How The Old Farmer's Almanac Predicts The Weather

How The Old Farmer's Almanac Makes Long Range Predictions

August 16, 2021
Weather Conditions

Every year, folks ask us … “How does The Old Farmer’s Almanac predict the weather?” As America’s oldest weather forecaster, we specialize in predicting long-range weather, using a unique, age-old formula that’s traditionally 80% accurate. 

Some think our 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. Have you ever looked inside a persimmon seed? It 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, repeating 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 the creation of weather forecasts in our annual almanac.

We’ve Predicted the Weather Since George Washington Was President

Our weather forecast methodology stems from a secret formula that was devised by our founder, Robert B. Thomas, in 1792, when George Washington was president. And believe it or not, it has nothing to do acorns, apples, wooly bear caterpillars, or persimmons!

Thomas believed that weather on Earth was influenced by sunspots, which are magnetic storms on the surface of the Sun. Notes about his formula are locked in a black box in our offices in Dublin, New Hampshire.

Enjoy this humorous interview with Almanac Editor-in-Chief Jud Hale who shares the legend of the black box.


3 Disciplines in Long-Range Predictions

Over the years, we have refined and enhanced that formula with state-of-the-art technology and modern scientific calculations. We employ three scientific disciplines to make our long-range predictions:

  • solar science, the study of sunspots and other solar activity;
  • climatology, the study of prevailing weather patterns; and
  • meteorology, the study of the atmosphere.

We predict weather trends and events by comparing solar patterns and historical weather conditions with current solar activity.

Although neither we nor any other forecasters have as yet gained sufficient insight into the mysteries of the universe to predict the weather with total accuracy, our results are often very close to our traditional claim of 80 percent.


What Is “Normal” Weather?

When you read the weather predictions in this Almanac (or listen to any TV or radio forecast), you may notice the terms “normal” or “average” used to compare current traditions.

Most of us may think of the weather as what happened last year or the year prior. We look at weather versus what is typical in your area. Our forecasts emphasize temperature and precipitation deviations from averages, or normals. These are based on 30-year statistical averages prepared by government meteorological agencies and updated every 10 years. The 2022 forecasts are based on tabulations that span the period 1981 through 2010. Starting in next year’s edition (2023), our forecasts will be based on a data set ending 2020. Read about how climate normals are calculated.

The 2022 Old Famer’s Almanac is Now Available!

2022 Old Farmer's Almanac

Find 12 months of weather predictions and so much more! The 2022 Old Farmer’s Almanac is now available to order exclusively in our store and on

Stay tuned as we roll out the new 2022 edition across North America in the coming weeks!


The 2021 Old Farmer's Almanac


Reader Comments

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I don't believe your claim of 80% accuracy. You are "grading your own paper." Nevertheless, I have been reading the Almanac for many years and continue to do so. It definitely is interesting with a pleasant degree of humor. :{)>

Fascinating Read

Thank you for writing this article. I am a scientist who studies every aspect of how Geology, Weather, and Space are interconnected. I am certainly interested in working for an organization like yours and continue to gather records to predict a more accurate picture of the annual climate. Thanks for sharing!

North of Detroit Mich

I grew up on a farm 30 miles North of Detroit Mich
I have always been very Interested in the Weather
I enjoy reading every thing you Publish
Thank You


I’ve recently developed a self acuired addiction to accruing knowkedge. As nerdy as that sounds, I find myself researching a plethora of different subjects in my free time just to try to gain a glimpse of all the secrets this world holds.
In today’s world, bias and subjectivity taints almost everything you read and hear. Society has become me vs you and simple facts are distorted based on the author or presenters perception. I never take anything at face value and if I’m at all able to I try to figure out the science and raw principles behind why/how something works. I admire the Almanac in its use of data to determine an outcome.
My only question is why would you not make this “formula” available to more people? Of course I see how when readily available, people could abuse and tarnish the reputation of the Almanac by making incorrect predictions, but their is also some disadvantage to the almanac by not having a more broadened analytical base. Two heads are better that one kind of thing. Just a thought, I’ve notived that sometimes my private studies have led me to hit roadblocks that state I need to pay or that I don’t have access to due to secrecy. I hate that about this world. Knowledge is power, but it should be available to all those who seek it. Thanks for your time, and I respect your team’s accuracy and dedication!

the Almanac formula

The Editors's picture

Thanks for your message. The “formula” is not so much mathematical or otherwise linearly readable; it’s a matter of interpretation. We acknowledge that we use three scientific disciplines in making our weather forecasts: solar science, in particular the sunspots; climatology, the study of prevailing conditions over time; and meteorology, the study of the atmosphere. Our meteorologist “interprets” recent and current solar activity, compares it to similar periods, and considers the various global weather phenomena (e.g., oscillations, jet stream, etc.)—as well as current trends in greenhouse gases—and makes his predictions. He does not make proclamations. We do not expect to be 100% accurate; our historic average is 80% accurate. Others could take the same information (it is public) and come up with different conclusions. We have one meteorologist at a time and we put our trust in him. Two heads are better than one for some matters, but sometimes two leads to three (to break a tie) and before you know it, you’ve got a committee. We’ll stick with our one.

With chemtrails and weather

With chemtrails and weather control, do you get their flight/spraying information from them? I am amazed at your accuracy even with the sun being hazed, clouds/ blue sky covered by trails.

My grandpa used the FA every

My grandpa used the FA every year to plan when to start seeds and when to plant his garden and it was correct virtually every time. I use the FA to get a glimpse of what to expect for the weather for outdoor activities, and yes it is correct.

I'll never forget this. When

I'll never forget this. When I was a kid, I would go see my Dad every weekend in the mountains of New Mexico. We were looking through The Farmers Almanac on a Friday and it said it was going to snow on Saturday. What makes this incredible is it did snow that Saturday. You might think "how is that incredible, you were in the mountains". It was May 4th.

Great comments. I've heard

Great comments. I've heard of the Almanac but have yet to try it. I'm really looking forward to learning more.

It doesn't matter what time

It doesn't matter what time of year it is, there can always be snow on mountains tall enough. The higher up you go, the less dense the air, therefore the less heat it can hold. Even Hawaii, where it's warm year round, has a mountain which occasionally gets snow because it's high enough up that the temp can drop into the 30's.

If they were in the Mountains

If they were in the Mountains and it was already
snowing then no it wouldn't be remarkable, but the fact that it wasn't snowing and it predicted the exact day it would start is pretty good. Even in the mountains!

how we PREDICT weather

i like that there is alot of imformation

I become a big fan for

I become a big fan for Almanac after their prediction of super bowl 2014 snow strom was made almost 6 months back, yes they were off by one day, but it's incredible to predict something of that magnitude 6 months in advance. I am an astrologer too, and I was happy to know they use a bit of Astrology in their predictions. I wonder if they predict just for US or other countries too.

Thank you for the kind words,

The Editors's picture

Thank you for the kind words, PPT!   Yes, you "get" the Almanac. Our predictions are very long-range not local daily forecasts but they tend to be on trend. We cover the U.S. regions and also have a Canadian edition that focuses on the five most populous regions. Last winter, we were correct in our forecast temperature from the previous winter in four out of the five regions, for an 80% accuracy rate, missing only in Atlantic Canada.

And I have the biggest laugh

And I have the biggest laugh when I read that your predictions are 80 % accurate. Secret formula? Now that's laughable, again. Last winter was supposed to be a mild one, now it's going go be cold. I never believe you guys and I am not going to start now,

Do you even read the Almanac?

Do you even read the Almanac? Last winter, they predicted a much colder-than-average season across most of the country and that's what occurred. And why would you make fun of folks on their own web site? If you don't have something nice to say, don't say it. Move on if you're not a fan.

Well said Mr. Wilson!

Well said Mr. Wilson! @georgewilson

I agree George. I buy the

I agree George. I buy the farmers almanac every year. I have friends that are farmers and they plant according to the farmers almanac too.
I guess no matter what, there are going to be non believers with negative words

So don't read them. Perhaps

So don't read them. Perhaps watch one of those mindless TV talk shows or Reality Shows. Whatever the case, do not make your life more complicated by reading the weather predictions. I am sure one of those airhead weather persons on local tv have it better. LOL Eat your Humus and wheat germ and have a nice day!

Liz, It is "Better to remain


It is "Better to remain silent and be thought a fool than to speak out and remove all doubt."

Abraham Lincoln

Funny place to post when you

Funny place to post when you don't listen to them LOL

Where do you live, Miami?

Where do you live, Miami? Last winter WAS mild, and we're not even in winter and it is bone-chillingly cold.


This article expains about

This article expains about Almanac's long term forcasts I have always wondered about. Great articles. Mike 10/2012

hello everyone im from

hello everyone im from wilmington nc and iv always watch the weather channel when the weather turns cold hopeing for snow i always look up to see a sundog in the sky knowing its going to rain or snow i perfer snow myself

I am 65 and has been a

I am 65 and has been a weather buff all my life and I find that most of the folklores are true. My theory behind this is, that nature makes it easy for the animals to make there preditions for seasons.

I live in the south and I

I live in the south and I find this to be true.
When your windows sweat on the outside its hot and humid.
When your windows sweat on the inside it cold out.

There are always an

There are always an interesting and newly informative article found in these pages, and I keep forwarding them out. I think is great. My question is, why are their so many different covers for the same almanac? I think we should stay with the yellow cover always.

Hi, ScaperRon. The Old

The Editors's picture

Hi, ScaperRon. The Old Farmer's Almanac ALWAYS has a yellow cover, with the year in red type. (See the upper left hand corner of our web page for a visual.) There are many different almanacs out there, but we are the original Farmer's Almanac, founded in 1792 and published every year since.

I love this website. I was

I love this website. I was born on a full moon September 18, 1967 and i didn't know that before I found this wonderful website. I have always wondered why I had a fascination with moon as far back as i could remember when I was about 3 or 4. Thank you !

Hi Elena, how did you find

Hi Elena, how did you find that out? This is being written to you almost 2 years later--but I just found this site, saw your comment on an article and have been searching this site to enter my own birth date so I too can find out the weather on the day I was born. Do you remember how you found that out?