The Dublin, New Hampshire based publishers of the Old Farmer's Almanac have placed on their website a full year forecast for New England and eastern New York from November 2008 to October 2009:
In contrast, the Farmer's Almanac, located since 1955 in Lewiston, Maine, provides only a December and January forecast on its website for an area that runs from Maine to New York to Virginia.
The predictions of the two are prepared as much as two years in advance and each uses different, secret calculations that take into consideration such factors as the position of the earth and the other planets in space, solar conditions (sun spots, etc.), past weather patterns, tidal action, and the condition of the atmosphere.
Many people swear by the long range forecasts of the almanacs while others point to inaccuracies in past forecasts as evidence that long range forecasts are worthless. Some base this opinion on the fact that even the government's NOAA five day forecasts are often inaccurate.
For more than 50 years, my paternal grandfather, a skeptic in many matters, would purchase a copy of both almanacs, copy the forecasts of each to paper, and then write the actual weather beside the prediction. He gained much amusement from this, and told me that, for Portland, the forecasts where no better what he termed "using a finger in the wind in December for July weather."
By contrast, I talked last week to a man in central Maine who has done the same comparison since the 1980s and swears by the accuracy of the long range predictions.
For me, I take my weather day by day, and hour by hour.
If it looks like rain, I prepare accordingly; if it is hot, I wear fewer clothes; if we are on our boat, I keep NOAA marine weather on the VHF at all times since what NOAA said this morning may not be what is happening now.