Today I noticed the engine temp rising a bit. [Solved]

[titodj]

A couple of weeks ago I started getting the coolant level low warning, It would come up randomly and just for a couple of seconds.
I still need to figure out why, and I'm going to check the sensor connection as suggested.
(The coolant level is fine)

But I hadn't have any problem with the engine temperature before.
The needle was either all the way to the left when cold, and at 12 o'clock when at running temp, and never went higher even with the summer temps here in Las Vegas, but today I noticed that when I was stopped during a red light, the temperature went up, not all the way, but a little before the "red zone"

Then when I started driving went back down again, The fan in front of the radiator is fairly new, and I'm pretty sure that I've heard that is working a couple of times this week when I got home and turned off the engine.
I didn't heard it running today, so I guess that is a possibility, but assuming the fan is right, what else could be causing that change in temperature?

Thanks !!

It was both, the level sensor (that was old)
And the thermostat that was new and failed in less than 3 months
I replaced them, and all seems back to normal !