How The Old Farmer's Almanac Predicts The Weather (2024)

Read on to learn about our unique, age-old formula that’s based on three scientific disciplines, and to ponder these key questions:

• What’s normalweather?
• How does climate change factor into ourforecasts?
• What role does weather loreplay?

New! Read about our 2023—2024 Winter Forecast!

A Secret WeatherFormula

The Old Farmer’s Almanac has predicted the weather since our founding in 1792—when George Washington was president and actively farming at Mount Vernon (Fun fact: One of Washington’s greatest preoccupations during his agricultural career was to eschew single crop farming; in 1785-86, his diaries mention planting barley, clover, corn, carrots, cabbage, flax, millet, oats, peas, potatoes, spelt, turnips, and wheat, among othercrops.)

Our weather forecast methodology stems from a formula devised by our founder, Robert B. Thomas. Thomas believed the Earth’s weather was influenced by sunspots, which are magnetic storms on the surface of the Sun, and this factored heavily in hisforecasts.

Over the years, we have refined and enhanced Thomas’s formula with state-of-the-art technology and modernscience.

We Use 3 Disciplines in Long-RangePredictions

We predict weather trends and events by comparing solar patterns and historical weather conditions with current solar activity. We employ three disciplines to make our long-rangepredictions:

• solar science, the study of sunspots and other solaractivity;
• climatology, the study of prevailing weatherpatterns;
• and meteorology, the study of theatmosphere.

Like all forecasters, we have not yet gained sufficient insight into the mysteries of the universe to predict the weather with total accuracy, though our results are often very close to our traditional claim of 80percent.

What Is “Normal”Weather?

The weather predictions in our almanac (and any other forecast for that matter) compare temperature and precipitation levels to “normal.” Our forecasts consider normal to be the 30-yearaverage.

Every 10 years, the National Center for Environmental Information calculates a new set of normal temperatures for the US based on updated 30-year averages. Starting with the 2023 edition of The Old Farmer’s Almanac, the long-range predictions are based on the 30-year time frame from 1991 to 2020 (previously, data was drawn from 1981 to2010).

Environment Canada is expected to release their new “normal” data in the fall of 2024, which will provide more insight into North Americantrends.

The recalibrated data for the US shows that warming is widespread, but not uniform. Warmer temperatures are not occurring everywhere at the same time of year, either. An example is how the first half of the year has been cooler than normal on average in the north-central U.S. over the past decade. As for precipitation, the eastern regions of the U.S. are now generally wetter than in the past, and intense rain events are morecommon.

Read more about how our climate normals are calculated.

How Does Climate Change Factor into OurForecasts?

Climate change is factored into our long-range weather forecasting, especially when it comes to temperatures. We make predictions based partly on historical data, then adjust temperature predictions to be warmer, but not uniformly: polar regions are warming faster than lower latitudes over the past severaldecades.

Overall, there are fewer colder winters than there were 50 years ago, and it’s rarer to get prolonged cold; we still see extreme cold, and even very cold months, yet less and less are we seeing—and forecasting—multiple consecutive weeks of temperatures staying solidly 5 to 6 degrees belowaverage.

In addition, there are geographic pockets where seasons, and temperatures, lag: the Canadian Prairies and Great Lakes are experiencing more winter “hangovers”—when winter weather is more pronounced later in the season, such as February and March, and intoApril.

Likewise, there’s a summer hangover effect in the northeast and mid-Atlantic regions, with summer weather extending into September andOctober.

We also use climate signals, called teleconnections, to help make our long-range weather forecasts. These links between weather phenomena at different locations on Earth affect climate patterns spanning thousands of miles—think El Niño/La Niña. Due to climate change, teleconnections can change over time, and may not be as effective as they were in the past. We constantly monitor these teleconnections to determine their effectiveness while also looking out for new teleconnections that can develop overtime.

Tropical cyclone threats are also forecasted using historical data, and these, too, have been adjusted because there are more storms than in the past. For example, in an El Niño year, we would expect less tropical activity in the Atlantic Ocean, but by September of 2023, there had already been a greater level of activity than normal, due in part to rising sea surfacetemperatures.

What’s Lore Got to Do WithIt?

Some think our long-range forecasts are derived from folklore. According to weather lore, a long, hard winter can be predicted by lots of acorns, tough apple skins, and thick corn husks, while a mild one can be predicted by lower bees nests and thin onion skins. A persimmon seed may give you clues,too!

While we can neither confirm nor deny the reliability of this folklore, we do know that, centuries ago, folks observed such phenomena and noticed corresponding weather patterns, so at The Old Farmer’s Almanac, we allow that there just might be some truth to it! However, folklore does not figure into creating weather forecasts in our annualalmanac.

Where You Can BuyThe Old Farmer’sAlmanac

The 2024 Old Farmer’s Almanac—America’s #1 Almanac—is now available to order in classic paperback, hardcover, anddigitaleditions!

Always reliable and entertaining, this handy yellow book is a “true” Almanac—a calendar of the heavens, a time capsule of the year, and an essential reference that reads like a magazine. Always timely, topical, and distinctively “useful, with a pleasant degree of humor,” the Almanac is useful DAILY in all walks oflife.

Now in its 232nd year,The Old Farmer’s Almanacis STILL the best-selling annual in the United States and Canada, thanks to readers from coast to coast! The longest-running periodical in America (since George Washington was president!), it’s a timeless guide to daily living. With our long-standing commitment to “new, useful, and entertaining matter,” you can count on your new edition to deliver a comprehensive and trustworthy guide to2024.

Order the 2024 Almanac exclusively in our Almanac.com storeor onAmazon!