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 Weather » Interpretations |
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| History | Temperature | Rainfall | Evaporation | Air Movement | Relative Humidity | Soil Temperature |
| History | ||
The Texas Agricultural Experiment Station at Stephenville was established in 1938 and temperature and rainfall data have been collected at the station since mid 1941. Daily readings of rainfall and temperature for this area from 1918 until mid 1941 have been obtained from the Southern Region Climatic Center in Baton Rouge, LA, although there are many gaps in the readings. Monthly rainfall readings collected in the Stephenville area since 1895 are also available on this website. Additional instrumentation have been added and in addition daily readings are now taken for soil temperature, air movement and direction, evaporation, relative humidity and solar radiation. The Center has been designated by the National Weather Service as an Official Cooperative Observer and readings are sent to the NWS daily. |
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Temperature |
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Air temperature should be measured six feet off the ground and the thermometer protected from direct sunlight and precipitation. Provision should be made for continuous air circulation to the temperature sensors. Temperature readings for station data are taken from high and low recording thermometers housed in a Cotton Region type shelter. An electronic thermometer is used for NWS data and a strip chart recorder on a hygrothermograph provides a continuous temperature record. |
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Rainfall |
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Rain gauges should be mounted in the open with no obstructions within five feet of the collector. Rainfall is measured at the Center in a Universal Rain Gauge. The gauge has an expanded collector with a 1:10 ratio allowing measurement to the nearest .01 inch and it has a twenty inch capacity. A weighing gauge provides a backup. Additionally for NWS records rainfall is collected in a Fisher-Porter rain gauge which records readings in fifteen minute intervals on a paper tape. |
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Evaporation |
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Evaporation is measured from a Type 1 evaporation pan. The pan is four feet in diameter and one foot deep and is mounted on a wooden pallet four inches off the ground. Readings are taken with a hook gauge mounted in a still well in the pan. |
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Air Movement |
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Air movement (wind) is recorded at the Center by an anemometer mounted by the evaporation pan eighteen inches off the ground. By measuring in this manner the readings can be used for evapotranspiration data useful for irrigation studies. Air movement is posted as a cumulative 24 hour reading. The direction of air movement is noted when daily readings are taken. Air movement is extremely variable and if data is needed for purposes such as spraying it should be measured at the site and time of treatment. |
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Relative Humidity |
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Continuous readings of daily relative humidity are recorded on the strip chart of a hygrothermograph. The daily low and high humidity readings are posted on the website. |
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Soil Temperature |
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A soil probe is buried four inches deep in the center of a four by six foot bare soil plot. From ground level to four inches is the region of most plant roots. The high and low soil soil temperatures are posted daily. Back to Weather Page Back to Center Home |
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