What Is an Almanac? The Book That Told You What Was Coming
By the BrainSnail editorial team. How these articles are written and checked, and how to tell us when one is wrong.
For several centuries the almanac was the most widely owned printed book after the Bible, bought annually by households that owned almost nothing else in print. It combined a calendar, astronomical tables, tide times, weather predictions, medical advice, farming guidance and whatever else the compiler thought would sell, which makes surviving copies an unusually direct record of what ordinary people wanted to know.
What was in one
The contents were standardised enough that any two almanacs from the same era look similar, and the mixture reveals what the buyer needed:
- •A calendar for the year with saints' days, feast days, legal terms, fairs and market days, which was the practical core
- •Astronomical tables giving sunrise, sunset, moon phases, eclipses and planetary positions, calculated in advance and genuinely difficult to produce
- •Tide tables for named ports, which mattered enormously to anyone shipping or travelling by coast
- •Weather predictions for the year ahead, which were not calculable and were supplied anyway
- •Astrological material, including the figure of a man surrounded by zodiac signs indicating which sign governed which part of the body, used to choose times for bloodletting and medical treatment
- •Planting and husbandry advice keyed to the moon and the season
- •Practical reference including road distances, postal rates, currency conversion, interest tables and lists of officeholders
- •Filler that became the point for many readers, including proverbs, jokes, recipes, poems and essays
Why they mattered
Before newspapers were common and cheap, the almanac was the one piece of printed information updated annually that a rural household would buy, which gave it a reach nothing else had. That reach made it commercially valuable and politically useful, and compilers used the space accordingly, inserting political commentary, religious argument and advertising into a book people were obliged to consult. The astronomical work behind them was real: calculating positions for a year ahead required skill and access to tables, and many almanac makers were practising astronomers or mathematicians. Benjamin Banneker, a free Black American mathematician and astronomer, calculated and published almanacs in the 1790s and sent a copy to Thomas Jefferson with a letter challenging him on slavery, using the book itself as evidence against claims about Black intellectual capacity. Benjamin Franklin's Poor Richard's Almanack, published under a pseudonym from 1732, became famous less for its tables than for the aphorisms he packed into the margins.
Prediction and its uses
The weather predictions were the least defensible content and frequently the main selling point, and the way compilers handled that is instructive. Predictions were hedged, spread across ranges of dates and written in language that could match a variety of outcomes, which is a technique any reader of horoscopes will recognise. Jonathan Swift attacked the practice memorably in 1708, publishing under the name Isaac Bickerstaff a set of predictions including the precise date of the death of the almanac maker John Partridge, then publishing an account of that death when the day arrived, and continuing to insist Partridge was dead while Partridge protested that he was not. The episode is remembered as a satire on astrological prediction and also demonstrates how seriously the genre was taken. Several long-running almanacs still publish weather forecasts a year ahead using undisclosed methods and claim high accuracy, and independent assessments have generally found their performance close to chance.
What became of them
Almanacs declined as their functions were taken over by other publications and institutions. Newspapers supplied timely information daily rather than annually. Meteorological services produced forecasts based on observation and physics. Nautical almanacs became specialised official publications, with the British one first issued in 1767 specifically to support the lunar distance method of finding longitude at sea, and equivalents are still published annually for celestial navigation. General reference moved into yearbooks and encyclopedias. A handful of consumer almanacs survive with long continuous runs, sustained by nostalgia, gardening advice and the weather claims. The historical value of the discarded ones has risen considerably, since almanacs were bought by people who left no other written trace, and surviving copies are frequently annotated with births, deaths, harvests, prices and weather actually observed, which makes a well-used almanac a rare first-hand record of an ordinary life.
The takeaway
An almanac combined a calendar, astronomical and tide tables, weather predictions, medical and farming advice and practical reference, and was the most widely owned printed book after the Bible in several countries. The astronomical work was genuinely skilled while the weather predictions were guesswork hedged into plausibility, which Swift satirised in 1708 by predicting a rival compiler's death. Newspapers, meteorology and official nautical tables absorbed its functions, and annotated surviving copies now record ordinary lives.