By Kennedy Elliott and Shelly Tan January 31, 2015By Kennedy Elliott and Shelly Tan January 31, 2015Share this storyEditor's note: Our colleagues in the Graphics department had a burning question: can groundhogs really predict the weather? They ran the numbers on 250 cities over 30 years. Here's what they found out. Support our journalism. Subscribe today ArrowRightThe previous headline misstated the number of years mapped. The headline has been corrected.GiftOutlineGift ArticleToday's HeadlinesThe most important news stories of the day, curated by Post editors and delivered every morning.