Help - Utah Climate Center Data Types


Cooperative Observer Program. This data set has been used in countless climatological studies, legal litigation, insurance claims, and other various research applications. The data contains various parameters consisting of the previous day’s maximum and minimum temperatures, snowfall, and 24-hour precipitation totals that are initially obtained from state universities, state cooperatives, and the National Weather Service (NWS). Currently, there are approximately 8,000 active stations with cooperative observers, known as cooperative observing stations, but data are in these files for approximately 23,000 stations for various years. Selected Summary of the Day data from related file DSI-3210 for National Weather Service "first order" or principal climatological stations and "second order" stations have also been included in this file. The COOP database is updated monthly.

The record period and number of stations varies among the states. Most states began collecting data during 1948, but some began as early as 1946. Prior to 1948, most of these data were collected through cooperative agreements with state universities and other state organizations. Many years of records were digitized with some going as far back as the 1850s. It must be noted that NCDC has the observations from the time the station opened, but the NWS has the current data. Official surface weather observation standards can be found in the Federal Meteorological Handbook.


Global Summary of Day. This database contains summarized data which have been extracted from surface synoptic weather observations, exchanged on the Global Telecommunications Systems (GTS). The National Meteorological Center (NMC) of NOAA maintains an archive file of the complete surface synoptic reports which are received from the GTS. The Climate Analysis Center (CAC) extracts portions of these NMC archive files, performs an automated decode of extreme temperatures and accumulated precipitation according to WMO code manuals, and performs limited automated validation of the parameters. The data for all reporting stations are summarized on a daily basis to satisfy current operational requirements related to the assessment of crop and energy production. The GSOD database is updated monthly.


Automated Weather Observing System. The AWOS is a suite of approximately 600 U.S. stations, which measure, collect, and broadcast weather data to help meteorologists, pilots, and flight dispatchers prepare and monitor weather forecasts and plan flight routes. The AWOS data set records hourly data from this suite of stations and contains data for wind speed, direction, temperature, rain, and other climatological phenomenon. It should be noted that not all stations report information every hour and there may be time periods for some stations without data. NOTE: All times reported in the AWOS data set is ZULU (GMT). There are no offsets for local time zones.


The evapotranspiration computed is the so-called reference crop evapotranspiration or reference evapotranspiration, denoted as ET o. The reference surface is a hypothetical grass reference crop. The reference surface closely resembles an extensive surface of well-watered green grass of uniform height that is actively growing and completely shading the ground.

Temperature data are widely available at COOP stations; hence, several reference evapotranspiration equations are available in which temperature is the only required input variable. Of the temperature-based equations for computing ETo, the Hargreaves ET o equation is calculated here for the COOP dataset. The equation has the form:

ETo = 0.0023 (Tmean + 17.8) (Tmax - Tmin)0.5 Ra


ETo – is the reference evapotranspiration in millimeters per day. Tmean – is the monthly mean temperature (Tmax + Tmin) / 2 in degrees Celsius. Tmin – is the daily minimum temperature in degrees Celsius. Tmax - is the daily maximum temperature in degrees Celsius. Ra – is the extraterrestrial radiation in millimeters per day.

As a note of caution, the Hargreaves equation has a tendency to under-predict under high wind conditions (greater than 6 – 7 miles per hour) and to over-predict under conditions of high relative humidity.

Further explanatory details are in the Utah Climate book. An updated version will soon be available through the Utah Climate Center.

Current Weather Conditions

On the sidebar of the Utah Climate Center home page are current weather climate data and information. These data are automatically calculated and display current climate information including temperature, “feels like” temperature, wind speed and direction, barometric pressure, visibility, dewpoint temperature, relative humidity, and daily precipitation. Below current weather conditions, other useful information is also displayed such as the current phase of the moon and exposure time before frostbite and/or heat stroke warning levels.

Below current weather conditions, other useful information is also displayed, such as:

  • Record High and Low Temperatures
  • Record Precipitation
  • Normal (average) High and Low Temperatures
  • Normal (average) Precipitation
  • Current Phase of the Moon
  • Warning levels of exposure time before frostbite and/or heat stroke.

NOTE: “Precip. Today” is a measure of the amount of precipitation (rain, melted snow, sleet, etc.) that has been recorded since 12:00 a.m. local time.

Change Location of Current Weather Conditions

By clicking Change Location, two methods of changing the location are presented."Station Map" displays a google map interface which can be used to select a station within the desired location. "Enter Station ID" gives the option of entering a station\'s ID. The station ID must be known in order to use this method. It is recommended that first time users use the google map interface. Note that the station id can be found here by simply hovering the cursor over a station. Make note of this ID for future reference. If the station ID has known or has been obtained from the google map interface. The location can be changed by entering the station ID.