Is it Humid in Hawaii?

If you are Hawaii-bound for the very first time, it's natural to wonder what kind of weather to expect. Heat and humidity levels dictate not just what to pack but also what kind of activities are comfortable during your trip to the Hawaiian Islands. Of course, even in Hawaii heat and relative humidity vary from month to month. So is it uncomfortably humid in Hawaii? The best answer is: it depends. Read up about the different factors that control comfort level in the aloha state.

The state of Hawaii includes seven separate islands of different sizes: Kauai, Oahu, Molokai, Lanai, Maui, and the island of Hawaiʻi, and each may have a slightly different climate. In addition, these are volcanic islands, and some have high volcanic peaks where temperature drops as sea level rises. The trade wind breezes pass through the area as well, cooling one side of the island and raising temperatures and humidity on the other.

Although all of these considerations impact Hawaii's climate, average weather and humidity figures still count. In general, given its place in the tropics, the length of Hawaiian days doesn't vary in the same way day length changes in other states. The longest day is about 13 hours, the shortest about 11 hours. Because of this, seasonal temperature swings are also minimal.

In fact, Hawaii weather is very consistent. The state's two seasons are summer, lasting from May to October, and winter, November through April. In the summer months, the average temperature at sea level is 85 degrees F during the day, while in winter, the average daytime temperature is 78 degrees F. At night, these temperatures drop by about 10 degrees. Winter months also get more rain, but most of it falls in upper altitudes and on the north shore, or windward side of the islands. The city of Hilo on the big island of Hawai’i recieves over 130 inches of precipitation a year, making it one of the wettest cities in the world. All of this is largely why the more touristy areas tend to be on southern coasts, or the leeward side of the islands. Cities like Waikiki and Kona tend to be drier year round, which is better for hotels and tourist services that center around outdoor activities.

"Muggy "is an imprecise word that pretty much everyone understands to mean uncomfortably high humidity. Humidity can be high whether it's hot or cold outside, but you don't feel it as much in cool weather since your sweat actually cools your skin. If you are used to the “muggy” heat of Alaska or Alabama, that’s not sometyhing you’ll find in these climate zones. It's no accident that the expression "hot and muggy" is used far more often than "cold and muggy."

Humidity is described in a percentage. Think of the air as a sponge absorbing water vapor. When it has absorbed as much as it possibly can, humidity is 100 percent.

Average humidity in Hawaii is highest in the morning and decreases as the day wears on. For example, in Lihue, Kauai, in January, the humidity level is 81 percent, while in mid-afternoon it is 66 percent. In Honolulu in July, the warmest time of year, the morning humidity level is 67 percent while in the afternoon, it is 51 percent.

Does Hawaii feel muggy? Sometimes it does at sea level if you aren't swimming or playing in the ocean, and if the ocean temperatures are warmer. As you travel up in elevation, humidity drops. And the trade winds often keep humidity from becoming uncomfortable. Many people describe Hawaii as having perfect weather.

Even in winter, you won't need to focus on clothing you can layer when you go to Hawaii. Bring clothes made of breathable, lightweight fabrics. Include shorts, sundresses and sleeveless tops, as well as jeans and tee-shirts. You may want a nice outfit for going out to dinner. Sandals and sneakers will probably see you through unless you are doing serious hiking. In that case, bring hiking boots.

Just-in-case items to bring: a light raincoat (a must if you visit in rainy season or tropical storm) and a jacket in case temperatures drop. But leave the heavy jackets and sweaters at home.