Connect with us

Maps

Mapping the Unequal Distribution of Global Precipitation

Published

on

Click to view this graphic in a higher-resolution.

A map with global precipitation patterns. One half of the world, in blue, receives more than one meter of rain (or snow) in a year, the other half receives less.

Mapping the Unequal Distribution of Global Precipitation

On average, nearly one meter (39 inches) of rain or snow falls on the Earth in a year. However, differences in latitude, winds, changes in the Earth’s surface, and the planet’s tilt, make for an unequal distribution of global precipitation.

Cartographer Perrin Remonté uses data from Chelsea Climate to visualize this by splitting the world in two. One half, in blue, receives more than one meter of rain (or snow) in a year, the other half receives less.

What Affects Global Precipitation Patterns?

From the water cycle we know that precipitation starts with evaporation. However, moist air needs to cool and then condense to come down as rain (or snow). Below we list some major factors influencing precipitation.

  • Proximity to water: Oceans and lakes provide a constant source of moisture.
  • Lower latitudes: Areas at, or close to the equator, are hotter and this can increase evaporation from nearby water bodies.
  • Topography: Mountain ranges, especially along coasts, force warm air to rise and cool, resulting in rain or snow on the windward side and dry rain shadows on the lee side.
  • Trade winds: Persistent, easterly surface winds blow from subtropical high-pressure areas toward the equator, carrying moist air from the ocean to the land.

So, how do these factors interact to form the global precipitation map visualized above?

Ranked: Countries Which Receive Highest Rain or Snow

A quick look at the map reveals some obvious insights. For one, most of the Earth that receives above average rainfall is covered by oceans. After all, oceans are 71% of the Earth’s surface, but, crucially, they provide the moisture for precipitation to occur.

Over landmasses, we see more complex interaction between earlier listed factors. Here’s the average rainfall received by each country in 2020, sourced from the World Bank.

RankCountry/TerritoryAverage Precipitation
(mm, 2020)
1🇨🇴 Colombia3,240
2🇸🇹 Sao Tome
& Principe
3,200
3🇵🇬 Papua New
Guinea
3,142
4🇸🇧 Solomon
Islands
3,028
5🇵🇦 Panama2,928
6🇨🇷 Costa Rica2,926
7🇼🇸 Samoa2,880
8🇲🇾 Malaysia2,875
9🇧🇳 Brunei
Darussalam
2,722
10🇮🇩 Indonesia2,702
11🇧🇩 Bangladesh2,666
12🇫🇯 Fiji2,592
13🇸🇱 Sierra Leone2,526
14🇸🇬 Singapore2,497
15🇱🇷 Liberia2,391
16🇬🇾 Guyana2,387
17🇬🇩 Grenada2,350
18🇵🇭 Philippines2,348
19🇸🇷 Suriname2,331
20🇸🇨 Seychelles2,330
21🇱🇨 St. Lucia2,301
22🇳🇮 Nicaragua2,280
23🇪🇨 Ecuador2,274
24🇧🇹 Bhutan2,200
25🇹🇹 Trinidad
& Tobago
2,200
26🇬🇶 Equatorial Guinea2,156
27🇲🇲 Myanmar2,091
28🇩🇲 Dominica2,083
29🇵🇷 Puerto Rico2,054
30🇯🇲 Jamaica2,051
31🇻🇪 Venezuela2,044
32🇲🇺 Mauritius2,041
33🇻🇺 Vanuatu2,000
34🇬🇹 Guatemala1,996
35🇭🇳 Honduras1,976
36🇲🇻 Maldives1,972
37🇮🇸 Iceland1,940
38🇰🇭 Cambodia1,904
39🇱🇦 Laos1,834
40🇬🇦 Gabon1,831
41🇻🇳 Viet Nam1,821
42🇸🇻 El Salvador1,784
43🇧🇷 Brazil1,761
44🇵🇪 Peru1,738
45🇳🇿 New Zealand1,732
46🇱🇰 Sri Lanka1,712
47🇧🇿 Belize1,705
48🇯🇵 Japan1,668
49🇬🇳 Guinea1,651
50🇨🇬 Congo1,646
51🇹🇭 Thailand1,622
52🇨🇲 Cameroon1,604
53🇻🇨 St. Vincent &
the Grenadines
1,583
54🇬🇼 Guinea-Bissau1,577
55🇨🇩 DRC1,543
56🇨🇭 Switzerland1,537
57🇨🇱 Chile1,522
58🇲🇬 Madagascar1,513
59🇳🇵 Nepal1,500
60🇹🇱 Timor-Leste1,500
61🇦🇱 Albania1,485
62🇭🇹 Haiti1,440
63🇰🇳 St. Kitts
& Nevis
1,427
64🇧🇧 Barbados1,422
65🇳🇴 Norway1,414
66🇩🇴 Dominican
Republic
1,410
67🇨🇮 Cote d'Ivoire1,348
68🇨🇫 Central
African Republic
1,343
69🇨🇺 Cuba1,335
70🇺🇾 Uruguay1,300
71🇧🇸 Bahamas1,292
72🇧🇮 Burundi1,274
73🇰🇷 South Korea1,274
74🇬🇧 UK1,220
75🇷🇼 Rwanda1,212
76🇬🇭 Ghana1,187
77🇲🇼 Malawi1,181
78🇺🇬 Uganda1,180
79🇹🇬 Togo1,168
80🇸🇮 Slovenia1,162
81🇳🇬 Nigeria1,150
82🇧🇴 Bolivia1,146
83🇵🇾 Paraguay1,130
84🇮🇪 Ireland1,118
85🇭🇷 Croatia1,113
86🇦🇹 Austria1,110
87🇮🇳 India1,083
88🇹🇿 Tanzania1,071
89🇰🇵 North Korea1,054
90🇧🇯 Benin1,039
91🇲🇿 Mozambique1,032
92🇦🇬 Antigua
& Barbuda
1,030
93🇧🇦 Bosnia &
Herzegovina
1,028
94🇬🇪 Georgia1,026
95🇿🇲 Zambia1,020
96🇦🇴 Angola1,010
97🇱🇺 Luxembourg934
98🇰🇲 Comoros900
99🇸🇸 South Sudan900
100🇫🇷 France867
101🇵🇹 Portugal854
102🇪🇹 Ethiopia848
103🇧🇪 Belgium847
104🇬🇲 Gambia836
105🇮🇹 Italy832
106🇸🇰 Slovakia824
107🇱🇸 Lesotho788
108🇸🇿 Eswatini788
109🇳🇱 Netherlands778
110🇲🇽 Mexico758
111🇧🇫 Burkina Faso748
112🇺🇸 U.S.715
113🇩🇰 Denmark703
114🇩🇪 Germany700
115🇹🇯 Tajikistan691
116🇸🇳 Senegal686
117🇨🇿 Czechia677
118🇱🇻 Latvia667
119🇱🇧 Lebanon661
120🇿🇼 Zimbabwe657
121🇱🇹 Lithuania656
122🇬🇷 Greece652
123🇨🇳 China645
124🇷🇴 Romania637
125🇪🇸 Spain636
126🇰🇪 Kenya630
127🇪🇪 Estonia626
128🇸🇪 Sweden624
129🇲🇰 North Macedonia619
130🇧🇾 Belarus618
131🇧🇬 Bulgaria608
132🇵🇱 Poland600
133🇹🇷 Türkiye593
134🇦🇷 Argentina591
135🇭🇺 Hungary589
136🇺🇦 Ukraine565
137🇦🇲 Armenia562
138🇲🇹 Malta560
139🇨🇦 Canada537
140🇫🇮 Finland536
141🇦🇺 Australia534
142🇰🇬 Kyrgyz Republic533
143🇨🇾 Cyprus498
144🇿🇦 South Africa495
145🇵🇰 Pakistan494
146🇷🇺 Russia460
147🇲🇩 Moldova450
148🇦🇿 Azerbaijan447
149🇮🇱 Israel435
150🇧🇼 Botswana416
151🇵🇸 West Bank
& Gaza
402
152🇪🇷 Eritrea384
153🇲🇦 Morocco346
154🇦🇫 Afghanistan327
155🇹🇩 Chad322
156🇳🇦 Namibia285
157🇲🇱 Mali282
158🇸🇴 Somalia282
159🇸🇾 Syria252
160🇰🇿 Kazakhstan250
161🇸🇩 Sudan250
162🇲🇳 Mongolia241
163🇨🇻 Cabo Verde228
164🇮🇷 Iran228
165🇩🇯 Djibouti220
166🇮🇶 Iraq216
167🇹🇳 Tunisia207
168🇺🇿 Uzbekistan206
169🇾🇪 Yemen167
170🇹🇲 Turkmenistan161
171🇳🇪 Niger151
172🇴🇲 Oman125
173🇰🇼 Kuwait121
174🇯🇴 Jordan111
175🇲🇷 Mauritania92
176🇩🇿 Algeria89
177🇧🇭 Bahrain83
178🇦🇪 UAE78
179🇶🇦 Qatar74
180🇸🇦 Saudi Arabia59
181🇱🇾 Libya56
182🇪🇬 Egypt18

Note: Data for 34 countries/territories is missing from the source and has not been included in this dataset.

At the top of the list Colombia experienced 3,240 millimeters (125.8 inches) of rain in 2020. This is due to its equatorial location, proximity to the Intertropical Convergence Zone (where trade winds from both hemispheres meet), two coastlines, and the presence of the Andes mountain range.

In fact, the next 22 ranks are countries that lie at or near the equator or have significant coastlines that lead to higher than average rainfall.

Bhutan, ranked 24th with 2,200 mm (86.6 inches) of rain is the first completely landlocked country in the dataset. Despite this, the country is on the path of the southwest monsoon (a seasonal wind laden with moisture) originating in the Indian Ocean, which encounters the windward side of Himalayas, causing rainfall.

In many countries like India, China, and the U.S., the coasts receive above average rainfall compared to the landlocked regions inside the countries.

However, countries in North Africa, like Egypt and Libya, are arid despite their coasts. High-pressure weather systems prevent moist air from rising, mountains cause rain shadows, and cold ocean currents reduce the chance of steady evaporation. Additionally, the region is in the 30 degree latitude band around the equator where atmospheric conditions cause drier conditions, leading to deserts.

What Does Mapping Global Precipitation Tell Us?

Knowing rain and snow patterns is critical for scientists studying the Earth’s climate system, as it reveals the impact of factors like geography, topography, and ocean currents on local climes.

It also aids in short-term weather forecasting, predicting when and where rain or snow may occur.

Practically, this data helps in water management, monitoring drought and flood conditions, enabling quick responses to extreme weather events.

Where Does This Data Come From?

Sources: Climate data from Chelsea Climate, and precipitation data from the World Bank.

Note: The precipitation data from the World Bank is collected by the Food and Agriculture Organization of the United Nations (FAO) through annual questionnaires. Complete consistency across countries and over time is not possible.

green check mark icon

This article was published as a part of Visual Capitalist's Creator Program, which features data-driven visuals from some of our favorite Creators around the world.

Click for Comments

Maps

Mapped: High School Graduation Rates by State

West Virginia has the highest graduation rate, with 91% of its students graduating.

Published

on

This map shows the percentage of public school students who graduate with a regular diploma in each U.S. state.

Mapped: High School Graduation Rates by State

This was originally posted on our Voronoi app. Download the app for free on iOS or Android and discover incredible data-driven charts from a variety of trusted sources.

A high school diploma not only represents the development of essential knowledge and skills but is also a critical step toward personal and professional growth.

This graphic shows the percentage of public school students who graduate with a regular high school diploma in each U.S. state. Data is sourced from the U.S. Department of Education, National Center for Education Statistics, for the school year 2021–22.

West Virginia Has the Highest Graduation Rate

The U.S. average high school graduation rate was 87% in the school year 2021–22.

West Virginia has the highest graduation rate, with 91% of its students graduating. Meanwhile, the District of Columbia has the lowest graduation rate, with 76%.

StatePercentage
West Virginia91
Tennessee90
Wisconsin90
Kentucky90
Massachusetts90
Iowa90
Missouri90
Texas90
Virginia89
Kansas89
Connecticut89
Mississippi89
New Hampshire88
Delaware88
Utah88
Alabama88
Arkansas88
Indiana88
Florida87
Illinois87
Pennsylvania87
Nebraska87
California87
New York87
North Carolina86
Maryland86
Ohio86
Maine86
Hawaii86
Montana86
New Jersey85
North Dakota85
Georgia84
South Carolina84
Minnesota84
Washington84
Rhode Island83
Louisiana83
Vermont83
Colorado82
Wyoming82
Nevada82
Oregon81
Michigan81
Idaho80
Alaska78
Arizona77
District of Columbia76
New MexicoNot available
OklahomaNot available

Given that West Virginia typically struggles in rankings like this, this top placement might be surprising to some. This high graduation rate is part of a concerted effort by the state to increase its graduation rate.

In 2011, West Virginia’s graduation rate sat at 72% (which would put them dead last by today’s standards). How did the state see such a significant improvement? A data-driven early warning system was put in place to target individuals when they are at most risk of dropping out and using interventions to keep them on pace to graduate.

Alabama, also an early adopter of this system, saw a steep improvement in their graduation rate over the past decade and a half.

If you enjoy posts like these, check out Mapped: Personal Finance Requirements by State, which visualizes where high school students are required to take a personal finance course.

Continue Reading
Voronoi, the app by Visual Capitalist. Where data tells the story. Download on App Store or Google Play

Subscribe

Popular