Kauai Weather Guide

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Poipu, Kauai

Weather patterns can be an important part of deciding when to plan your Kauai vacation. We want to provide you with plenty of Kauai weather data to help you make an informed decision.

Before we dive into the details, bear in mind that weather history is a fairly descent predictor of future weather. It’s the best tool we have. However, an unusual weather pattern could easily change the actual weather experience. That is true of any destination, not just Kauai.

Average Kauai Temperatures

Let’s start with the high and low temperatures. The following graph shows the average monthly high and low temperatures based on weather data collected at the Kauai airport in Lihue. Lihue is a town that’s very close to sea level and is therefore fairly representative for all the Kauai beach resorts. As you can see from the chart, Kauai’s weather is pleasantly warm year-round. Even in the coolest month of January, daytime highs average 78 F and the evening lows dip to 65 F. August is the warmest month with daytime highs averaging 85 F and cooling off to 75 F in the nighttime. (To convert temperatures to Celcius, use this link.)

Kauai year round average high and low temperatures

Kauai temperature data sourced from Weather.com

Kauai Rainfall Data

Before we look at Kauai rainfall details, we want to highlight one very interesting pattern about rain in Hawaii — more rain falls overnight than during daytime hours. Rain showers are usually brief. So, keep that in mind as you are considering this data.

Even though winter months tend to be a little wetter, we wouldn’t hesitate to book a Hawaii vacation in the winter. In fact, we tend to go to Hawaii quite often in the winter and it’s been very rare that we’ve encountered rain. We’ve never had a full day that was a complete rainout.

Rain in Hawaii brings some benefits that we tourists enjoy. Rain makes the pretty waterfalls flow. (Note that some waterfalls dry up or are only a trickle after a dry summer.) The rain makes Hawaii’s delicious produce grow and the flowers bloom.

If you have further concerns about rain, read our article — will it rain on my Hawaii vacation?

The following chart shows the average monthly rainfall levels based on data collected at Kauai’s main airport in Lihue. With 2.3 inches of rain or less, the driest months range from April through September. The rainiest month is December at 5.2 inches of rain.

Kauai Average Rainfall by month

Lihue, Kauai monthly average rainfall graph created by Go Visit Hawaii with data sourced from Weather.com

Another point to note about the above rainfall chart is that the significant increase in rainfall between February and March is partially due to the fact that March has more days than February. When we further investigated it, rainfall levels in March were still slightly higher in March as compared to February, which is not as dramatic as the chart appears at first glance. 

As you are reviewing rainfall levels throughout the year, another aspect to consider are the micro-climates on the island. Some areas are drier than others. The following map shows the annual rainfall by area.

kauai rainfall map

Giambelluca, T.W., Q. Chen, A.G. Frazier, J.P. Price, Y.-L. Chen, P.-S. Chu, J.K. Eischeid, and D.M. Delparte, 2013: Online Rainfall Atlas of Hawai‘i. Bull. Amer. Meteor. Soc. 94, 313-316, doi: 10.1175/BAMS-D-11-00228.1

Additionally, take a look at the following Bing bird’s eye view map of the island. The darker greener areas experience the most rainfall.

From these two maps, take notice that the popular resort area of Poipu is the driest region, followed by the east side towns of Kapaa and Lihue where many hotels and vacation rentals are. On the North Shore, Princeville is a popular destination with vacation accommodations even though the region gets more than twice the amount of rain as the east and south resort areas. Does that mean that if you choose to stay in Princeville you’ll constantly experience rain? That’s highly unlikely! Remember that most rain falls overnight and rain showers are usually short. That all being said, if you are planning a vacation during a month with above average rainfall levels, it might be a good idea to stay in east or south resort regions to minimize rain. There are no guarantees for better weather, but based on history and probability it’s a safer bet.

If you are torn between where to stay on Kauai, consider splitting your time between the different climates. See our post on two different vacation experiences on the same Hawaiian Island.

In addition to the Kauai rainfall data, we want to share some of our personal experiences with Kauai weather. We’ve visited Kauai in the months of February, April, May and October. In all those visits, we’ve only experienced one rainy day that ruined our plans. Ironically, that rainy day was in one of the driest months — May. We were also staying in one of the driest regions — Poipu.

Ocean Temperature around Kauai

Per GoHawaii, ocean temperatures range from 71 degrees to approximately 81 degrees. The colder temps are in the late winter months, while the higher temps are in the late summer and early autumn months. For more data see this link.

Humidity in Kauai

Per the data on this page, the average humidity is in the low to mid 70%. Most people will agree that 70% is pretty high humidity. Thankfully the prevailing tradewinds from the northeast, keep you comfortable despite the humidity. Occasionally, Kona winds from the southwest make the atmosphere feel hot and sticky.

To keep more comfortable in humid weather, we recommend that you stay in a place that has ample air conditioning. We spent a couple of nights in a Poipu condo without air conditioning one April. With a ceiling fan on, by late night, we’d start to feel comfortable in the condo. We vowed then to always stay in accommodations with air conditioning.

Wear light, breathable clothing to help you feel more comfortable in the Kauai humidity.

Hurricanes in Kauai

The last hurricane, Iniki, that hit Kauai and caused any major damage was in 1992. Hurricane season in Kauai, which runs from June through November, is usually quiet, however 2015 has been an unusually busy season for tropical storms.

Have you been to Kauai? What time of year did you go and what was your experience with the weather?


About Sheila Beal

Sheila Beal is the founder and editor of Go Visit Hawaii. You can connect with Sheila Beal on Twitter, Go Visit Hawaii on Facebook, or Sheila Beal on Google+.

10 comments

  1. I was wondering if there is an iPhone app for govisithawaii.com? I currently use an iPhone 6.

    • Hi Bruce and thanks for your question. We don’t have an app, but the entire site is mobile friendly. You could create bookmark of GoVisitHawaii.com on your iPhone and access the site from there. Hope that helps!

  2. Thanks! This really helps.

    Mahalo

  3. what a helpful site!! love it!!

  4. We are in Kauai may 24th through June .6th. Looking at the weather report. I only see one day that says it’s sunny. I realize in that you say the rain is brief but to me it looks like major rain storms the whole time we are there. are we ready to much into the weather report? Can we expect more sunny days than what it is showing?

    • We have no way of knowing how much sun and how much rain you’ll experience….no one knows, not even the weather forecasters.

      The weather can be very changeable and very different from one side of the island to the other.

      At the end of your vacation, please let us know what sort of weather you encountered.

  5. HI

    I am planning vacations in Kauai from 10th December to 18th December.
    Weather forecast is showing rainy weather all these days. Is it a good idea to postpone the vacation plan in Kauai?

    • We can’t tell you if it’s a good idea to postpone or not.

      Anecdotally, we went to Kauai in September. The forecast showed showers every day. We only experienced a couple of very brief passing showers and the rest of our time was free of rain.

  6. We have vacationed in Kaua’i 6 times in September. The skies are usually overcast and a little rain falls most days but is short lived. It still is a paaradise to visit. We like the Hula festival in September.

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