Agreed, but remember the 19.2 C maximum temperature mentioned on the rover FAQ page is completely in keeping with the temperatures already known to be reached at this latitude from the Viking orbiter measurements.
That is, it is already known that near equatorial sites such as the Pathfinder site and Gusev reach 20 C during the hottest time of the Summer in daytime hours.
See also this report that modeled ground temperatures at the Pathfinder site, concluding 20 C was reached daily during the time of the Pathfinder mission:

THE MARTIAN SURFACE BOUNDARY LAYER.
G. R. Wilson1 and M. Joshi2, 1Jet Propulsion Laboratory,
4800 Oak Grove Drive, MS 183-501, Pasadena, CA 91109 (Gregory.R.Wilson@jpl.nasa.gov), 2NASA Ames Research Center, MS 245-3, Moffett Field, CA 94035 (joshi@humbabe.arc.nasa.gov).
Lunar and Planetary Science XXXI 1678.pdf
http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1678.pdf

Bob Clark

Modeled ground temperatures at the Pathfinder site, from "THE MARTIAN SURFACE BOUNDARY LAYER."