While the global conveyor belt and midlatitude cyclones redistribute heat and modulate climate on a much larger scale, there are very localized regions in the world that have climates of their own based off of the terrain, proximity to the ocean, and local water sources. For example, in San Francisco, on a summer day, it is not uncommon to see the shoreline bombarded with by fog and drizzle on the Pacific Ocean side with temperatures in the upper-50s. While just across the bay, it can be above 100 degrees with sunny skies. This is an example of a microclimate, which is a sharp disparity in temperature, cloud cover, and precipitation due to the proximity of the ocean or complex mountainous terrain. Along the west coast, typically storm systems can hit San Francisco, especially during the wet season in the winter months from November through March, which comes from the Pacific Ocean. These storms channel plumes of water vapor from the tropics. These long, narrow bands of concentrated water vapor in the atmosphere that transports huge amounts of moisture are called Atmospheric Rivers or The Pineapple Express. While these events denote most of the west's annual snowpack and rainfall, if they become too intense, it can lead to heavy rainfall and flooding, mudslides and landslides, and increased runoff. While they are most common along the west coast, these atmospheric rivers can also occur from the Gulf of Mexico. 

One primary example of a microclimate is the rain shadow effect, which forms due to mountainous terrain. The rain shadow effect is the process where mountains force moist air to rise, cool, and drop its precipitation on the windward side; leaving the leeward side warm, dry, and often desert-like. This creates dramatic climate contrasts over short distances, such as lush forests on one side and arid valleys on the other. Essentially, prevailing wind carries moist air from the oceans or large lakes toward the land. When this air encounters a mountain, it is forced upward known as orographic lift. As it rises, the air expands and cools, causing water vapor to condense into clouds, release latent heat into the atmosphere, and form precipitation. The windward side of the mountain becomes wet, cool, and vegetated. On the contrary, on the leeward side of the mountain, after losing most of its moisture, the air crosses the peak and sinks down the leeward slopes. Sinking air compresses and warms, which inhibits cloud formation. The result is a dry, warm region knwon as the rain shadow. Therefore, mountains act as a physical barrier, stripping moisture from air masses. 

An important concept of climate is temperature, and most meteorologists often refer to the average low and high temperatures when comparing it to new record low or high temperatures. The Diurnal Temperature Range explains how far the gap is between a low and high temperature throughout a given year and is entirely dependent on location. For example, in San Diego, California, throughout the year, the high and low temperatures are only 10-degrees apart throughout the entire year. Whereas in Topeka, Kansas, the temperature range is 20 degrees. Why is this? Well, it's because Topeka, Kansas is in the middle of North America while San Diego is along the California coast, in proximity to near water. This is because as mentioned before, water has a higher heat capacity, the amount of energy required to raise the temperature of an object 1 degree Celsius. Therefore, in the summer, the land heats up much faster while the Pacific Ocean is still cool thanks to the cold California current. Onshore wind helps cool the land close to the ocean down whereas further inland, that cool air becomes hot, dry desert air in the valleys. In the winter, the water would act to keep the coast warmer since it takes longer for the water to cool down. Since Topeka, Kansas is in the middle of land and is not near any source of water, the air has a lower heat capacity, and therefore heats and cools much faster and causes wider temperature swings. This is why many world deserts tend to have very large diurnal temperature ranges with cold nights and hot days since the air is so dry.