Japan’s rainy season brings prolonged rainfall and high humidity, making it a challenging time for vacation rental operators when it comes to cleaning and maintaining properties. To ensure guests enjoy a comfortable stay, it’s essential to properly address the humidity, mold, and odor issues that are unique to this season. Understanding the key points to focus on during this particularly damp time of year—compared to other seasons—can help prevent property deterioration and have a positive impact on your review ratings.

This article focuses on “5 Things to Watch Out for When Cleaning Vacation Rentals During the Rainy Season,” offering detailed, practical tips on mold prevention, ventilation, linen and towel management, and more. Please use this as a reference to minimize the troubles and burdens unique to the rainy season, helping you achieve stable long-term revenue and improved guest satisfaction.

1. Frequent Ventilation to Prevent Humidity and Mold

During the rainy season, humidity levels throughout the room rise significantly. If left unaddressed, this not only causes mold growth and odors but can also cause significant damage to furniture and appliances. The first line of defense is “frequent ventilation.”

1-1. Combining Natural and Mechanical Ventilation

Even during continuous rainfall, there are often brief moments when the rain lets up due to changes in temperature and atmospheric pressure. Simply opening windows to exchange the air during these moments can help lower the room’s humidity. Additionally, when owners or cleaning staff are present, using exhaust fans and circulators together to forcibly circulate the air is also effective.

1-2. Make “Ventilation First” a Cleaning Rule

When cleaning staff arrive, establishing a habit of “ventilating first”—opening windows and turning on exhaust fans immediately—helps expel humidity and the sources of mold that have built up indoors at an early stage. Before using aroma diffusers or deodorizers, it’s important to first release the stale air outside.

2. Thorough Mold Prevention

In humid environments, mold can develop extremely quickly. Once mold spreads, it not only creates issues with appearance and odor but can also pose risks of allergies and health problems. During the rainy season, be sure to focus on checking areas prone to mold growth and take early preventive measures.

2-1. Thorough Cleaning of Bathrooms and Water Areas

Bathrooms, sinks, toilets, and other water-related areas are the most prone to mold growth. In particular, tile grout, rubber seals, and areas around drains are susceptible to small patches of black mold. When cleaning, use mold removers and bleach to thoroughly eliminate any buildup. Additionally, finishing with an anti-mold spray can help prevent recurrence.

2-2. Check the Air Conditioner and Its Filters

The interior of air conditioners can easily become an environment with high humidity and temperature, making it a breeding ground for mold and bacteria. It’s advisable to inspect the air conditioner before the rainy season begins and either clean the filters yourself or hire a professional cleaning service. If there’s a musty odor, it can cause significant discomfort for guests, so it’s important to prevent problems before the unit is put into use.

2-3. Don’t Forget Behind Furniture and Closets

Areas that are surprisingly easy to overlook—such as the backs of large furniture pieces or the depths of closets—are places that don’t often get thoroughly cleaned. Because air circulation is poor and humidity tends to accumulate in these spots, mold is prone to develop there during the rainy season. Where possible, it’s effective to move furniture slightly away from walls to create gaps for airflow, or to place dehumidifying agents or charcoal in these areas.

3. Linen and Towel Management

Linens and towels come into direct contact with guests’ skin, and if not managed properly during the rainy season, they can easily develop a “musty” or “bacterial” smell. Providing guests with odorous towels or sheets can significantly impact your review ratings, so extra care is needed.

3-1. A Laundry System That Ensures Complete Drying

Since outdoor drying is difficult during the rainy season, it’s essential to make full use of dryers and indoor drying dehumidifiers to ensure items are “completely dry.” If linens are stored while still slightly damp, bacteria can multiply within a day, leading to unpleasant odors. It’s a good idea to establish a rule for laundry staff to “check for odors after the drying process is complete.”

3-2. Frequent Inventory Rotation

Properties that store large quantities of towels and sheets are prone to humidity buildup in storage areas or closets during the rainy season, which can lead to mold and odors. Rotate inventory regularly, bringing older stock to the front for use, to prevent items from being left unused for extended periods. Placing dehumidifying agents or charcoal in storage areas and monitoring the humidity levels there is also effective.

3-3. Additional Towel Options for Guests

Long-term stays, families, and international guests may use towels more frequently. Since drying times are delayed during the rainy season, preparing additional towels can become challenging. By establishing rules—such as “additional towels are available for a fee” or “free towel replacement every X days for long-term stays”—and communicating these to guests, you can strike a balance between operational costs and guest satisfaction.

4. Supporting Ventilation and Dehumidification

Setting up equipment and guidelines so that guests can properly dehumidify and ventilate the space while they’re out or during the night helps reduce the likelihood of problems arising.

4-1. Making Use of Dehumidifiers and Air Conditioner Dry Modes

To encourage guests to actively use the room’s dehumidifying features, prepare an instruction manual or simple guide. Making it available in English and other languages ensures it’s easy to understand for international guests as well. The air conditioner’s dehumidify (dry) mode is particularly useful, but it’s thoughtful to include a note cautioning against overcooling the room.

4-2. Setting Up Circulators or Fans

Depending on the property’s layout, there may be areas with poor air circulation. Placing circulators or fans in these spots prevents humid air from stagnating and promotes ventilation throughout the room. During periods when summer overlaps with the rainy season, this can also improve air conditioning efficiency, helping to reduce electricity costs.

4-3. Suggesting Times to “Open the Windows Slightly”

Since Japan’s rainy season includes periods when the rain stops, encouraging guests to open their windows briefly after waking up or before heading out promotes natural ventilation. Some properties may not be able to open windows wide due to storm shutters or eaves, so it’s helpful to explain that “even opening the window just a few centimeters—enough to avoid rain coming in—can make a difference.”

5. Preparing for Trouble and Communicating with Guests

Even with thorough rainy season preparations in place, unexpected prolonged rain or guest oversights can still lead to humidity-related issues. To handle such situations calmly when they arise, it’s important to establish a communication system and guidelines in advance.

5-1. Providing Emergency Contact Information

When guests encounter an urgent issue—such as “the room smells musty,” “there’s water leaking from the air conditioner,” or “I need to borrow a cloth”—make sure there’s a way for them to reach out immediately. Even if you can’t offer full 24-hour support via phone or messaging apps, clearly stating that you’ll respond promptly can provide guests with peace of mind.

5-2. Offering Simple Troubleshooting Guides

Including simple solutions in your guidebook—such as how to handle a wet bath mat or towel, or how to clean the air conditioner filter—allows guests to address certain situations themselves, regardless of the time of day. For example, you might include instructions like, “If you notice a spot that looks like it might develop mold, please use this spray.”

5-3. Attentive Follow-Up

If a problem occurs and a guest expresses dissatisfaction, it’s crucial to apologize promptly and communicate the steps you’re taking to resolve it. Respond flexibly depending on the situation—whether that means dispatching additional cleaning staff or, if possible, offering a room change. Keep in mind that during the rainy season, ongoing bad weather can cause issues to drag on, so maintaining consistent communication with guests is key to a successful resolution.

Trust Stay Buddy Co., Ltd. with Your Rainy Season Vacation Rental Cleaning

In this article, we’ve covered “5 Things to Watch Out for When Cleaning Vacation Rentals During the Rainy Season,” offering detailed insights on humidity and mold prevention, linen management, guest communication, and more. This period of continuous rain and high humidity is a challenging season for vacation rental operators and cleaning staff alike—but by thoroughly implementing proactive measures and consistent daily care, you can prevent mold and odor-related issues and maintain high guest satisfaction.

If you’re thinking, “I want to leave rainy season-related cleaning and management to the professionals,” or “I’d like a one-stop solution for everything from guest support to trouble management,” please contact Stay Buddy Co., Ltd. Drawing on our expertise and proven track record, we provide comprehensive support—from property maintenance to guest communication and review improvement. We’re here to help you resolve the unique challenges of the rainy season while delivering a comfortable stay experience for your guests.