Automated Data Plotter

This application dynamically generates many types of graphs derived from various IEM data sources. Feel free to use these generated graphics in whatever way you wish.

Reset App IEM Explorer (Simplified)

1 Select a Chart Type

Choose from available chart types:

Growing Degree Day Obs + Near Term Forecast (#240)

2 Configure Chart Options

Select Station (STC000? are climate district, ST0000 state avg)

[IATAME] Ames Area [1893-01-01 till now]

Select start date to accumulate GDDs

(YYYY/mm/dd)

Image Pixel Size @100 DPI

Image Resolution (DPI) (50 to 500)

Select Output Format:

Plot Description:

This autoplot combines growing degree day observations along with a near term forecast from the deterministic GFS and NWS NDFD models.

The primary source of observations for this plot is from the NWS COOP network, but most of those observations are approximately 7 AM to 7 AM totals whereas the forecast data is approximately a calendar date. For sites that report morning data, the observations are backed up one day to better align with the forecast. This then creates a problem when running the app in the late afternoon/evening when the first forecast day is tomorrow and there is no observation for today yet. This is generally a thorny issue and why we can't have nice things.

This app uses Autoplot #9 to generate the GDD Climatology.

3 Generated Chart

CSV Data Excel Download

If you notice plotting issues with the image above, please contact us and provide the URL address currently shown by your web browser.

IEM Daily Features using this plot

The IEM Daily Features found on this website often utilize plots found on this application. Here is a listing of features referencing this plot type.

22 Apr 2025: Near term GDDs
26 Apr 2023: Daily GDD Forecast