Singapore is an year round destination. Winter brings a bit more rain as it is the Monsoon season, though you won’t notice a significant difference in the weather no matter what time of year you arrive. The crowds tend to be at their peak during the holidays due to the combination of winter travelers and holiday festivals. November through early January, June and July are when accommodation rates are at their highest. The crowds peak again in June and July during the Great Singapore Sale, with hotels filling to capacity. During this time, you may also experience throat and eye irritation from the smoke and haze produced from the clearing fires.
There is a slight break in the tourist traffic during late summer and early fall, with the exception of mid-September due to the Singapore Grand Prix. Although the Southwest Monsoon arrives around this time, it’s less severe than its Northeast counterpart.