There is NO SUCH THING as "degrees Kelvin", there are degrees Centigrade, degrees Fahrenheit and Kelvins, for which the abbreviation is K. I used K as I had no easy way of putting a degrees symbol in the email: there is a symbol ° but it will probably look different depending on what font people are using.
(and for people who haven't met them, a temperature in Kelvin is the temperature in degrees Centigrade + 273.15. In fact it is defined such that 0 K is "absolute zero" and 273.16 K is at the triple point of water, 0.01 degrees C).
So yes, what I mean is the equivalent of a 1.5 degrees Centigrade variation in temperature.
Roger Moss