2025 West Pacific typhoon season: Preparedness Guide

The West Pacific typhoon season presents significant risks to communities, infrastructure, and businesses. Proactive planning and preparedness are crucial to ensuring safety, minimizing disruptions, and facilitating recovery efforts. This guide provides an overview of the 2025 typhoon season, potential threats, and best practices for preparedness, response, and recovery.

Typhoons are intense tropical cyclones that form over the Northwest Pacific Ocean, characterized by sustained wind speeds of at least 119 km/h (74 mph). These storms can generate extreme winds, heavy rainfall, storm surges, and landslides, posing substantial risks to affected regions.

The West Pacific typhoon season refers to the period when tropical cyclones most frequently form in the Western Pacific, affecting numerous countries and territories across Asia and the Pacific. Unlike the Atlantic hurricane season, which has a defined timeframe, typhoons in the West Pacific can occur year-round. However, activity generally peaks between May and November, with the most intense storms forming between July and October.

Geographic scope

The Western Pacific basin is the most active tropical cyclone region in the world. Typhoons that develop here primarily impact:

• East Asia: China, Taiwan, Japan, South Korea
• Southeast Asia: The Philippines, Vietnam, Thailand, Malaysia
• Pacific Islands: Guam, Palau, Northern Mariana Islands, Federated States of Micronesia

The region falls under the monitoring of the Japan Meteorological Agency (JMA), which serves as the official Regional Specialized Meteorological Centre (RSMC) for the basin, issuing warnings and forecasts. Other national agencies, such as PAGASA (Philippines) and CMA (China), provide country-specific updates.

Typhoon formation and classification

Typhoons form when warm sea surface temperatures (above 26°C) and favorable atmospheric conditions create strong low-pressure systems. The JMA’s tropical cyclone intensity scale categories tropical cyclones based on their 10-minute sustained wind speeds. The classifications are as follows:

Of note, other national agencies use their own country specific classifications. This scale differs from others, such as the Saffir-Simpson Hurricane Wind Scale, which is based on 1-minute sustained wind speeds. The JMA’s classification helps in issuing warnings and advisories in the West Pacific region.

Risk environment overview

Typhoons continue to be a major source of disruption in the West-Pacific region, impacting communities, infrastructure, and businesses. However, there has been a shift in the characteristics and intensity of these storms in recent years, resulting in an increased level of risk for organizations.

Although the overall number of typhoons has remained relatively stable, there is growing evidence that the storms which do form are becoming more destructive. A rising proportion is now reaching Category 4 or 5 intensity, driven by warmer sea surface temperatures. At the same time, storms are intensifying more rapidly, often strengthening dramatically in the 24-48 hours before landfall – leaving less time to respond. Typhoons are also producing heavier and more prolonged rainfall, increasing the risk of flooding and landslides, while slower storm movement can extend damage over a wider area. There are also indications that storm tracks are shifting, with higher-impact events occurring further north than in previous decades.

These changes present growing challenges for businesses and organizations with operations in the region. Infrastructure may not be designed for the scale of modern storm events, while assumptions based on historical risk profiles may no longer hold true. The increased intensity, unpredictability, and reach of typhoons mean that even well-prepared companies can face severe disruption without updated planning.

Proactive, location-specific planning is now essential to minimize losses, ensure personnel safety, and maintain operational continuity. Businesses should assess both direct impacts (e.g., wind, flooding, landslides) and cascading effects such as supply chain disruption, prolonged power outages, and displacement of workers.

Key risks and impacts

Typhoons typically involve a combination of strong winds, intense rainfall, and storm surges. The impacts are now magnified due to the above climate-linked factors:

• Coastal inundation and infrastructure damage: Sea-level rise and stronger storm surges increase flood depths and erosion risk, threatening roads, ports, bridges, and power infrastructure.
• Landslides in mountainous areas: More extreme rainfall events are saturating soil faster, increasing the likelihood and severity of landslides that can destroy homes and block vital access routes.
• Disruption to transportation and power grids: Heavier winds and flooding damage road, rail, and air transport systems, while power lines and substations remain vulnerable to extended outages.
• Casualties and mass displacement: With stronger and less predictable storms, the risk of large-scale evacuations and overwhelmed emergency systems continues to grow.
• Supply chain disruption: Port closures, road washouts, and factory shutdowns can cause cascading effects across regional and global supply chains.

Vulnerable sectors and populations

Certain groups and sectors are particularly vulnerable to typhoon impacts:

• Coastal communities: These populations face the greatest risk from storm surges, flooding, and high winds.
• Mountainous or elevated regions: These areas are prone to landslides where intense rainfall saturates unstable slopes. Communities, infrastructure, and transport corridors in these zones face heightened risk from soil collapse, road blockages, and structural damage.
• Urban centers: Poor drainage systems and high population density can exacerbate flooding and logistical challenges.
• Agricultural sector: Crops and livestock are at risk from flooding and strong winds, impacting food supply chains and local economies.
• Industrial and manufacturing sectors: Production and logistics may be severely impacted by structural damage, power outages, and supply chain disruptions.
• Health and emergency services: Hospitals and emergency responders may face surges in demand while dealing with infrastructure damage and power outages.

Emerging patterns and climate considerations

Recent typhoon seasons illustrate how climate change is reshaping regional risk profiles.

• The Western Pacific continues to average 20-30 typhoons annually, but a higher proportion now reach severe intensity.
• The number of rapidly intensifying typhoons is increasing, making them harder to predict and prepare for.
• Storm tracks are shifting, exposing new areas to risk and challenging existing assumptions about geographic exposure.
• In 2024, the Philippines experienced six landfalling typhoons in just 30 days, including super typhoon Man-Yi, which caused nearly half a billion dollars in damage.
• Forecasting agencies expect the 2025 season to follow typical activity trends, but climate-linked influences such as El Niño or La Niña conditions could escalate both frequency and severity.

Typhoon preparedness and organizational resilience planning

This checklist supports corporations and organizations in enhancing resilience before, during, and after typhoon events – particularly where operations, assets, or personnel span multiple geographic locations.

Preparedness planning and pre-typhoon actions

General organizational preparations

• Develop and disseminate a typhoon response and business continuity plan.
• Designate crisis management teams and site-specific response leads across all office locations.
• Confirm emergency communication channels are functional (e.g., SMS alerts, satellite phones, internal messaging platforms).
• Develop site-specific response plans for each office or facility, tailored to local hazard profiles and regulations.
• Conduct regular training and simulation exercises with crisis management and emergency response teams.
• Identify and prioritize critical business functions that must continue during a disruption and allocate resources accordingly.
• Ensure adequate emergency supplies are available at key sites, including food, water, medical kits, power banks, fuel, and critical documentation.
• Back up all business-critical data to secure cloud platforms with access controls and regional redundancy.
• Establish remote work protocols if physical access becomes restricted.
• Coordinate with local authorities and emergency services in high-risk regions.
• Assess insurance coverage for typhoon, flood, windstorm, and business interruption across impacted locations.
• Coordinate with insurers to understand pre-event documentation or evidence required for smooth claims processing.

Landslide hazard

• Review local hazard maps to identify offices and facilities in landslide-prone areas.
• Engage with property managers or landlords to verify that retaining structures and drainage systems are adequate.
• Relocate sensitive equipment and data servers away from vulnerable zones.
• Avoid initiating construction or development in known unstable areas.
• Install slope monitoring systems (e.g., tilt sensors, rain gauges) in high-risk areas.
• Pre-position emergency supplies, generators, andequipment above potential impact zones.
• Establish alternate access routes in case roads or driveways are blocked by debris.
• Train local facilities or security teams to recognize early signs of ground movement.

Windstorm hazard

• Reinforce windows, doors, roofs, and facade features infacilities located in high wind zones.
• Trim or remove overhanging branches and trees near company assets.
• Secure outdoor signage, furniture, and equipment that may become airborne.
• Commission structural audits to assess wind resistance of roofs, windows, signage, and facades.
• Install storm shutters or protective coverings on vulnerable windows and glass panels.
• Secure rooftop equipment such as HVAC units, antennas, and solar panels.
• Label and inventory outdoor assets and assign responsibility for securing them pre-typhoon.
• Arrange for rapid deployment contractors to assist with emergency boarding-up or repairs.

Flooding hazard

• Identify office locations and critical assets situated in flood-prone zones.
• Conduct flood risk mapping and overlay it with office and warehouse locations.
• Map out alternative supply chains and logistics routes in case of regional disruption.
• Install temporary or permanent flood protection (e.g., barriers, sandbags, raised thresholds).
• Elevate electrical systems, IT hardware, and inventory where feasible.
• Waterproof critical records, assets, and equipment, especially in archive or storage rooms.
• Pre-arrange storage of critical inventory or vehicles in elevated or off-site locations.
• Coordinate with facilities teams to inspect and clear stormwater drainage systems.
• Install sump pumps, backflow preventers, and water detection alarms in vulnerable zones.

Flash flood hazard – additional preparations

• Identify buildings at risk of sudden runoff or overwhelmed drainage systems.
• Ensure emergency lighting and alarms are functional and located above ground level.
• Map flash flood-prone commute routes for staff and advise on alternative paths.
• Stage evacuation drills specifically for rapid-onset flood scenarios.
• Assign a “rapid action team” at each site trained to shut down systems quickly and safely.

During a typhoon – immediate organizational actions

General measures

• Monitor regional weather forecasts and typhoon advisories from official sources (e.g., national meteorological agencies).
• Suspend non-essential operations in affected areas based on forecast severity.
• Ensure all personnel are accounted for and briefed on shelter-in-place or evacuation protocols.
• Maintain communication with key offices and response teams throughout the event – designate times for key staff members to call into conference calls for situation overviews.
• Switch off electrical devices during a power outage to prevent them from automatically turning back on before safety checks can be performed.
• Activate remote working contingencies for unaffected locations if cross-border coordination is impacted.
• If an evacuation is ordered, leave immediately and follow designated routes.
• Maintain an event log (timestamped) of key decisions, alerts, and actions for accountability and post-incident review.

Landslide risk areas

• Monitor for early warning indicators (e.g., structural cracks, shifting soil, water seepage).
• Relocate staff from high-risk offices to temporary safe zones if required.
• Relocate personnel from basement-level or hillside-facing rooms during periods of heavy rain.
• Temporarily suspend commuting to or from sites adjacent to unstable slopes or hilly terrain.
• Log and report any observed hazards to local emergency services.
• Maintain regular contact with staff located near known landslide zones for updates and safety checks.
• Monitor official updates and alert staff if landslide warnings are issued near offices or logistics routes.

Windstorm risk areas

• Shelter staff in interior rooms away from glass and unsecured fittings.
• Avoid the use of open flames in case of gas leaks or powerloss.
• Maintain real-time communication with site leads for incident updates.
• Continue real-time monitoring of wind speeds and structural stress points at affected facilities.
• Deploy pre-positioned staff only when conditions are confirmed safe for assessment (e.g., after peak winds).
• Use CCTV or remote monitoring systems to visually assess damage without putting people at risk.
• Place warning signage or cordon off areas near windows, glass partitions, or rooftop access.
• Refrain from sending staff outside to clear debris or check damage until wind warnings are lifted.

Flood risk areas

• Monitor real-time alerts from local authorities and flood warning systems.
• Shut off power and gas to affected properties when safe to do so.
• Assign staff to monitor internal water levels in basements, IT/server rooms, or loading bays.
• Suspend deliveries or facility access in case surrounding roads or infrastructure become submerged.
• Evacuate staff from facilities where floodwaters are rising if there is a safe route.
• Do not allow staff to walk or drive through rapidly moving water – even shallow water can be dangerous.
• Ensure continuity of key functions from unaffected regional hubs.

Flash flood (sudden-onset flooding)

• Initiate immediate site-wide lockdowns at affected facilities to prevent movement through flooded areas.
• Immediately relocate staff from basements, ground floors, or low-lying areas to higher floors.
• Re-deploy crisis communications to ensure staff across locations are aware of active flash flood alerts.
• Communicate with staff in field-based roles (e.g., logistics, maintenance, delivery) to halt all movement.
• Do not allow staff to walk or drive through rapidly moving water – even shallow water can be dangerous.
• Shut down electrical systems and isolate power sources in affected zones if safe to do so.
• Instruct facilities staff to avoid manholes, storm drains, and submerged equipment rooms.
• Activate internal alerting protocols for all facilities potentially in the flood path.
• If flash flooding is occurring at one site, assess potential knock-on effects for logistics, commuting routes, or downstream offices.
• Coordinate with local authorities for evacuation assistance if staff are trapped in flooded zones.

Post-typhoon recovery and long-term resilience

General recovery steps

• Wait for clearance from authorities before permitting re-entry into damaged facilities.
• Conduct rapid damage and safety assessments across all affected sites.
• Verify integrity of utility lines (gas, water, electricity)before restoring power or reopening buildings.
• Communicate openly with staff, stakeholders, and clients regarding recovery timelines.
• Establish a phased return-to-office plan, especially where transport or infrastructure is disrupted.
• Provide support to employees affected personally bythe disaster, including welfare checks and mental healthassistance.
• Reconnect and coordinate with suppliers, logistics partners, and local authorities to restore operations.
• Review and document lessons learned from the event for internal use and future planning.
• Conduct after-action reviews with crisis management teams at local and regional levels.
• Update emergency contact lists, protocols, and businesscontinuity plans based on event performance.
• Schedule a full inspection and certification of critical systems (electrical, structural, HVAC, fire safety).
• Assess reputational impact and prepare external messaging as needed for customers, partners, or media.
• Document all damage thoroughly for insurance claims.

Landslide recovery

• Inspect nearby slopes, access roads, and structural foundations for instability.
• Coordinate debris removal and site restoration activities.
• Update geohazard risk assessments and mitigation planning.
• Work with engineers or local authorities to assess long term risks of future landslides.

Windstorm recovery

• Identify and remove hazardous debris and verify the stability of roofs, signs, and external structures.
• Re-inspect all rooftop installations (solar panels, antennas, satellite dishes) for loose parts or failure risks.
• Resume operations in phases based on safety, structural integrity, and criticality.
• Engage contractors for structural repairs or reinforcement as required.

Flood recovery

• Conduct dewatering and sanitation of affected facilities.
• Replace or disinfect flood-damaged equipment and furnishings.
• Review the effectiveness of flood defense measures and update policies accordingly.
• Test and restore IT systems, backups, and network connectivity before full operational resumption.
• Engage environmental specialists to assess mold risk, air quality, and water contamination.
• Test internal air quality and HVAC systems – especially where flooding has impacted underground car parks or basements.