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  Home >> CEES Weather Station - Weather Parameters


Below is a listing of all weather parameters derived from our TAMIU
Weather Station along with a brief explaination. Here is a link to
a tab-deliminated text file (spreadsheet compatible), that contains
a summary of past weather observations.
All parameter represent
instantaneous measurements updated every 5 minutes.

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Air Temperature: A measure of the average kinetic energy of air molecules at 2 meters (~6 feet) above the surface.
Soil Temperature: A measure of the average kinetic energy of air molecules immediately below the surface. Typically varies much less than air temperature.
Relative Humidity: A measure of the amount of water vapor in air compared with the amount of water vapor at saturation (100%). Range between 0 to 100%.
Barometric Pressure: A measure of the force exerted on the surface by the overlying air adjusted to sea level elevation. Typical range 950 to 1050 mBar (approximately 1000 mBar equals standard atmospheric pressure). Higher pressures normally indicate fair weather and lower pressures stormy weather.
Wind Speed: Average velocity of the atmosphere over a 5 minute period measured in miles per hour.
Wind Direction: The direction in which the wind is coming from measured in the degrees of a compass (N = 0 degrees, E = 90 degrees, S = 180 degrees, and W = 270 degrees).
Rainfall: Liquid equivalent precipitation that has been recorded over the last 15 minutes.
Solar Flux Density: The quantity of solar radiation that strikes a square meter measured at the end of the five minute collection interval.
Total Solar Flux: The quantity of solar radiation accumulated during the entire data collection interval.
Dew Point Temperature: The theoretical temperature at which water vapor will begin to condense from the atmosphere. When air temperature = dew point temperature the relative humidity = 100%. For more information please consult : (http://meted.ucar.edu/awips/validate/dewpnt.htm).
Wet Bulb Temperature: The lowest temperature that can be obtained by evaporating water into air at a given constant pressure. Wet bulb temperature lies somewhere between dry bulb temperature (air temperature) and dew point temperature. For more information please consult: (http://meted.ucar.edu/awips/validate/dewpnt.htm).
Heat Index: Is the apparent temperature and is a measure of how hot the atmosphere feels when relative humidity is added to the actual air temperature. Valid only when air temperature is greater than 80 degrees F and relative humidity is greater than 40%.
Wind Run: Is the total distance that the wind has traveled during a particular time in a particular direction.
Wind Gust: Maximum instantaneous velocity of the atmosphere measure over a 5 minute period.
Rainfall (since midnight): Liquid equivalent precipitation that has been recorded since the previous midnight.
Rainfall Intensity (15m): Liquid equivalent precipitation rate in inches per hour determined based on the last 15 minutes of precipitation.
Hourly Evapotranspiration: Hourly crop referenced evapotranspiration calculated by the Penman-Montheith equation using the measurements of wind speed, air and soil temperature, relative humidity, and solar radiation.
Daily Evapotranspiration: Is a progressive summation of hourly evapotranspiration values.

Daily evapotranspiration is a value that can be used to determine plant irrigation water needs.