Use Your Coffee Cup to Predict Whether Rain Will Ruin Your Outdoor Shoot

Did you know that your morning cup of coffee can help you predict rain? It’s a trick used by backpackers that can come in handy you’re shooting outdoors without Internet: pour a cup of coffee and carefully watch the bubbles. Backpacker Magazine writes,

If the bubbles amass in the center, you’re in a high-pressure system, which is making the coffee’s surface convex (higher in the middle). Since bubbles are mostly air, they migrate to the highest point. It’s going to be a beautiful day. If the bubbles form a ring around the sides of the mug, you’re in a low-pressure system, making the surface concave. Rain is likely. Note: It has to be strong, brewed coffee to have enough oil to work, and the mug must have straight sides.

To make new bubbles, simply give your coffee a good stir.

(via Backpacker Magazine via Instructables via Lifehacker)

Image credit: drip by subsetsum


    I am not to sure about that one 

  • Mark J P

    I have heard this a few times now but never tried it.  Something to do with atmospheric pressure?  I’m going to try it tomorrow morning! :)

  • Tam Nguyen Photography

    Or I can just bust out my phone and read the weather forecast.

  • Richard

    Did you try this Michael? I don’t trust Backpacker magazine (ad-ridden crap) but if someone reposts something like this after trying it I guess it might be credible.

  • Felipe Carlos

    it would be difficult to read the weather forecast on your phone if you were shooting outdoors and didn’t have internet… ;)

  • MrRocking

    Does it have to be filter coffee or will instant do? How many sugars? Am allowed milk? What happens if I use a non dairy substitute?

    So many variables.

  • Titus-Armand

    So you’re in the wild without a phone and without internet, but you’ve got coffee?…

  • el_b

    This is such a cool trivia information, why is everyone bitching? Why doesn’t anyone jus t ask why this happens?

  • David

    Yes, that’s correct.  You don’t do a lot of camping, do you?

  • Titus-Armand

    I’m not sure you’ve really _camped_ if you you can afford to go in the wild without a phone. Backyard camping doesn’t count.

  • Titus-Armand

    Atmospheric pressure is why it happens.

  • Brian Utterback

     I have found a couple of references that claim that this is due to the pressure causing the coffee to either be lower at the center or higher at the center. I am sorry, but I find this extremely difficult to believe. Certainly falling pressure is an indicator of rain, but it is hardly reliable. Added to that is the idea that the pressure is changing rapidly enough to affect the shape of the surface of the coffee. Don’t believe it for a second. Either it is totally bogus or there is something else going on.

  • OSAM

    3G? or 4G?

  • Budforce

    U got it exactly backwards.

  • Dvorark

     What does your statement even mean? Coffee during camping, any kind of camping, is completely normal. You boil some water, add coffee…what’s so hard about that?

  • Michael Zhang

    Hmm. There seems to be some confusion online about which version is correct. We’ve replaced our text with a quote from backpacker magazine.

  • Pauldclarke

     exactly… they also said strong coffee is needed since there are more oils in it…. how is anybody going to know if this is accurate in ANY way…. also… look at the clouds in the sky! Ill bet my life thats as or much more accurate…

  • David

    Now I’m beginning to think you don’t even understand what camping is.  If you don’t, just say so, and I’ll explain.

  • jasonw8photo

    I don’t drink coffee–can I just use a weather app or look at the sky?

  • Stephan Zielinski

    It’s like “Feed a cold, starve a fever”; out in the wild, one also hears “Feed a fever, starve a cold.”  One can find people quoting both versions because neither one is correct.

  • David

    Who makes coffee beforehand?  That’s ludicrous.  You have the pot you always carry, and the mug you always carry.  Boil the water in the pot, then pour it in the mug.  Coffee!  I’ve climbed mountains in six different countries, and guess what?  A phone would not have helped, as there is cel service in exactly ZERO of those wilderness areas.  Either you don’t understand camping, or you don’t understand cel phones.

  • Farmer Dan

     This is getting absurd. If you’re a troll, I fell for it.

  • Munson Erik

    The last thing I want is a cell phone when camping. The point of camping is to get away from the daily grind and enjoy life without the hustle and bustle. I bet everyone of you that are arguing this will try it, so shut the hell up.

  • Romanium

    you can’t play angry birds or check your email without a phone. there really isn’t any point in camping if you can’t use any apps, check stocks, or whatnot

  • Nate Whilk

    This is complete BS. Something like this only works if you have a container, something like a drum, with bottom and sides solid, and some kind of skin (like a balloon) stretched over the opening and secured in place, sealing air inside. THEN the skin will be concave or convex depending on barometric pressure (AND temperature) and the initial conditions when you sealed the container.

  • Donald Harrison

    Very suspect science / urban myth.

    Hot coffee oils strong enough to invert water’s surface tension meniscus from convex to concave based on atmospheric pressure change seems unlikely.

    Probably this is a modern adaptation of the old timey practice of fortune telling based on coffee or tea’s in cup bubbles, colloquially called the ‘money’.

  • lovingthatefke

    When the power shuts down/internet goes out, you’ll be the first one running in the streets screaming for help.

  • The_photographer_Tom

    All this talk about carrying a phone and ingredients to make coffee. Do what I do. I carry a piece of string and hang a medium sized rock on it from a branch. Then I read the instructions on this photo:

  • Edbasson

    I had to laugh, it seems the confusion is easily explained: your quote from Backpacker Magazine seems to be from a quiz, where the statement is either true or false. Personally I think it’s false, as high pressure should cause concave surfaces. But whether I’m right or wrong, I think you should be careful where you copy and paste your quotes from.

  • Edbasson

    I forgot to my copy and pasting, here’s the link I found:

  • Geoffrey Froment
  • 9inchnail

     I always drink my coffee with milk and there never are any bubbles to begin with. So I guess you can’t have milk. Then again, check your coffee weather forecast and add milk afterwards. Problem solved.

  • 9inchnail

     Because it’s explained in the article and WE know how to read.

  • 9inchnail

     You know you can shut off your phone but still keep it with you in case of an emergency, right?

  • me

    in the Amazon?

  • Me

    That confusion is caused by you saying it both ways! the text in the email sent out which has this article has it the wrong way and then the text here on this actual web page has it the right way. ;-) (assuming the way on the backpacker site is the right way)

  • Guillaume_parant

    It seems to be the opposite!

  • Afterglow82

    Yes, screaming for help in finding out if there might be a brief shower layer. The horror… The horror…

  • Afterglow82