Reasons You Need a Humidifier in Seattle

If you are planning to move to Seattle, you might need to know how dry or humid it is there. This will determine the kinds of indoor appliances, such as air conditioners, humidifiers and dehumidifiers that you may need.

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So do you need a humidifier in Seattle? You need to keep your indoor humidity between 30 and 50%. The average daily temperature in the city is 8.8°C (48 °F). This is quite low. Therefore, you have to crank up the heat, which in turn sucks the moisture out of your indoor air. Many homes in Seattle are not equipped with whole-house humidifiers, so you would need to buy a portable unit. 

The work of a humidifier is to add humidity to your indoor air. Therefore, if you live in some of the coldest cities in the USA, you do need this appliance.

The reason for this is that you almost have to have the heat running daily and nightly. Therefore, the humidity level drops below the recommended average.

What is the coldest month in Seattle?

Now that we have established the need to crank up the humidity during the coldest months. In this city, January is the coldest month, with temperatures going as low as 2°C (36°F). That is low! The heat has to be on high, and that is bad news for indoor humidity.

The month of February is almost as cold, and the fall months are just a little bit less cold. So, you need to run a heater for 5 to 6 months in Seattle.

August is the warmest month in this city, with an average daily temperature of 23.8°C/74.9°F. That is good, but it is not too high either.

Does it get humid in Seattle?

Why is it so cold in Seattle? Experts say the reason for this is the closeness to the Pacific Ocean. In any case, this city is cooler than many cities in 48 states, so yes, we can say that it is cold.

Seattle is one of the most humid places in the USA. This therefore beats the reason why you would need to humidify the air rather than use a dehumidifier.

However, the fact is that the air being humid outdoors does not mean it will be humid inside the house. When you have low temperatures and high humidity, the air can become freezing, you know, much like having rain and low temperatures combined.

Therefore, inside your home, you will have to turn on the heat. This dries the air. Therefore, once or twice a day, you may have to turn on your humidifier. This will inject some mist into the air.

Most of the time, you will find it easy to raise the humidity to 50%. With a humidistat, the appliance can turn on automatically when humidity falls below 30% and switch off when it rises above 50%.

How to tell if you need a humidifier in Seattle

Even if you are not entirely sure that you need this appliance, here are some things to watch out for:

  • You experience colds starting November to early March
  • The hygrometer shows the temperature to be below 30%
  • You find that you have to turn on the heat frequently
  • Your family starts experiencing dry skin
  • Your indoor plants seem to be dehydrated


Do you need a humidifier in Seattle? You would think you didn’t because of the high humidity. However, the temperature is what we would consider “cool” most months of the year. Therefore, you need an appliance that can increase your indoor humidity.

You can also read our article on how to stop humidifier white dust.