Search /tmp before /var/tmp and /usr/tmp -- this seems preferred.
SF patch #404564, Gregor Hoffleit.
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index fe4d291..7a1fc26 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -21,7 +21,7 @@
         pwd = os.getcwd()
     except (AttributeError, os.error):
         pwd = os.curdir
-    attempdirs = ['/var/tmp', '/usr/tmp', '/tmp', pwd]
+    attempdirs = ['/tmp', '/var/tmp', '/usr/tmp', pwd]
     if os.name == 'nt':
         attempdirs.insert(0, 'C:\\TEMP')
         attempdirs.insert(0, '\\TEMP')