Continental climates often have a significant annual variation in temperature, They tend to occur in the middle latitudes, within large landmasses where prevailing winds blow overland bringing some precipitation, and temperatures are not moderated by bodies of water such as oceans or seas unlike temperate climates. Continental climates occur mostly in the Northern Hemisphere, which has the kind of large landmasses on temperate latitudes required for this type of climate to develop. Most of northern and northeastern China, eastern and southeastern Europe, Western and north western Iran, central and southeastern Canada, and the central and northeastern United States have this type of climate. Continentality is a measure of the degree to which a region experiences this type of climate.
In continental climates, precipitation tends to be moderate in amount, concentrated mostly in the warmer months. Only a few areas—in the mountains of the Pacific Northwest of North America and in Iran, northern Iraq, adjacent Turkey, Afghanistan, Pakistan, and Central Asia—show a winter maximum in precipitation. A portion of the annual precipitation falls as snowfall, and snow often remains on the ground for more than a month. Summers in continental climates can feature thunderstorms and frequent hot temperatures; however, summer weather is somewhat more stable than winter weather.