Surely a study has been done, comparing the farmer’s almanac’s long range weather forecasts with historical data for the same period of time.
Does it really do better than chance? Or am I just as well off saying that the fourth of July next year might be… uh… a standard dev chillier than normal?
The publication claims 80 percent but what does that really mean? One study that I know of compared day-today weather reports with the Almanac over a fifty-year period. The accuracy on a day-to-day basis was about 50 percent. Read about it here. If the almanac predicts a 3-day sunny period and it ends up raining on one of those days, was the prediciton accurate? It’s a judgement call.