A wireless communications device may include a portable housing and a temperature-compensated clock circuit carried by the portable housing. The device may further include a wireless receiver carried by the portable housing for receiving timing signals, when available, from a wireless network, and a satellite positioning clock circuit carried by the portable housing. A clock correction circuit may be carried by the portable housing for correcting the temperature-compensated clock circuit based upon timing signals from the wireless network when available, and storing historical correction values for corresponding temperatures. The clock correction circuit may also correct the temperature-compensated clock circuit based upon the stored historical correction values when timing signals are unavailable from the wireless network, and correct the satellite positioning clock based upon the temperature-compensated clock circuit.