You will never escape the humidity of Singapore due to its position on the Equator. However, you can time your trip to avoid heavy soakings coupled with thunder storms and lightning. The “dry” season is between February and April. This doesn’t mean that it won’t rain. If you look at yearly rain charts, even in dry season you can expect 10 days with rain. 

February to June are the hottest months. You’re looking at an average of 31 degrees Celcius during the day and 24 degrees Celcius at night! That air conditioning machine isn’t being switched off overnight!