Why are there seasons on Earth?

Earth has seasons because our planet travels around the sun while tilted on its axis. When your half of Earth leans sunward, daylight arrives more directly and lasts longer, so it is summer. When it leans away, the light is lower, spread out, and shorter, so it is winter.

That means July can bring sandals in the Northern Hemisphere while places such as Australia are in their cold months. Twice each year, during an equinox, neither half gets the stronger share, and many places notice day and night coming closer to equal length.