With the exception of Antarctica, wine grapes are found on all the continents. However, there are important considerations about their location, and all the winegrowing regions have some specific things in common.
Looking at a map of the world's winemaking regions, it becomes apparent that latitude and water are common factors and "not too cold, not too hot" is one of the rules. Wine grapes like to live where there are four seasons, but where the summer's heat is not accompanied by heavy rainfall and the winter's cold is not accompanied by too deep a freeze. All the great wine regions allow the vine to complete the cycle of full dormancy to vigorous reproduction. This means that the temperatures during the winter generally achieve the occasional frost - and, a little snow is not a bad thing. Summer temperatures can be quite hot, depending on the type of wine and the grape variety - a "high heat" example is Portugal's Porto wines. Summer in the Upper Douro River valley, where Porto is grown, can be exceedingly hot, but that is what makes the wine what it is. Winters there are cold enough to allow the vine to go completely dormant. Latitude plays a significant part here, since if you are too far north (or south), the sun doesn't provide enough heat energy to warm the area sufficiently to ripen the grapes.
Water is another constant. Virtually all the great wine-growing regions are near water - either oceans or rivers. Bodies of water, because of their fairly constant temperatures, help to moderate the extremes of climate. Anyone who lives near a large lake can appreciate the natural "air conditioning" that occurs when summer's heat is bearing down further inland. In Europe, it is the Atlantic Ocean and the Mediterranean Sea that are the greatest influence. But, further inland in northern Europe, the Rhine River and the Bordeaux estuaries have similar influence on the surrounding vineyards.
This combination of latitude and water-influenced temperature moderation are virtually constant. Just a cautionary note, however: altitude also plays a role here, as the Hill Country of Texas can demonstrate. Vineyards there are definitely not influenced by any major bodies of water, and land at the same latitude, but much lower elevation, would prove to be extremely hostile to wine grapes.