Last week, Punxsutawney Phil, the prognosticator of prognosticatorsput forth his prediction for the year: spring is coming early. Human weather forecasters might put their estimations somewhere closer to March 21, but even that won’t likely reflect the actual change in temperature. That’s because, for the most part, seasons make no sense.

Joe Hanson from It’s Okay To Be Smart dives into the topic, asking: “Why divide the year into seasons in the first place?” Well, it was once a useful tool. The word itself comes from the Latin, which means “a sowing, planting.” And long ago, it was important for farmers to have a grasp on the changing weather for planting and harvesting.

Today, the overwhelming majority of us don’t need to plan out our crops—and that’s probably a good thing, because the calendar can be pretty off. The coldest parts of the year actually begin several weeks before winter technically starts, while summer weather is known to stick around well into fall. So how did we end up with this wonky calendar? Blame the Romans.

Water has a lot to do with how quickly temperature shifts occur. Roman territory was insulated by large bodies of water, which meant that their temperatures lined up with the solstices. That simply isn’t true for everyone, and it’s hard to prescribe a single seasonal calendar to large swaths of land: not every place in a given hemisphere has the same climate factors at work.

For more on our faulty seasons, check out the video above.

Images via YouTube.