I want a home weather station? What should I buy?

One of the most frequent questions I get is from people wanting to set up a weather station in their home. What should they buy? Where should they install it?

Lets try to tackle these important questions.

Having your own weather observations is really marvelous. There are very large variations in weather locally and you CAN'T assume that your home or apartment has the same conditions as Sea-Tac airport or one of the limited collection of stations presented on TV or in the paper. A few years ago I ran around the city with a bunch of 101 students in specially instrumented cars--temperatures varied by 15-20F on a cold winter night! (the graphic is in my book if you are interested). Having your own observations can help calibrate your gardening...when to put in or protect that delicate plant. Taking weather observations really brings you closer to nature, makes you more sensitive to natural rhythms and variations, makes you a better observer, and has a calming, salubrious effect on your disposition. Yes, weather observers are a happier lot.

One of the great revolutions of the last decade has been the availability of a wide range of weather instrumentation at a reasonable cost, some with near-professional calibration. And the second revolution has been the distribution of many of these observations over the internet. Tens of thousands of individuals around the U.S. put their observations online in real-time, and these are viewable on sites such as weatherunderground.com.

So what should you buy? Well, if you want to invest in very good equipment, we have found that the Davis Vantage Pro hardware is really excellent (see image above). This system can cost you $ 500, but you can often do better with a little internet shopping. If you have extra cash I was get the aspirated thermometer (solar powered fan for the enclosure). You can also get software for connecting the unit to your computer.

Now what if you don't have so much $? No problem. You can buy inexpensive gear with less accuracy that still can tell you a great deal. For example, COSTCO sells Oregon Scientific and LaCrosse weather stations for $ 100-200, with similar prices from others over the web. But you get what you pay for. And many of them have unshielded thermometers, so BE SURE to put then in a shady location on the north side of your residence, out of the rain.

Out of work or just on an allowance? No problem again. You can buy a digital thermometer or an alcohol one for $10, a rain gauge for $5-10, a cloud chart for $5, and a barometer for $25.00. And a pad to record your observations. That is how I started. As did Thomas Jefferson.

For the computer oriented, getting your weather station interfaced with a computer is great fun, and the interfacing software often comes with neat archival and plotting software. But the fun doesn't stop there. You can automatically send your data to groups such as weatherunderground.com so you and others can view it online. In fact, even if you don't have a weather station, you can often get a close-in weather view for your location by going to that site. The map below shows the weatherunderground observations right now (10 AM Saturday) over a small portion of Seattle.

There are other collections of volunteer weather observations, which are generally less user friendly. One is the Citizen's Weather Observer Program (CWOP) http://www.wxqa.com/.

But let me make one thing very clear. The quality of these volunteer and hobbyist observations vary widely in quality. Some are very good. Some are very bad. Why bad? Generally poor exposure and placement.

Temperature should be measured in the shade or in a protected (white) enclosure at 2-meters above the surface. Rain gauges should be in the open, not near splashing roofs or protective trees. Winds should be taken on masts that are not near buildings or trees (and not a the peak of roofs where wind is accelerated). You get the message.
One of the great challenges for professionals like me is how to use this varied, heterogeneous dataset.

So have fun taking your own observations!