The convergence of three phenomena brings springtime to the large land masses in the temperate zones of the earth. These same conditions create the four season climate in these same areas.
The tilt of the earth coupled with its annual circuit around our resident star fuels jet streams in the northern and southern hemispheres. These masses of rapid moving air at high altitudes serve to either pull the frigid air from the poles toward the equator when that pole slants away from the sun. They drag warm air from the equator toward the poles when the tilt is toward the sun. The temperate zones are the battleground of changing weather conditions during the spring and fall of the year. Both times can bring changing and violent weather.
If the land is near enough to the ocean, these weather swings are softened by the warm water that cools and warms slower than the land it surrounds. Places like Australia, England, and other coastal and island areas have less obvious or no spring times except as a raining season. Annual and deciduous plants are replaced more by perennials. Although these places are in temperate zones, they do not have what is normally regarded as spring.
Because the jet streams flow from west to east, temperate regions must be far enough from the ocean to allow for the air to cool to winter temperatures to force dormancy in plants and some animals. As the jet stream moves toward the pole in late winter and early spring, the warm equatorial air is pulled into the temperate zones. The gradual warming coupled with increasing daylight hours serves to wake up the sleeping flora and fauna. Spring has sprung.
Spring comes to areas that are temperate, away from ocean breezes, and large enough land masses to cool air to produce winter.
