Data for this web page comes from the Iowa State Environmental Mesonet (IEM) and spans the 30-year period from January 1, 1993 to December 31, 2023 for each station.

The displayed lines correspond to the minmum, 10th percentile, 25th percentile, mean, 75th percentile, 90th percentile, and maximum values that occurred on a particular date during this 30-year period. Only very basic data quality-control is performed, including a Gaussian smoother that was applied to the raw data to reduce noise and enhance figure readability. A sigma value of 3 was used for the 10th - 90th percentile lines; a sigma value of 1 was use for the minimum and maximum lines to reduce noise and filter out erroneous data. As such, these figures should be interpretted as rough benchmarks rather than true values. For example, a maximum high temperature on a given day may or may not be the station's true high temperature record, but should be in the ballpark.

For more precise, quality controled record information we recommend xmACIS.