The answer is that the solar radiation heats the thin atmosphere of Mars but hot air rises up and it also lift its small dust (since Mars has low surface gravity of 3.711 m / s 2 they are almost weightless) and dust-storms begin to form, swirling at great speeds due to the thin atmosphere probably due to formation of different pressure in the atmosphere (what we call in earth as hurricane) The greater the temperature, the better chance of dust storm.
Caption this Meme
