Unfortunately, this state is one of the most polluted on the planet
Putting on a surgical mask isn’t going to assist you in this situation. Singapore has a reputation as one of the dirtiest nations on the planet. You can’t see the horizon at times because the air is so polluted.
During the winter, the weather might be particularly dangerous, so postpone your trip. Summer days aren’t a good idea either because of the high humidity levels. As a result, both winter and summer are cloudy and damp. So, your only options for returning are in the spring or the autumn.