Low latitude and high altitude, why is the temperature in annual range small?

The latitude is low, the solar radiation is strong, the height of the sun changes little at noon, and the variation range of the length of day and night is also small, so the annual variation of solar radiation is small, so the annual variation range of temperature is small. The higher the altitude, the smaller the weather changes, reducing the influence of weather on temperature. Consider two factors, low latitude, high altitude and low temperature throughout the year.