The signs of the coming of spring include firstly the sight of Robins. It is believed that the sight and singing of the Robins is considered arrival of spring by many in the US. Secondly, the winter is not yet over but the blooming of Daffodils first of all flowers is indication of the spring. As the air gets warmer the flowers bud and new leaves start growing on trees since the days also begin to get longer providing much warmth which also an indicator of the spring.
Without the axial tilt of our Earth, firstly, the Sun would have remained above the equator (Equinox) forever but fortunately due to the tilt we get equinoxes twice a year and not forever. Moreover, the temperature and precipitation levels would not vary much and the equator would remain always warm and the poles always cold. Secondly, due to the tilt as the Earth orbits around the Sun and with changes in solstices we get variety of the seasons which would have been impossible otherwise.
