Temperate Grassland  Temperatures in the winter often fall below –10ºC, while summers may be very hot, approaching 30ºC, and summer droughts are not uncommon.  Annual rainfall is generally between 25 and 100 cm, too low to support a forest but higher than that in deserts.  Prairie soils are among the richest in the world, having a nutrient content much greater than that of a typical forest soil.