At low speeds, oil temps tend to stay on the cool side - unless the engine gets caked with mud. It's high-speed running, especially in suburban traffic, where you cycle between mid 50s for a mile or two then sitting in traffic. The reason being that the motor isn't making much power at low speeds. Engines are maybe 30% efficient. The rest of the gasoline burned is wasted as heat. MPH takes hp, more power = more heat generated. If you want to eliminate the guesswork, source an oil dipstick thermometer.
FWIW, in 85F ambient air temp, I'll see oil temps around 90-95C cruising along steadily at 55mph. At those same speeds, stopping for traffic every few miles will push oil temp to 100-105C. Take the bike offroad, with speeds below 30mph, and oil temps won't go above 80C.