Here's a curious pronunciation scheme from MW online:
"Pronunciation: "tem-p(&-)r&-'men-t&l, "tem-p&r-'"
Now, this supports those of you who say "tem-pruh-MEN-t&l..
but what does the second scheme mean? Tem-per...MEN-t&l?
Neither of those offered seems to enunciate the "a" following "temper"...
...but I could be read those &s incorrectly. Help, please.
Edit Addition:
And here's from AHD online:
"tmpr-mntl, tmpr--"
Well, that didn't copy out correctly because AHD agreed with MW's first pronunciation, but the second one showed enunciation of the "a" in question.