Export to raster tool changes the output values

Question

I am working with interpolated temperature data. The image's maximum and minimum values are 11.9 and -1.7, respectively.

I exported this image to raster using export to raster, but the max and min values of the output raster image are different from that of the interpolated temperature image.

I'm wondering why values of both images (temperature and raster) are not the same. They were supposed to be. Is there any way to make the values of the raster image be the same as the interpolated image?

Answer 1

It sounds like you have a difference in the number type.
Your output raster is most likely 8-bit unsigned, which allows integer values from 0 to 255. Changing that to a signed 8-bit allows integer values from -128 to 127.
The simplest way to allow decimal values would be set the raster type as Float. The downside to that is that each pixel takes up much more disk space, resulting in a much larger file.
Another option would be to multiply all your values by 10 to make them integers, and then use a signed 8-bit raster.