CliGrow Crop Maturity App

CliGrow is a new agroclimate tool developed by the High Plains Regional Climate Center. It allows users to estimate crop maturity using growing degree days for any location in the lower 48 states. Estimates are available for ten different crops, with more arriving at a later date. The best part is that you can save the link to the graph and revisit your field’s up-to-date estimate at any time.

We have published a YouTube video about CliGrow here, or you can keep reading to learn more about using CliGrow.


Getting started with CliGrow is easy! First, navigate to the webpage. You will first find the location selection window. From here, you can pick anywhere in the lower 48 states. For this example, we have clicked on a location in rural North Carolina.

After clicking ‘Select Location’, you will see the main interface for CliGrow. Select the planting date for your field, then the crop type. For the moment, we are going to skip talking about the Crop Maturity Settings. Specify the freezing temperature you are most concerned with, then click “Start Analysis”. The plot may take a minute to load depending on your internet connection.

After the graph is done loading, you will see something like the screenshot above. In this case, we are showing the GDD accumulation for corn at a location in rural North Carolina. The graph is displaying a lot of useful information, so lets take a closer look.

The blue bars are showing the frequency of first or last freezes based on the temperature you selected. In this case, we can see that the latest a 28 degree freeze has ever occurred was in April of 2016. Similarly, in October of 2015 this location experienced its earliest ever freeze.

The green line is showing the accumulation of Growing Degree Days starting on the planting date, and the pink line is showing the average accumulation based on data from 1991-2020. In this example, we can see that this field is estimated to be growing at a near average rate so far this year.

In the example graph, you can see two colored vertical bars. If you did not select corn, you probably see only one bar. If you left the Crop Maturity Settings blank, you won’t see any. Each vertical bar represents the range of dates when maturity has occurred, based on the Growing Degree Value provided in the Crop Maturity Settings. In the example image, the green bar is showing that the silk layer has been reached earliest on June 20, 1991, and latest on July 7, 1997. If the green line showing the current year’s accumulation has reached the maturity Growing Degree Day value, a solid vertical bar will appear at that point, representing the estimated maturity point for the planting year.


The Crop Maturity Settings allow you to specify when you think your field will mature. Most crops in CliGrow calculate a single estimated maturity date, but corn has two. Corn is also the only crop which can estimate the GDD maturity point based on a provided Days to Maturity value, though those estimates are based on work done in the central United States.

We recommend using the “Comparison Year” feature to determine a good Growing Degree Day maturity value based on the last time a crop was grown in the field. This allows you to estimate any number of maturity milestones based on your operation’s needs.

Clicking the three horizontal lines in the upper right corner of the graph allows you to save the graph image, and the Table tab shows the data being graphed.

The “Bookmark this graph” button provides a link to this graph. You can save the link in any way you like, and next time you open it, you will see an updated version of the graph.


The High Plains Regional Climate Center is excited to hear how you are using CliGrow, and welcomes any feedback you have regarding the web application. Contact Us with any questions, feedback, or suggestions you may have.

Our development team is planning on adding several new features ahead of the next growing season:

Tool Spotlight – Spatial Climate Analysis

Click here to start using Spatial Climate Analysis

Spatial Climate Analysis is HPRCC’s latest way to explore data from the Applied Climate Information System (ACIS)! The web application offers several pathways for users to analyze data from ACIS stations and grid points, while providing an easy to use map interface.

Let’s take a closer look at the tool!

On the left side of the screen is a panel that lets you customize the map, and access different tools. The Product, Timescale, and Plot Style options change the ACIS data being displayed on the map. The Grid Point Inspector checkbox will enable the selection crosshair for analyzing grid points.

The Other Layers section contains other overlays which may be useful. The county overlay will only work when the map is zoomed in enough!

Any overlays that have been selected will have a legend entry added in the legend section.

The map panel displays all information selected in the left sidebar. You can click and drag to pan the map, or use the mouse scroll wheel to zoom in or out. The button at the upper right of the map will allow you to change the map in the background!

Hover over station points to view their values, or click them to open the station in the Station Data Explorer. There, you can create linkable graphs with the station data.

Enabling the Grid Point Inspector will change your cursor in the map to a crosshair. Click any location of interest to open the Grid Point Inspector!

In the Grid Point Inspector, you can create linkable graphs for any grid location in the contiguous U.S.!

As always, feel free to use the Contact Us page to ask questions or tell us how you are using HPRCC tools. You can also find us on Twitter @HPClimateCenter !

Explore Spatial Climate Analysis

Tool Spotlight – Water Deficit Trends

The High Plains Regional Climate Center is happy to announce that the new web application, Water Deficit Trends, is available for public preview! Users can analyze precipitation trends across the country. View current drought and precipitation data and trends, alongside current drought monitor information and USGS stream flows.

Access Water Deficit Trends here: https://hprcc.unl.edu/wdt/ Click the red question mark for help when you open the application.

Please Note: While we are excited to begin offering access to this new product, the full six month trend window will not be available until September 2022.

Using the Map Interface

The main interface of Water Deficit Trends

When you first open Water Deficit Trends, you will see a web map with colored shapes, and a side bar with different options. The data points plotted on the map are selected by the “Variables” panel, and the trend range allows you to select a week to compare today’s variable to. For example, by default, the panel has selected the 30 day Standardized Precipitation Index (SPI), and a “Trend Range” of 1 week. This will show the latest 30 day SPI values on the map, and the shape of the point will indicate whether the latest value is greater, less, or the same as the value 1 week ago. This can provide a quick glance at areas that may be experiencing drought improvement! Each data point can be hovered over to see the latest value, and clicking will open the Trend Analysis Panel for the station (more on that below).

The layers panel lists additional layers that may be overlaid. The latest US Drought Monitor may be plotted, rivers, River Forecast Center boundaries, and County Warning Areas are all included!

If you select the USGS Gages layer, a dropdown will be displayed which allows you to select a HUC region. All USGS gages with height and/or streamflow will be displayed, with the color estimating the flood stage. Please note that HPRCC provides the  flood stage for assistance in analyzing long-range precipitation trends and identifying areas of interest. Accurate information regarding floods can be obtained through the appropriate River Forecast Center.

Clicking a USGS Gage will display a pop-up bubble that shows the station ID and a graph from either the NWS Advanced Hydrologic Prediction Service, or the USGS National Water Information System (The graph can take a few seconds to load). Clicking the graph will open a larger version for USGS plots, or to the station page for AHPS plots.

The USGS Gages layer shows the current state and values of gages

Hovering over the layers icon in the upper-left of the map will reveal additional settings for the map. You can change the base map, or look at some layers provided through NASA’s Earth Observing System Data and Information System.

Additional layers can be found by hovering over the layers icon in the upper-left of the map

Trend Analysis Panel

Any data points for the layer you selected in the Variables panel are clickable, and will open the Trend Analysis Panel.

The Trend Analysis Panel opens with the Graph Tab

The graph tab shows a weekly graph with average temperature, precipitation, SPI, and SPEI. Each variable plotted is either a 30, 60, or 90 day value depending on the timescale selected in the dropdown at the bottom left of the graph. The Number of weeks dropdown sets the number of weeks displayed on the graph.

At the top of the graph, the date of each week is displayed, with the U.S. Drought Monitor status for that week displayed below the date.

The Table tab shows a data table of the values plotted on the graph. The table can be downloaded as a CSV or printed.

The Report tab shows a printable report with a brief narrative about the timescale and duration selected for the graph, information about the station selected, a weekly data table, a summarization of data from nearby USGS gages for the duration.

Start using Water Deficit Trends here: https://hprcc.unl.edu/wdt/

Tool Spotlight – Station Tool

The Station Tool allows users to find stations in a given area, view information about the station, and go directly to HPRCC tools to explore data for the station. Explore the Station Tool in this Tool Spotlight!

Few tools in HPRCC’s product inventory have the breadth that the Station Tool does. When you are unsure of which weather station is appropriate for your use case, or are unfamiliar with an area, Station Tool steps in to help you locate a station and direct you to other tools in our inventory.

The Station Search form within Station Tool

On the surface, the Station Search form looks self-explanatory, but there are actually some advanced capabilities hidden in the search box! Here are the different search methods you can try!

  • City Name
  • County Name
  • State Name/Abbreviation
  • Station ID

Larger areas will take more time, since the Station Tool is requesting information from ACIS about all of the stations in an area!

After performing a search, you will have a list of stations in the left pane, and a map of station locations on the right. You can select a station in either pane to reveal information about a station.

The results after searching for a station in Station Tool

Inside of the station dialog is information about the selected station, along with links to the Station Data Explorer and Station Report Tool. The unique Annual Overview Graphs are also available from this dialog.

Annual Overview Graph for Charlotte Douglas Airport