Arbitrary operating conditions, such as the temperature dependence in the fiber link impose a challenge for the extension of radio-over-multimode fiber techniques. Temperature impairment characterization is analyzed over the broadband transmission bands that can be present in the frequency response of multimode fiber (MMF) supporting multiple-GHz carriers delivering schemes. Experimental results show that these transmission bands are dramatically influenced by the hysteresis of heating and cooling temperature cycles, respectively. The influence of the MMF graded index exponent tolerance on frequency response at higher bands is also analyzed. And this variation can be directly attributed to environmental temperature changes that could affect the MMF link. Additionally, selective mode-launching schemes combined with the use of narrow line-width optical sources are experimentally demonstrated to enable broadband transmission, not only at short but also at middle-reach distances over MMFs.