Which of the following statements best explains why the average temperature of Calgary is colder than that of London in December?

Winnipeg, Manitoba has the coldest winter weather of any major Canadian city. It ranks first for the lowest average temperatures. Winnipeg also is Canada's city that most often drops to -30 degrees Celsius (-22 degrees Fahrenheit) or below and it is least likely to have a day above freezing during winter.

Other Prairie cities along with several in Ontario and Quebec round out the lists of Canada's coldest in winter.

The tables below list the major Canadian cities that rank for the lowest maximum and minimum temperature averages, the fewest freezing days and the most days of really cold weather.

The cities included in these rankings are Canada's largest metropolitan areas. These are the 33 urban regions that had over 100,000 people according to the 2011 census by Statistics Canada. The temperature data are averages of weather measurements made from 1981 to 2010.

Coldest Winter Climates

Daytime highs at Canada's coldest cities average less than -4 degrees Celsius (25 degrees Fahrenheit) during winter.

Average daily maximum temperature for December, January and February City High °F High °C
Winnipeg, Manitoba 15 -9.3
Saguenay, Quebec 18 -7.7
Regina, Saskatchewan 18 -7.6
Saskatoon, Saskatchewan 19 -7.3
Thunder Bay, Ontario 21 -6.2
Sudbury, Ontario 21 -6.0
Québec City, Quebec 21 -5.9
Trois-Rivières, Quebec 23 -4.9
Edmonton, Alberta 24 -4.4

At ten Canadian cities the nighttime lows average less than -13 °C (8.4 °F) throughout winter.

Average daily minimum temperature in December, January and February City Low °F Low °C
Winnipeg, Manitoba -2 -19.2
Saguenay, Quebec -1 -18.3
Regina, Saskatchewan -1 -18.2
Thunder Bay, Ontario -1 -18.1
Saskatoon, Saskatchewan 2 -16.5
Sudbury, Ontario 4 -15.5
Sherbrooke, Quebec 4 -15.4
Québec City, Quebec 4 -15.4
Trois-Rivières, Quebec 6 -14.5
Edmonton, Alberta 8 -13.4

Lowest Temperatures

Eleven of Canada's cities can expect at least one night of -30 °C weather each winter.

Average number of days in winter when the temperature drops below -30 °C (-22 °F). City Days
Winnipeg, Manitoba 12
Regina, Saskatchewan 11
Thunder Bay, Ontario 7
Saskatoon, Saskatchewan 7
Saguenay, Quebec 7
Sherbrooke, Quebec 5
Calgary, Alberta 3
Sudbury, Ontario 3
Edmonton, Alberta 3
Trois-Rivières, Quebec 3
Québec City, Quebec 1

These Canadian cities have fewer than 30 days a winter when the temperature gets warm enough to melt ice and snow.

Average number of days when the temperature rises above 0 °C (32 °F) in December, January and February. City Days
Winnipeg, Manitoba 13
Saguenay, Quebec 15
Sudbury, Ontario 19
Regina, Saskatchewan 21
Québec City, Quebec 21
Saskatoon, Saskatchewan 21
Thunder Bay, Ontario 22
Trois-Rivières, Quebec 23

In order to continue enjoying our site, we ask that you confirm your identity as a human. Thank you very much for your cooperation.


Both the Arctic (North Pole) and the Antarctic (South Pole) are very cold because they get very little direct sunlight. The Sun is always low on the horizon, even in the middle of summer. In winter, the Sun is so far below the horizon that it doesn't come up at all for months at a time. So the days are just like the nights — cold and dark.

Even though the North Pole and South Pole are "polar opposites," they both get the same amount of sunlight. But the South Pole is a lot colder than the North Pole. Why? Well, the poles are polar opposites in other ways too.

The Arctic is an ocean surrounded by land. The Antarctic is land surrounded by ocean.


The Arctic is the North Pole, and the South Pole is in Antarctica. The poles are on the top of the Earth, and on the bottom of the Earth, respectively. Based on these maps, you can see that the Arctic is an ocean surrounded by land, while Antarctica is land surrounded by ocean on all sides. Credit: NASA/JPL-Caltech.


The ocean under the Arctic ice is cold, but still warmer than the ice in the glacier Antarctic! So the ocean warms the air a bit.

Antarctica is dry — and high. Under all of Antarctica's ice and snow is land, not ocean. And it has many mountains. The height of the surface is called "elevation" — much of Antarctica's mountains are very tall and rise super high above sea level. So, the Antarctic is at a much higher elevation than the Arctic. The average elevation of Antarctica is about 7,500 feet (2.3 kilometers). And the higher you go, the colder it gets. The Antarctic ice is super thick — up to 3 miles thick! The Antarctic ice forms a huge plateau that sits high above sea level.


This 3-D topographical view of Antarctica gives an idea of its high elevations and mountains. Credit: NASA/JPL-Caltech.


The main reason that the South Pole is so much colder than the North Pole is because of the strength of the winds blowing around the poles. Antarctic winds are very strong and stop warmer air from mixing with the polar air. This also happens in the Arctic, but winds surrounding the North Pole are not as strong. Because of this, warmer air from the warmer mid-latitudes is able to mix with polar air, making the Arctic warmer.

Check out the table below to see just how much colder the South Pole is than the North Pole! Brrrrr!


Time of year Average (mean) temperature
North Pole South Pole
Summer 32° F (0° C) −18° F (−28.2° C)
Winter −40° F (−40° C) −76° F (−60° C)

Climate Classification

The Köppen Climate Classification System is the most widely used system for classifying the world's climates. Its categories are based on the annual and monthly averages of temperature and precipitation. The Köppen system recognizes five major climatic types; each type is designated by a capital letter.

A - Tropical Moist Climates: all months have average temperatures above 18° Celsius.

B - Dry Climates: with deficient precipitation during most of the year.

C - Moist Mid-latitude Climates with Mild Winters.

D - Moist Mid-Latitude Climates with Cold Winters.

E - Polar Climates: with extremely cold winters and summers.

Tropical Moist Climates (A)

Tropical moist climates extend northward and southward from the equator to about 15 to 25° of latitude. In these climates all months have average temperatures greater than 18° Celsius. Annual precipitation is greater than 1500 mm. Three minor Köppen climate types exist in the A group, and their designation is based on seasonal distribution of rainfall. Af or tropical wet is a tropical climate where precipitation occurs all year long. Monthly temperature variations in this climate are less than 3° Celsius. Because of intense surface heating and high humidity, cumulus and cumulonimbus clouds form early in the afternoons almost every day. Daily highs are about 32° Celsius, while night time temperatures average 22° Celsius. Am is a tropical monsoon climate. Annual rainfall is equal to or greater than Af, but most of the precipitation falls in the 7 to 9 hottest months. During the dry season very little rainfall occurs. The tropical wet and dry or savanna (Aw) has an extended dry season during winter. Precipitation during the wet season is usually less than 1000 millimeters, and only during the summer season.

Dry Climates (B)

The most obvious climatic feature of this climate is that potential evaporation and transpiration exceed precipitation. These climates extend from 20 - 35° North and South of the equator and in large continental regions of the mid-latitudes often surrounded by mountains. Minor types of this climate include:

  • BW - dry arid (desert) is a true desert climate. It covers 12% of the Earth's land surface and is dominated by xerophytic vegetation. The additional letters h and k are used generally to distinguish whether the dry arid climate is found in the subtropics or in the mid-latitudes, respectively.
  • BS - dry semiarid (steppe). Is a grassland climate that covers 14% of the Earth's land surface. It receives more precipitation than the BW either from the intertropical convergence zone or from mid-latitude cyclones. Once again, the additional letters h and k are used generally to distinguish whether the dry semiarid climate is found in the subtropics or in the mid-latitudes, respectively.
 

Moist Subtropical Mid-Latitude Climates (C)

This climate generally has warm and humid summers with mild winters. Its extent is from 30 to 50° of latitude mainly on the eastern and western borders of most continents. During the winter, the main weather feature is the mid-latitude cyclone. Convective thunderstorms dominate summer months. Three minor types exist: Cfa - humid subtropical; Cs - Mediterranean; and Cfb - marine. The humid subtropical climate (Cfa) has hot muggy summers and frequent thunderstorms. Winters are mild and precipitation during this season comes from mid-latitude cyclones. A good example of a Cfa climate is the southeastern USA. Cfb marine climates are found on the western coasts of continents. They have a humid climate with short dry summer. Heavy precipitation occurs during the mild winters because of the continuous presence of mid-latitude cyclones. Mediterranean climates (Cs) receive rain primarily during winter season from the mid-latitude cyclone. Extreme summer aridity is caused by the sinking air of the subtropical highs and may exist for up to 5 months. Locations in North America are from Portland, Oregon to all of California.

Moist Continental Mid-latitude Climates (D)

Moist continental mid-latitude climates have warm to cool summers and cold winters. The location of these climates is pole ward of the C climates. The average temperature of the warmest month is greater than 10° Celsius, while the coldest month is less than -3° Celsius. Winters are severe with snowstorms, strong winds, and bitter cold from Continental Polar or Arctic air masses. Like the C climates there are three minor types: Dw - dry winters; Ds - dry summers; and Df - wet all seasons.

Polar Climates (E)

Polar climates have year-round cold temperatures with the warmest month less than 10° Celsius. Polar climates are found on the northern coastal areas of North America, Europe, Asia, and on the landmasses of Greenland and Antarctica. Two minor climate types exist. ET or polar tundra is a climate where the soil is permanently frozen to depths of hundreds of meters, a condition known as permafrost. Vegetation is dominated by mosses, lichens, dwarf trees and scattered woody shrubs. EF or polar ice caps has a surface that is permanently covered with snow and ice.

Factors Influencing the World Climatic Regions

So far in this online textbook we have discovered that the climate of a particular place is the function of a number of factors. These factors include:

1) Latitude and its influence on solar radiation received.
2) Air mass influences.
3) Location of global high and low pressure zones. 4) Heat exchange from ocean currents. 5) Distribution of mountain barriers. 6) Pattern of prevailing winds. 7) Distribution of land and sea.

8) Altitude.

At a macro-level, the first three factors are most important in influencing a region's climate. The animated graphic below provides us with a generalized model of the Earth's annual climatic variations. It also describes the latitudinal effects of these top three factors through the following climatic features:

  • Relative annual latitudinal location of the overhead Sun at solar noon.
  • Intertropical convergence zone and its area of uplift, cloud development and precipitation.
  • Subtropical high pressure zone and its associated descending air currents and clear skies.
  • Polar front and its area of uplift, cloud development and precipitation.
  • Polar vortex and its associated descending air currents and clear skies.
  • Relative location of tropical/subtropical (red) and polar (light blue) air masses.

In the animation we can see that the intertropical convergence zone, the subtropical high pressure zone, polar front and the position of tropical/subtropical and polar air masses all move in response to the seasonal movements of the Sun. It is important to understand this concept because of its climatic ramifications for locations on the globe. The type of climate that a location experiences is to a large extent a function of seasonal migration of these weather features. For example, a location at 15° North latitude is influenced by the subtropical high pressure zone during winter solstice and by the intertropical convergence zone during the summer solstice. Another location, at 60° North latitude, would be influenced by polar air masses during the winter solstice, the polar front during the equinoxes, and by subtropical air masses and the subtropical high pressure zone during the summer solstice.

When studying about the Earth's Climatic Regions as described below, use this animation (Figure 7v-1) as a guide to understanding the large scale climatic processes that produce each location's particular climate.

Figure 7v-1: Solar influence on the movement of the Earth's global circulation patterns.

Climatic Region Descriptions

The following discussion organizes the climatic regions of the world into eight different groups. Categorization of these climates is based on their Köppen classification and seasonal dominance of air masses.

Tropical Wet

  • Köppen Classification - Af.
  • Dominated by Maritime Tropical air masses all year long.

The tropical wet climate is characterized by somewhat consistent daily high temperatures ranging between 20 to 30° Celsius. The monthly temperature averages vary from 24 to 30° Celsius. Annual range of monthly temperatures is about 3° Celsius. It has reasonably uniform precipitation all year round, and total rainfall over 2000 millimeters or greater.

The region experiencing this climate lies within the effects of the intertropical convergence zone all year long. Convergence and high maritime humidity creates cumulus clouds and thunderstorms almost daily.

Af - Andagoya, Columbia 5° N , Elevation: 65 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  27  27  28  28  27  27  27  27  27  27  27  27  27
Precip. mm  554  519  557  620  655  655  572  574  561  563  563  512  6905

Figure 7v-2: Mean monthly temperature and precipitation values for Andagoya, Columbia.

Af - Iquitos, Peru 4° S , Elevation: 104 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  27  27  27  27  26  26  25  27  27  27  27  27  26
Precip. mm  256  276  349  306  271  199  165  157  191  214  244  217  2845

Figure 7v-3: Mean monthly temperature and precipitation values for Iquitos, Peru.

Tropical Wet and Dry

  • Köppen Classification - Aw and Am.
  • Maritime Tropical air masses high Sun season and Continental Tropical air masses low Sun season.

This climate has distinct wet/dry periods. The seasonal pattern of moisture is due to the migration of the intertropical convergence zone. The wet season is synchronous with the high Sun and the presence of the convergence zone. The dry season is a result of the more stable air developing from the subsidence associated with the presence of the subtropical high zone during the low Sun season.

During the rainy season, the climate of this location is similar to the tropical wet climate: warm, humid, and has frequent thunderstorms. During the dry season more or less semi-desert conditions prevail. Some regions may experience intensification of rainfall because of monsoon development and orographic uplift.

Aw - Calcutta, India 22.5° N , Elevation: 6 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  20  23  28  30  31  30  29  29  30  28  24  21  27
Precip. mm  13  24  27  43  121  259  301  306  290  160  35  3  1582

Figure 7v-4: Mean monthly temperature and precipitation values for Calcutta, India.

Aw - Cuiaba, Brazil 13.5° S , Elevation: 165 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  27  27  27  27  26  24  24  26  28  28  28  27  27
Precip. mm  216  198  232  116  52  13  9  12  37  130  165  195  1375

Figure 7v-5: Mean monthly temperature and precipitation values for Cuiaba, Brazil.

Aw - Darwin, Australia 12.5° S , Elevation: 27 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  28  28  28  28  27  25  25  26  28  29  29  29  28
Precip. mm  341  338  274  121  9  1  2  5  17  66  156  233  1563

Figure 7v-6: Mean monthly temperature and precipitation values for Darwin, Australia.

Am - Mangalore, India 13° N , Elevation: 22 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  27  27  28  29  29  27  26  26  26  27  27  27  27
Precip. mm  5  2  9  40  233  982  1059  577  267  206  71  18  3467

Figure 7v-7: Mean monthly temperature and precipitation values for Mangalore, India.

Subtropical Desert and Steppe

  • Köppen Classification - BWh and BSh.
  • Dominated by Continental Tropical air masses all year.

This climate type covers 12 percent of all land area on the continents. The heart of the tropical desert climate is found near the tropics of Cancer and Capricorn, usually toward the western side of the continents. Regions with this climate have the following common climatic characteristics:

  • low relative humidity and cloud cover.
  • low frequency and amount of precipitation.
  • high mean annual temperature.
  • high monthly temperatures.
  • high diurnal temperature ranges.
  • high wind velocities.

The tropical desert climate is influenced by upper air stability and subsidence which is the result of the presence of the subtropical high pressure zone. Relative humidity is normally low, averaging 10 to 30 percent in interior locations. Precipitation is very low in quantity and very infrequent in distribution, both temporally and spatially.

Temperature varies greatly both diurnally and annually. The highest average monthly temperatures on the Earth are found in the tropical desert. They range between 29 to 35° Celsius. Winter monthly temperatures can be 15 to 25° cooler than summer temperatures. This climate also has extreme diurnal ranges of temperature. The average diurnal range is from 14 to 25° Celsius.

BWh - Berbera, Somalia 10.5° N , Elevation: 8 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  25  26  27  29  32  37  37  37  34  29  26  26  30
Precip. mm  8  2  5  12  8  1  1  2  1  2  5  5  52

Figure 7v-8: Mean monthly temperature and precipitation values for Berbera, Somalia.

BWh - Alice Springs, Australia 23.5° S , Elevation: 579 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  28  28  25  20  15  12  12  14  18  23  26  27  21
Precip. mm  44  34  28  10  15  13  7  8  7  18  29  39  252

Figure 7v-9: Mean monthly temperature and precipitation values for Alice Springs, Australia.

BSh - Monterrey, Mexico 26° N , Elevation: 512 m

   Jan.  Feb.  Mar.  Apr.  May  June  July  Aug.  Sept.  Oct.  Nov.  Dec.  Year
Temp. ° C  14  17  20  23  26  27  28  28  26  22  18  15  22
Precip. mm  18  23  16  29  40  68  62  151  78  26  29  20  606

Figure 7v-10: Mean monthly temperature and precipitation values for Monterrey, Mexico.

Mid-Latitude Desert and Steppe

  • Köppen Classification - BWk and BSk.
  • Dominated by Continental Tropical air masses during summer and Continental Polar in winter.

Última postagem

Tag