Temp Change

I live in Seattle and the temp just got cold enough to frost. I have a new radiator and new coolant hoses. In the last two days the temp gauge has risen up a little beyond normal operating temp. I have driven in 98 degree weather and it never changed. My question is why the change when the weather is actually colder than it ever has been before. Could it be the thermostat is going out?
Thanks!

What is up, does anyone know at all? Need some help…

it is an odd problem. the thermostat would be the most likely culprit. the thermostat may be malfunctioning due to the colder weather. it is electronic. do you have enough coolant and is it the right kind?
have you heard the fans running when the gauge rises past a certain point?
if the coolant is fine and the fans aren’t operating when they should, they are controlled by the thermostat. then that would leave the thermostat to being your culprit.

fyi: you have alot of great members in the seattle area. search the members lists. get to know them and go to the meets. it will be invaluable if you plan to work on the car or do any mods. good luck.