Explain why there are usually mild temperatures during spring and fall?

Mild temperatures during spring and fall result from the transitional nature of these seasons, where the atmosphere is balancing between the extremes of winter and summer. During spring, the sun's rays become more direct, gradually warming the Earth while still benefiting from residual cool air. Conversely, in fall, as the sun's intensity decreases, the lingering warmth from summer gradually cools, creating a temperate climate. Additionally, the tilt of the Earth's axis and changing weather patterns contribute to these moderate temperatures.