Is my '93 90CSQ running a little warm?

[Diana Johnson]

This has been bugging me since the first day I took this car home three
weeks ago.  The temperature gauge needle used to sit at about 1/4 of the
scale and even on a hot day would sit a little below half way.  The
gauge needle on this car is usually exactly 1/2 way up the scale unless
I'm driving on the freeway, and it's only 40 outside.  It started to
overheat about a week ago, so we took apart the coolant reservoir and
found a crack.  After replacing it with a new one and tightening the
hoses, I really thought it would run cooler.  Am I being paranoid or
should I be nervous about summer?

Diana