The data used in this product come from the National Weather Service's (NWS) Cooperative Observer Program. Weather data are observed daily, then sent in monthly digests to a regional NWS office. The NWS then forwards the data to the National Climatic Data Center (NCDC) and appropriate state climate office, such as the Oklahoma Climatological Survey (OCS). Most observers record maximum and minimum ("high and low") temperature, precipitation and snowfall during the past 24 hours. Some observers record only precipitation. Nearly all observers record their observations around sunrise or sunset, and the weather data are credited to the day the observation was taken. The data referenced in these pages come almost entirely from NCDC's Cooperative Station Data Set, which is available for purchase online.

Notes

• February 29th of leap years is not considered in monthly averages and accumulations.
• All data have undergone a cursory quality assurance (QA) regimen. However, OCS continuously investigates its data archives to correct or remove erroneous data. If you suspect a data problem, please contact OCS.
• All temperature data are reported in whole degrees Fahrenheit. Precipitation is reported in hundredths of inches. Snowfall is reported in tenths of inches.

Key

• Period of record - The first and last years of observation at the station.

  Note: Some stations may not have recorded during some intervals within the period of record. The stations with large data gaps are noted, and only those years for which valid observations exist are considered for the monthly climate calendar.

• Long-term vs. Short-term stations - Long-term stations have at least 50 years of data. Short-term stations have periods of record less than 50 years, but more than 20 years. Stations with fewer than 20 years of data are not available.

• Active vs. Inactive stations - Active stations are those for which observations are available within the last three years. Inactive stations have not observed weather in at least three years.

• T Avgs - The period-of-record average high (red) and low (blue) temperature for the date.

  Note: This differs subtly from "normal" high/low temperatures, which use a specific 30-year subset of the data.

• Sig Prcp Freq - The percentage of dates during the period of record with at least one-tenth inch of precipitation.

• Extremes - The highest temperature, lowest temperature, most precipitation and most snowfall observed on that day at the station, with the year of observation. Monthly extremes (for example, the greatest daily rainfall observed in November) are highlighted in yellow.
  • High, Low T - Daily maximum and minimum temperatures are observed in whole degrees Fahrenheit.

  • Precipitation - The daily precipitation consists of rainfall and/or the liquid equivalent of any frozen precipitation (snow, sleet). Values are expressed in hundredths of inches. If precipitation was observed, but less than 0.01" was recorded, it is listed as a "trace".

  • Snowfall - The snowfall value represents the representative depth of frozen precipitation that fell on the day of observation. Values are expressed in tenths of inches. As with rainfall, observed values too small to be represented are listed as a "trace".

    Note: Hail has been treated inconsistently during the existence of the cooperative observer system. Sometimes it has been counted as snow, sometimes it hasn't. OCS has eliminated most of these hail-as-snow reports by requiring a minimum temperature of less than 40 degrees Fahrenheit. However, irregularities in temperature data have allowed a small number of hail-as-snow reports to survive. For example: a inch of snow reported during July is undoubtedly a hail event.

• Monthly Averages - all valid over the station's period of record
  • High Temp - the average of all high temperatures

  • Low Temp - the average of all low temperatures

  • Avg Temp - the average of all the average daily temperatures (which is the average of the day's high and low temperatures).

  • Precipitation - the average monthly accumulation of rainfall (plus the liquid equivalent of any frozen precpitation).

  • Snowfall - the average monthly accumulation of frozen precipitation.

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