Last I checked, licking one's finger and holding it up to the wind can be a fair indicator of what's blowing.
But if you're into activities like sailing, windsurfing, or flying your army of robot drones, you might want to check out Vaavud, a wireless wind meter that works with your smartphone.
The subject of a 20,000-pound ($30,456) Kickstarter campaign, Vaavud was developed by a Danish trio keen on windsurfing and kitesurfing.
You can plug the little wind meter into your phone's audio jack, or simply hold it near your handset. It works wirelessly and doesn't even have electronics.
The unit contains two magnets in the rotor that create a magnetic field when it spins. That effect can be measured by your phone's magnetometer, with the results displayed in meters per second, mph, knots, etc.
The developers say that so far, they've confirmed the gadget works with the sensor in the iPhone 4, 4S, and 5, as well as the Samsung Galaxy S2 and S3.
The idea is that you would take on-the-spot wind speed readings and then share them with friends and on online maps. Others can then decide if conditions are right to go sailing or fly an RC airplane.
I can already see CNN reporters whipping these out for effect in hurricane gusts.
With early-bird pledges all gone, Vaavud wind meters are now being offered to backers for $30 and up.