Angell Global Ground Level Balloon Data 1958-2004 from:
http://cdiac.esd.ornl.gov/trends/tem...ll/angell.html
Just like the ground level observer data, the
warming rate is faster in winter than the summer.
Annual .16 +- .02 K/decade
Winter .18 +- .03 K/decade
Spring .17 +- .03 K/decade
Summer .14 +- .02 K/decade
Fall .16 +- .03 K/decade