Have read on the forum many times that the temperature gauge indictor should be straight up in the 12 o'clock position. Anything other than that is abnormal. This can't be true in all circumstances though, during hot summer days, for example. Right?
At some point (<180 degrees?) the thermostat will be wide open with the fan running at full speed. At this point the only variable in the cooling system is the temperature and rate of flow of the cooling medium, i.e. the air passing through the radiator.
Yesterday the local temperature was 85+ degrees. My temperature gauge was at times hovering near the next gauge mark (the mark halfway between normal and the beginning of the "red" zone) depending on the engine load and the car speed. The higher temps were occurring in stop and go traffic but once I got going again the temp returned to "normal". Later in the day as things cooled off the temperature gauge had the reassuring straight up appearance.

Do others have a similar experience or is this something I should be concerned about?

TIA

Jim