The Farmers’ Almanac boasts an 80% success rate in predicting the weather two years in advance!
Each year the Farmers' Almanac is published with long-range weather forecasts. Prediction for each can be made up to two years in advance, and the Almanac's publishing company claims it has a success rate of 80 percent!
That number varies slightly, but "our results are almost always very close to our traditional claim of 80 percent."
How do they make such accurate predictions?
They used a variation of a formula developed by the founder of the Almanac, Robert B. Thomas, in 1792! Only a few people in the world know the formula, but we do know a few of the factors it takes into account.
They look at solar science, the study of sunspots and other solar activity; climatology, the study of prevailing weather patterns; and meteorology, the study of the atmosphere.
They predict weather trends and events by comparing solar patterns and historical weather conditions with current solar activity. It's a "top secret mathematical and astronomical formula that relies on sunspot activity, tidal action, planetary position and many other factors."
"We believe that nothing in the universe happens haphazardly, that there is a cause-and-effect pattern to all phenomena," their website says.
Still, not everyone is sold on the Almanac's predictions. Independent studies that retrospectively compare the weather with the predictions have not shown them more accurate than chance. Maybe those studies were flukes, or maybe we've been getting fooled by the Almanac for 200 years!