Air Conditioning

Will Rain Damage a Window Air Conditioner?

Will Rain Damage a Window Air Conditioner


Summers in certain regions can bring hot and humid conditions, often accompanied by frequent summer storms. In such climates, air conditioners become essential. One common concern is will rain damage a window air conditioner? or whether it is safe to run a window  ac during rainy days. To address this question, we consulted with an air conditioning engineer to provide clarity on the matter.

Is Rain Harmful to Window Air Conditioners?

Contrary to concerns, rain does not pose a threat to window air conditioners. These units are designed with sealed electrical components to prevent water damage. Light rain will not affect the performance of the air conditioner, as the dry parts are adequately protected. However, certain precautions should be taken to ensure the unit’s longevity and efficiency.

Potential Issues:

While light rain is harmless, strong winds during a storm can lead to debris getting entangled in the air conditioner’s fan, potentially causing problems. Following a heavy storm, it is advisable to inspect the unit promptly to ensure it is free from leaves, sticks, or other debris. Standing water is another consideration, as it may cause electrical components to short. If the unit is submerged, it is crucial to have an HVAC technician inspect it before restarting.

Protecting Your Air Conditioner:

To shield window air conditioners from debris, some individuals use covers. However, it is essential to use purpose-designed covers, as makeshift solutions like plastic sheets or trash bags can trap moisture, leading to rust and mold. These covers are primarily aimed at preventing leaves and other debris from clogging the fan, rather than protecting against rain.

Sealing Gaps in the Window:

Proper installation is crucial to prevent rainwater from leaking through gaps around the window air conditioner. Using rope caulking to fill small holes and gaps can be effective. This removable and sometimes reusable material helps maintain a tight seal, preventing both water leaks and energy inefficiency due to air leaks.

Maintenance Tips:

While window air conditioners are less complex than whole-house systems, they still require regular maintenance. Cleaning the filter monthly, especially during periods of frequent use, is recommended. Additionally, annual maintenance tasks include cleaning the fins and fan, inspecting and emptying the drain pan, and straightening any bent fins.


In conclusion, running a window air conditioner during light rain is generally safe, given proper installation and maintenance. The key is to use purpose-designed covers to protect against debris and ensure that the unit is free from obstructions following a storm. Regular maintenance practices will contribute to the longevity and efficiency of your window air conditioner.

Disclosure: We may get commissions for purchases made through links in this post.

About the author


I am Ben , a seasoned HVAC specialist with over 6 of experience in the HVAC industry. I holds HVAC Certification and has a proven track record in providing expert advice on HVAC systems.

Leave a Comment