Why does the Northern Hemisphere experience a greater annual range of temperature than the Southern Hemisphere?

You may think that weather is virtually the same worldwide, but on the contrary, the type of weather you experience is somewhat unique to which part of the world you live in. Events like tornadoes, which are commonplace here in the United States, are a rarity in other countries. Storms we call "hurricanes" are known by another name in the world's far oceans. And perhaps one of the most well known—which season you're in depends on which hemisphere (which side, north or south, of the equator you're on)—Northern or Southern—you live in.

Why do the Northern and Southern Hemispheres see opposite seasons? We'll explore this answer, plus other ways their weather is strikingly different from the others. 

December may be ... but our neighbors in the Southern Hemisphere rarely ever see snow on Christmas (except in Antarctica) for one simple reason—December begins their summer season. 

How can this be? The reason why is the same as why we experience seasons at all—the Earth's tilt.

Our planet doesn't "sit" perfectly upright, but rather, leans 23.5° from its axis (the imaginary vertical line through Earth's center which points toward the North Star). As you may know, this tilt is what gives us the seasons. It also orients the Northern and Southern Hemispheres in opposite directions so that whenever one points its innermost toward the sun, the other aims away from the sun.

In the Northern Hemisphere, the Coriolis force, a which deflects to the right, gives hurricanes their signature counter-clockwise spin. but spin counter-clockwise. Because Earth rotates to the east, all free-moving objects such as wind, low-pressure areas, and hurricanes are deflected to the right of their path of motion in the Northern Hemisphere and to the left in the Southern Hemi.

There's a misconception that because of the Coriolis force, even water in bathrooms spirals clockwise down the drain—but this isn't true! Toilet water isn't of a large enough scale for the Coriolis force so its effects on it are negligible. 

Take a moment to compare a map or globe of the Northern and Southern Hemispheres...what do you notice? That's right! There's more landmass north of the equator and more ocean to its south. And since we know that water warms and cools more slowly than land does, we can guess that the Southern Hemisphere has a milder climate than the Northern Hemisphere,

In Earth's present-day climate, the annually-averaged surface air temperature in the Northern Hemisphere (NH) is ? 1.5°C higher than in the Southern Hemisphere (SH). This interhemispheric temperature difference has been known for a long time, and scientists have pondered over its origin for centuries. Frequently suggested causes include differences in seasonal insolation, the larger area of tropical land in the NH, albedo differences between the Earth's polar regions, and northward heat transport by the ocean circulation. Here we systematically assess the origin of the interhemispheric temperature difference. To this end we combine an analysis of climatological data as well as observations of the Earth's energy budget with simulations using a coupled climate model. We find that the interhemispheric temperature difference is predominantly caused by meridional heat transport in the oceans, with an additional contribution from the albedo difference between Antarctica and the Arctic.

Global climate is the largest spatial scale.   We are concerned with the global scale when we refer to the climate of the globe, its hemispheres, and differences between land and oceans. Energy input from the sun is largely responsible for our global climate.   The solar gain is defined by the orbit of Earth around the sun and determines things like the length of seasons.   The distribution of land and ocean is another import influence on the climatic characteristics of the Earth.   Contrasting the climate of the Northern Hemisphere, which is approximately 39% land, with the Southern Hemisphere, which only has 19% land, demonstrates this (see the table below).   The yearly average temperature of the Northern Hemisphere is approximately 15.2C, while that of the Southern Hemisphere is 13.3C. The presence of the water reduces the annual average temperature.   The land reduces the winter average temperature while increasing the average temperature during summer.   As a result, the annual amplitude of the seasonal temperature is nearly twice as great for the Northern Hemisphere. The Northern Hemisphere has a large variation in the monthly mean temperature. The land absorbs and loses heat faster than the water.   Over land, the heat is distributed over a thin layer, while conduction, convection and currents mix the energy over a fairly thick layer of water. Soil, and the air near it, therefore follow radiation gains more closely than water.   For this reason, continental climates have a wider temperature variation.   We observed this in Chapter 3 by comparing the seasonal cycles of temperatures for different regions of the globe.

The average temperatures of the Northern Hemisphere and Southern Hemisphere for winter, summer and the year.   The Annual Range is give as well as the differences between the Hemispheres.   Differences between the Hemispheres are caused by the differences in the distribution of land and water.