How hard would it be to add an anemometer to a cycling computer?
 

That's a wind gauge. :) I'm thinking you could have sensors on all four corners of the computer and an algorithm that applied the actual bike speed and determined the actual direction and strength of the wind as well as the effective direction and strength in combination with the motion of the bike.

Ibike uses this I believe for their virtual power meter.

Direction would be the most important wind measurement to me - so I can constantly modify my route and keep it at my back.

That's a neat trick. How do you get home? :)

Seriously, I eat the wind on the way out and have it behind me coming home. I am just finding that weather.com is seriously underreporting the wind speed here in Houston lately (at least I hope that is the problem!). I would like an accurate measurement in situ.

It's easy to mount an anemometer on a bike. It's hard to mount an anemometer that will tell you air speed and yaw angle with reasonable precision, though that obviously depends on what you mean by "reasonable precision."

Correct. Neat idea, though.

I'm wondering if tiny strain gauges or pressure sensors could do the trick. I would think +\- 0.2 mph would be plenty good enough precision.

Variances in mounting location, body position, etc. would render it useless. Cool idea, though.

I use the "stop and put a wet finger in the air" method of determining wind direction. Flawless and free.

If by anemometer you mean a meter to measure how anemic you are riding that day, then I think a power meter can do the trick :D. While the speed changes depending on wind, elevation etc. the power meter measures your direct performance. However, if what you want is an indicator of wind direction then you could possibly invent something!

I say the problem is that the wind generated by speed will obviously indicate that it's always a headwind and putting a barrier would then overrule everything coming from the front completely. You could have some sort of speed sensor matched with a GPS device. The Speed sense will calculate the wind produced at certain speed with no other factors included. The GPS will help to indicate where you are headed or your bicycle is pointing and as a base it will substract the windspeed produced by speed to the total that intakes directly from the front. In the back you can do the same thing but the inverse, with the speedsense doing the same. From the sides just regular sensors since you are not moving on those dimensions.

I know it's probably a stupid idea but it made me think!.. which is something that I don't do often.

Problem is having to stop every time you take a turn.

Me too, it's been like living in a wind tunnel this Spring in the Hill Country.
"Official" wind speed is far less than what's whipping up out here so I'm going to mount a digital weather station on my rooftop to get the real wind speed. It matters to me since I like to ride my FG, but not in "surprise red flag" conditions when a road bike would be grudgingly deployed instead.

-Bandera

Well, there are lots of alternatives. +/- 0.2 mph is about 0.1 m/s which is often good enough. The Aerostick uses differential pressure sensors so it can tell airspeed and yaw angle within a degree or so, but there are other ways to do it. One of the problems is getting the sensors out far enough away from the bike/cyclist so that you don't get "bow wave" effects. You can do that by by going out in front, or up above, or out to the side of the bike/cyclist, but for the Aerostick we went out front to minimize drag contribution from the sensor itself. But if you don't need this kind of precision you can go much simpler.

Official wind speed is measured at 10 meters above ground. Wind speed at about 1 meter (which is what affects cyclists) is less, sometimes quite a bit less depending on local terrain and vegetation.

I'd go for a rain gauge as well.

It shouldn't be too hard to monitor perceived wind speed and direction out in front of the bike with software to calculate the actual wind speed and direction based on that. Why you'd want to bother is the question.

I can think of reasons.

I would think sensors on all sides with the appropriate software to do the additions and subtractions that would yield the correct real and apparent wind speeds and directions.

A couple of these should get you started. You'll want to connect them to appropriate pitot tubes and log the data somehow.

Once it starts, it won't be long before the manufacturers offer full meteorological stations for bicycles.

They have them for smartphones already...the trick would be to have the phone mounted properly.

VAAVUD Wind Meter for Smart Phones | West Marine

Or you use a weather app on your phone.

Right now I can see a dozen reporting stations within ten miles of my house.

You might make it work with only two, but you also need to know the ambient air pressure. Many air speed sensors are designed as a kind of fluidic comparator for this reason, with one pressure plate in a still area.

I've kicked this around with a buddy in the context of avionics and yes it's possible up to a point but it gets tricky real fast for any kind of precision. I understand one of the attractions: with speed, weight and grade you could get a power estimation (since there are experimental methods to calibrate for drag-area). There is a relatively cheap product which purports to do this. But the devil is in the details, and it's not so easy to get enough precision that the results aren't thrown off too much to be useful.

To calculate power, given speed, weight, cda, slope, ala I bike.

Or you could just get a real power meter.

Would you really need more than one front facing sensor? If the computer knows ground speed it should be able to use a simple algorithm to calculate wind speed. Direction would be harder but a 30mph measured wind speed and 20mph bike speed would mean an effective 10mph headwind which might be all that really matters. Of course, maybe an ANT+ helmet mounted sensor would provide more info. Seems it would need to be out of the way of your body though for any accurate recording.

I'm impressed, not one enemameter joke yet.