Then refer to the chart to see how much your running times will suffer. For example, say your forecast is showing a high of 77 degrees Fahrenheit with 85 percent humidity. That’s a dew point of ...

The chart is a grid where you can find the heat index temperature by looking at the air temperature and relative humidity. For example, the NWS says if it's 96 outside and the humidity is 65%, the ...

She offers some recommendations in the brief, 2-minute video (posted above) on how to use humidity charts like this one to track the potential for your corn crop to develop tar spot.