   Home Weather Monitoring - January 1, 2003 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County North central Arizona residents know that weather is highly variable from place to place, even across very short distances. Weather prediction technology continues to improve, but we simply have too many variables to correctly predict the weather all the time. Besides, life might get boring if we knew what the world was going to be like every day. Weather is important to plant growth and measuring it will make us better gardeners. A rain gauge (precipitation gauge) and max/min thermometer are the two most useful instruments for gardeners. They are simple, and relatively inexpensive. Simple rain gauges come in two basic designs. The "round" type consists of a clear plastic cylinder with graduated marks to indicate the volume (depth) of rainfall in inches or centimeters. The "tapered" type are wedge-shaped and have the graduated marks on a flat surface. In both designs, the collection area is larger than the storage area. This serves two purposes (1) to increase the sampling area such that a representative sample is collected, and (2) to make the graduated marks farther apart so that an accurate reading can be observed. Proper installation of your rain gauge is critical. The bracket of the gauge should be fastened to an upright post that allows the gauge to sit above the ground. The top of the gauge should be 5 inches above the top of the post. The gauge should sit firmly in the bracket. Placement should be away from any buildings, trees, walls or other tall objects that could distort the readings. On remote sites such as rangeland pastures, a simple rain gauge can be constructed of a 30-inch length of 2 inch PVC pipe. A PVC cap is glued onto one end. The pipe is then hose clamped open-end-up to a fence post. Small volumes (1-2 inches) of antifreeze and automatic transmission fluid (ATF) are put into the pipe and a baseline measurement is taken with a measuring tape. Any precipitation entering the pipe will mix with the antifreeze and remain a liquid even during freezes. When visiting the site, depth readings are taken, giving the amount of precipitation since the last reading. ATF is oil that floats on top of the water and antifreeze preventing evaporation. Its red color also makes it easier to read the depth. It should be cleaned and replenished at least once per year. It is also a good idea to put a piece of hardware cloth inside the opening to prevent birds, rodents, and other small animals from entering the pipe. Max/min thermometers also come in different designs. The regular type is either mercury or alcohol filled and tracks the maximum and minimum temperature since the last time the instrument was reset. Daily resetting will give the previous day's max and min temperatures. Place your outdoor max/min thermometer out of direct sunlight and near the area that you are concerned with monitoring (i.e. your orchard or garden). Recently, electronic max/min thermometers have become widely available for very reasonable prices ($40). These instruments will usually provide max/min temperatures for indoor and outdoor locations. Some come with alarm systems to warn when temperatures dip below or above a given set point. Others are available with wireless sensors that transmit the data back to the main module. Some of these can be set up for multiple wireless sensors and personal computers. Avid gardeners should seriously consider putting in a rain gauge and max/min thermometer. If nothing else, weather makes for great conversation. Finally, keep a journal to record the your weather observations. Happy gardening in the new year! The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/. |