Monsoon Season Impact on Indoor Mould Growth: SG Study

Abstract

This 24-month longitudinal study tracked mould growth patterns in 180 Singapore residential properties across multiple monsoon cycles. Northeast monsoon (Nov-Mar) showed 280% increase in new mould cases compared to inter-monsoon periods. Properties without dehumidification showed 4.2x higher mould incidence during peak monsoon months.

Seasonal Patterns

Season	Period	Avg. Humidity	Mould Index*
NE Monsoon	Nov - Mar	87%	280
Inter-monsoon	Apr - May	82%	120
SW Monsoon	Jun - Sep	79%	100
Inter-monsoon	Oct	83%	140

*Mould Index: Baseline of 100 during SW Monsoon

Key Findings

Peak Risk Period: December-January (highest rainfall + humidity)
Most Affected: Ground to 5th floor units (42% higher incidence)
Property Type: HDB corner units showed 65% higher mould rates
Dehumidification Impact: 76% reduction in mould growth with active humidity control

High-Risk Factors During Monsoon

Windows left open during rain (direct moisture ingress)
Wet laundry dried indoors without ventilation
Infrequent AC use allowing humidity buildup
Poor bathroom ventilation after showers

Monsoon Season Recommendations

Run dehumidifier 8-12 hours daily during NE monsoon
Keep windows closed during and after rain
Increase AC runtime or set to dehumidify mode
Check for water ingress around windows and doors
Dry laundry outdoors or use dryer during monsoon
Schedule professional inspection before November

Monsoon Season Impact on Indoor Mould Growth in Singapore Residential Properties

Abstract

Seasonal Patterns

Key Findings

High-Risk Factors During Monsoon

Monsoon Season Recommendations

Prepare for Monsoon Season

Abstract

Seasonal Patterns

Key Findings

High-Risk Factors During Monsoon

Monsoon Season Recommendations

Related Reading

Practical Guides

Professional Services

Prepare for Monsoon Season