
Fuzhou, CN
19.8
71
Fuzhou, CN
 27.3
71
Athens, GR
19.6
72
 Tunis, TN
 26.6
72
Jeddah, SA
18.0
73
 Delhi, IN
26.4
73
Surat, IN
17.8
74
 Melbourne, AU
26.2
74
Dublin, IE
17.7
75
 Algiers, DZ
 24.6
75
Portland, US
17.4
76
Tripoli, LY
24.1
76
Chengdu, CN
17.3
77
 Barcelona, ES
 24.1
77
Rome, IT
17.3
78
Lahore, PK
 23.4
78
Istanbul, TR
17.0
79
 Athens, GR
22.1
79
Chonquing, CN
16.8
80
 Chonqing, CN
21.8
80
Seattle, US
16.7
81
Santiago, CL
21.3
81
Paris, FR
16.4
82
 Phoenix, US
 21.0
82
Dhaka, BD
16.0
83
 Naples, IT
20.7
83
Chennai, IN
15.5
84
 Chengdu, CN
 19.8
84
London, UK
14.9
85
 Istanbul, TR
 18.0
85
Atlanta, US
14.6
86
 Dallas, US
 18.0
86
Madrid, ES
13.9
87
 Rome, IT
17.8
87
Manchester, UK
13.8
88
 Riyadh, SA
17.5
88
Tokyo, JP
13.5
89
 Atlanta, US
16.6
89
Ahmedabad, IN
13.0
90
 Tokyo, JP
16.5
90
Brussels, BE
13.0
91
 Damascus, SY
 16.4
91
Damascus, SY
12.9
92
 Nanchang, CN
16.1
92
Jaipur, IN
12.8
93
 Hangzhou, CN
15.1
93
Essen, DE
12.3
94
 Osaka, JP
14.9
94
Nanchang, CN
12.1
95
 Dublin, IE
 14.7
95
Dallas, US
12.0
96
 Madrid, ES
14.4
96
Osaka, JP
11.9
97
Seattle, US
 14.2
97
Busan, KR
11.9
98
 Portland, US
13.9
98
Delhi, IN
11.8
99
 Paris, FR
13.9
99
Hangzhou, CN
11.6
100
 Shanghai, CN
13.6
100
Shanghai, CN
10.6
101
Busan,  KR
 13.4
101
Vancouver, CN
10.6
102
Wuhan, CN
13.4
102
Nagoya, JP
10.5
103
 Baghdad, IQ
13.2
103
Phoenix, US
10.0
104
 Nagoya, JP
13.0
104
Lahore, PK
10.0
105
London, UK
12.4
105
Vienna, AT
9.6
106
 Nanjing, CN
 11.4
106
Wuhan, CN
9.4
107
 Manchester, UK
10.8
107
Nanjing, CN
9.4
108
 Baltimore, US
9.9
108
Geneva, CH
8.9
109
 Brussels, BE
 9.0
109
Frankfurt, DE
8.8
110
Milan, IT
9.0
110
Milan, IT
8.5
111
 Washington, US
9.0
111
Hamburg, DE
8.4
112
 Tehran, IR
8.8
112
Berlin, DE
8.2
113
Essen, DE
8.3
113
Baltimore, US
7.4
114
Vancouver, CA
 7.8
114
Dubai, AE
7.3
115
 Vienna, AT
 7.6
115
Copenhagen, DK
7.0
116
 Frankfurt, DE
 6.8
116
Khartoum, SD
6.3
117
 Geneva, CH
6.4
117
Washington, US
6.0
118
 Berlin, DE
 6.2
118
Munich, DE
5.5
119
 Philadelphia, US
5.7
119
Zurich, CH
4.4
120
 Hamburg, DE
 5.4
120
Philadelphia, US
4.2
121
 Xi'an, CN
5.4
121
Tehran, IR
3.8
122
 New York, US
 4.3
122
Xi'an, CN
3.4
123
 Copenhagen, DK
 4.0
123
New York, US
2.8
124
Seoul,  KR
 3.8
124
Seoul, KR
1.8
125
St. Louis, US
 3.6
125
Stockholm, SE
1.4
126
Boston, US
 2.5
126
Ankara, TR
1.1
127
 Munich, DE
2.0
127
Denver, US
1.1
128
 Kabul, AF
 1.8
128
Boston, US
1.0
129
Tianjin, CN
 1.6
129
Baghdad, IQ
0.8
130
Chicago, US
 1.3
130
Kabul, AF
0.8
131
 Zurich, CH
0.9
131
Warsaw, PL
0.7
132
 Beijing, CN
 0.3
132
St. Louis, US
0.6
133
 Detroit, US
0.1
133
Chicago, US
-0.2
134
Pittsburgh, US
 0.1
134
Pittsburgh, US
-0.4
135
Cleveland, US
-0.2
135
Cleveland, US
-0.7
136
 Denver, US
 -0.4
136
Riyadh, SA
-1.0
137
 Warsaw, PL
-1.3
137
Tianjin, CN
-1.4
138
 Ankara, TR
 -1.4
138
Beijing, CN
-1.7
139
 Stockholm, SE
-1.6
139
Detroit, US
-1.9
140
 Sapporo, JP
 -1.8
140
Sapporo, JP
-2.3
141
Kiev, UA
 -4.6
141
Kiev, UA
-3.6
142
 St. Petersburg, RU
 -7.6
142
 Saint Petersburg, RU
-5.6
143
Toronto, CA
-10.0
143
Toronto, CA
-8.5
144
Moscow, RU
-11.6
144
 Moscow, RU
-9.1
145
 Shenyang, CN
 -12.2
145
 Ottawa, CA
-12.9
146
 Minneapolis, US
 -12.6
146
 Minneapolis, US
-13.1
147
Ottawa, CA
 -14.9
147
Shenyang, CN
-13.2
148
 Montreal, CA
 -15.7
148
 Montreal, CA
-14.2
149
 Edmonton, CA
 -19.5
149
 Edmonton, CA
-17.0
150
 Harbin, CN
-27.6
150
Harbin, CN
-28.6

Bandung, perhaps blessed with the world's best climate

---

NOTES:

[1] The world’s 100 largest urban areas plus an additional 50 noteworthy cities. I chose which are noteworthy (e.g., Rome and my hometown of Baltimore).

[2] 78 degrees is an arbitrary value, but it seemed like a reasonable limit for warm comfort (it also saves me from having to modify my American city rankings.

[3] Thanks to a good friend and faithful reader for pointing this out to me.

1 comment:

  1. Conroy,

    penalising cities where the average temperature exceeds 78 degrees Fahrenheit or 25 degrees Celsius, I feel, is too lenient. I have been in Singapore, with an average temperature of 86˚ Fahrenheit, and it is very uncomfortable especially with the humidity and the extreme uniformity of the weather throughout the year.

    As I may have noted before, the best method I can think for ranking cities is on heating and cooling degree days with a base of 60˚F or 16˚C. However, one cooling degree day causes more discomfort than one heating degree day, and I have proposed using a ratio of 3:1 I.e., I would have 3 points subtracted per cooling degree day and one per heating degree day.

    ReplyDelete