A steppe climate is found in the middle of continents and in the lee of high mountains. The mountains block moist air from oceans or tropical climates from reaching the steppe. There is not enough precipitation for trees to grow except by rivers. The plants have adapted to these drought conditions by being small and growing extensive root systems. Animals have adapted by burrowing into the ground to stay cool or warm, and to find protection on the open plains of the steppe.
The temperature between summer and winter varies a lot. Summer temperatures of the steppe aren't much different from the dry savanna. Both are grasslands, and both can reach temperatures of 104° F, and have heavy thunderstorms. In the winter, however, there are no clouds to keep heat from escaping into the upper atmosphere. The land gets colder and colder. Winter temperatures of -40° F are not uncommon. There are no trees to block the wind, so it howls. The combination of low temperatures and dry winds make it a very harsh place to live.
The Steppe climate tends to go in cycles where there may be 10 years or more of good rains followed by as many years of drought. In order to be able to cope with this climate, people used to be nomadic. They would move to where the water supply was best. Now they drill deep wells and have created irrigation systems. The climate is still too harsh for large cities and industries to develop there.
The Steppe climate comes under Köppen's BS classification. The B stands for dry climates, and the S for Steppe climate. The difference between steppes and deserts are determined by the mean annual temperatures and precipitation. With a little less rain the steppe could easily turn into a desert. More rain, and it would be classified a prairie.
Bibliography:
"climate", http://curriculumvisions.com/weather/worldWeather/climates/steppe.html
Strahler, Arthur N., and Strahler, Arthur H. Elements of Physical Geography. John Wiley & Sons, 1984.