To understand and fight SARS-CoV-2, different models are needed (i.e. one model cannot answer all the questions). A mathematical model can be an effective tool for understanding SARS-CoV-2 transmission and evaluating possible strategies. Here, we present two models based on the indirect transmission of SARS-CoV-2 that explain the impact of ambient temperature and air pollution on SARS-CoV-2 outdoor and indoor behavior. These models discuss temperaturebased lethality of SARS-CoV-2 and its spread. In addition, if SARS-CoV-2 is transmitted through particulate matter or surfaces, the temperature effect on its half-life is discussed. The dew point should also be considered instead of just the humidity factor, since a combination of temperature and humidity may play an important role in SARS-CoV-2 transmission.