IEM :: COOP Quality Controlled and Estimated Data Download

If you are looking for actual NWS COOP observations with no estimating and very little quality control done, check out this page. If you are looking to download the entire dataset, please check out this directory!

This page allows you to download observed, sometimes quality controlled, and sometimes estimated once daily reports from the NWS COOP network. More detailed documentation exists here and should be consulted before using the data.

The quality controlled data for Iowa is currently updated to 01 Jan 2018. While data is available for dates up until yesterday, the values are estimated by the IEM. The quality controlled data is provided to us by the Iowa State Climatologist. News items are posted to the homepage when a month's worth of data is sent to us.

Data is also available from the following states: Illinois , Indiana , Iowa , Kansas, Kentucky , Michigan , Minnesota , Missouri , Nebraska , Ohio , North Dakota , South Dakota , Wisconsin. This information is mostly estimated until NCDC provides updated GHCN datafiles, which the IEM then merges into this dataset. The unfortunate side effect is that data changes as new information becomes available.

If you really need calendar day data and other variables like wind speed and relative humidity, check out the IEM Reanalysis effort.

The purpose is to provide a dataset that does not have holes in it for temperature and precipitation and is updated up until yesterday. Unfortunately, these values are not on a local calendar day, so please be very careful before use. Unfortunately, long term observations that are on local calendar days does not exist for many locations!

1. Select station(s):

2. Select Start/End Time:

Please note the start year in the station selector. Some sites start in 1951 others are earlier. If you only want data for one day, set the start and end times to the same value.

	Year	Month	Day
Start:
End:

3. Select Variables / Model Input Format:

Select either one or more data variables

4. Specialized Data/Model Formats

When you select a given data format, it will override any selected variables above and formats below. These are specialized formats typically used for modelling and their choice dictates the variables to be included. Please contact us to have your format added to the list!

5. How to view?

6. Data Delimitation:

This option is only relevant if you did not select "Excel File" from #4 above.

7. Include Latitude and Longitude in output?

8. Supplement 2018's data with scenario year

Optional! For some purposes, you may wish to have a complete (Jan 1 - Dec 31) set of data for the current year. Of course, this period is in the future and observations do not exist! This option allows you to fill out the current year with data from a previous year. If data for Feb 29 is needed and not available from past year, Feb 28 data is simply repeated.
Yes, use this year for replacement:

9. Submit Form:

Please be patient and only submit this form once. It may take 10-20 seconds to get a response.