IR images are converted from the original satellite data to black and white images, just as in the visible channel. In the black and white image, clouds are usually lighter shades of gray or white and represent colder temperatures, while land and water features are dark gray or black and represent warmer temperatures. Notice the Celsius temperature scales to the left of each image.

At the top edge of the image, the date and time the satellite collected the data is displayed. Coordinated Universal Time (UTC), not local time, is shown. Learn about UTC-local time conversion on the next page.

IR images are often colorized to bring out details in cloud patterns. Individual forecasters may apply different color palettes to the imagery. In the colorized imagery shown here, clouds that have cloud-top temperatures colder than -20ºC (-4ºF) are shown in yellows, blues, and reds. Clouds that are warmer than -20ºC (-4ºF), land, and water features are shown in gray or black and represent warmer temperatures.

Why is this information important? Infrared imagery provides us with temperature information that forecasters use to estimate cloud-top heights. This is important because taller clouds correlate to more active weather, such as stronger thunderstorms or heavier snow.