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How We Predict the Weather

Robert B. Thomas (1766-1846)

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How does The Old Farmer's Almanac predict the weather?

We derive our weather forecasts from a secret formula that was devised by the founder of this Almanac, Robert B. Thomas, in 1792. Thomas believed that weather on Earth was influenced by sunspots, which are magnetic storms on the surface of the Sun.

Notes about that formula are locked in a black box in our offices in Dublin, New Hampshire. (Yes, that's a photo of the unassuming black box below.)

The Almanac's secret black box

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.

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 ten years. The most recent tabulations span the period 1981 through 2010.

We believe that nothing in the universe happens haphazardly, that there is a cause-and-effect pattern to all phenomena. However, 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 almost always very close to our traditional claim of 80 percent.

Pick up a copy of The Old Farmer's Almanac here.

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With chemtrails and weather

By C. J

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

By CoryCamp111

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

By Divereric

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.

It doesn't matter what time

By Adamasdfgh

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.

Great comments. I've heard

By Ron Ash

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

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,

By Almanac Staff

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

By Liz M.

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,

Where do you live, Miami?

By Biff Tannen

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


Funny place to post when you

By russell live

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

Liz, It is "Better to remain

By Truth


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

Abraham Lincoln

So don't read them. Perhaps

By paradigmshift

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!

Do you even read the Almanac?

By georgewilson

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.

I agree George. I buy the

By Sue A

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

Well said Mr. Wilson!

By Ione Indigo

Well said Mr. Wilson! @georgewilson

This article expains about

By Mike S.

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

hello everyone im from

By jerry sauls

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

By fdollar

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

By fdollar

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

By ScaperRon

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

By Almanac Staff

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

By Elena Waters

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 almanac.com !

I am only 11 but i love this

By into

I am only 11 but i love this amazing site lol

Hi Elena, how did you find

By lboucher

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?

Hi, there is a Moon calendar

By Catherine Boeckmann

Hi, there is a Moon calendar that goes back to 1902 on this site! See: http://www.almanac.com/moon/calendar
Also, there is a Weather History tool though it may not go back far enough! http://www.almanac.com/weather/history

I am so glad that I found

By pearflower

I am so glad that I found this website! I grew up in KS(am now 52) and am usually right on whenever I think a thunderstorm is headed our way. I love to watch the weather patterns, and it helps whenever a tornado approaches. Thanks for the great info!!

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