Permaculture is all about matching your growing activities with natural cycles. Therefore, information about weather trends in your area is the starting point for any garden plan.

Weather Underground has been a great resource for me for several years. In addition to weather forecasts for anywhere on the planet, the site has feeds from hundreds of private weather stations. Anyone can install a weather station in their backyard and share the data with weather enthusiasts all over the world via Weather Underground. The site has a cool feature that allows you to create a "weather sticker" to embed on a web site or blog, showing current conditions for any of the stations in the database. 

Setting up your own weather station can be great fun, and the data from it can help you plan your garden with site-specific information. You can spend anywhere from a few dollars to several thousand on a home weather station. Here are a few tips if you decide to purchase one. 

The lower priced models are surprisingly accurate. I have several digital thermometers and all seem to agree when placed side by side. I have also compared temperature readings using a research grade glass thermometer. All the digital ones are within a few tenths of a degree of the research instrument, which is plenty accurate for gardening needs.

I have an indoor/outdoor thermometer consisting of a base unit and wireless remote. Each day, the base unit displays the high and low temperatures for the previous day automatically. It also displays indoor and outdoor relative humidity. This device cost about $20 at our local DIY store.  Low-cost devices lack the ability to store long term information, however, leaving you to track trends with pencil and paper or a spreadsheet.

A few years ago I bought a fancier weather station for about $200. I ordered it online. Several competing brands sell home weather stations and the price can range up to several thousand dollars. Ours came from Oregon Scientific, and while we could, shall we say, suggest some improvements, overall it has been quite satisfactory. Some friends purchased a more sophisticated system from OS, and have generally been pleased, as well. Both stations measure indoor and outdoor temperature and humidity, wind speed and direction, rainfall rate and amount, and barometric pressure. The better unit permits installation of additional remote sensors. So, for example, you could have another temperature/humidity sensor in your greenhouse or swimming pool, along with the regular outdoor sensor, and both channels would be available on the base unit.

Besides merely taking readings, these stations have built-in software that calculates wind chill, heat index, and keeps track of maximum and minimum temperatures and rainfall amounts. Each has a USB port that permits capture of data to a computer. This feature vastly simplifies recording trends, and makes possible sharing your data via the Internet.

The external sensors in my station require batteries, while the more upscale station my friends bought features solar powered external sensors. In both cases the sensors transmit data wirelessly to the base station. I will go with the solar model should I purchase a new weather station. Changing batteries in the outdoor sensor for temperature, humidity, and wind data could not be simpler. You twist the plastic housing a quarter turn and it pops away to reveal the battery compartment. Done in 30 seconds or less. The rain gauge, on the other hand, has the batteries encased in a waterproof, gasketed housing that requires removal of eight tiny screws each time the batteries need changing. It is a genuine pain to change the batteries. I use lithium batteries in the rain gauge to minimize changes. They last about a year.

Both units came packaged with software that proved to be out of date and hardly intuitive to use. Fortunately, we were able to upgrade the software online, and often find answers to our questions from the manufacturer's web site. Oregon Scientific, however, provides little in the way of answers to most of our questions. In the future, I will look for online product reviews, especially with regard to software and support, before purchasing another weather station.

Another problem with all of stations that feature wireless sensors is the working range. When the package states a maximum distance between the sensor and the base station, it means under ideal conditions. Depending upon the construction of your home and the presence of obstructions like trees and outbuildings, the actual range of the device can be much less. More costly, professional quality weather stations typically feature much more powerful transmitters in their remote units.

In summary, if you don't mind keeping your weather readings in a notebook, you can find accurate weather instruments at low cost. If you want a more sophisticated weather station capable of being networked to your computer, spend some time on research before you spend your money. Either way, having good records of weather conditions in your garden can help you make design decisions as well as plan for food crops.