Watering the Garden Isle

It has been raining here on Kauaʻi - heavily on the north shore, and a bit more than usual here on the south side as well where it is usually much drier.
When you visit Kauaʻi, especially in winter months (November through March) you should expect some precipitation.

At right is the Lihue seasonal weather which is a kind of an average for the island. Weather on the island roughly breaks down into north/south areas where north is the windward or more precisely the northeast half of the island, and south the south and west. The predominant trade winds typically come from the northeast so incoming moisture gets deposited first on that side, then pushed up the mountain to rain on the top, and then whatever makes it over the top or around the sides sometimes rains on the far side. That said it does often rain up mountain on the south side in Kalaheo and Lawai areas, and when we have Kona winds (from the south and west) then the west side gets most of the rain.

It is not unusual for the north shore to be impacted by heavy rain closing the road (the only way in or out of the area) when the Hanalei river overflows its banks. Missing your flight back home could be among the least of your concerns if you are in Hanalei or Haena when the big rains come. You can check the height of a few rivers here.

Average daily rainfall [tabular data]

Kokeʻe has some of the best hiking to be found anywhere but in winter it can be wet. At 4000 feet it is always cooler than most of the rest of the island and beaches. See average seasonal weather at left: rainiest in the winter and warming in the summer. Depending on your style and level of experience some people don't mind tromping through the mud - not just the mess but slipping can be a serious problem. Any time heavy rains are possible it's important to avoid streams and gullies that can flash flood.

To avoid the mud I suggest giving it at least one mostly sunny day to dry out (or more after heavy rains up there). Alternatively hiking lower down in Waimea canyon is usually a lot drier most days.

On a rainy day the tourist options are limited but here are a few ideas.

• Get wet: snorkeling or surfing you get wet any way (of course, water safety comes first)
• Visit the Kauai Museum in downtown Lihue
• Go for a drive around the island: it may be drier on the other side (check windward vs. leeward)
• See whatʻs playing at the historic Waimea movie theater (a little different movie experience)
• Take a rest from your vacation

Average daily rainfall [tabular data]

Not that anybody actually goes there but I tracked down some weather data from Mount Waiʻaleʻale, one of the rainiest spots on the planet. Kauaʻi's 5000 foot peaks are almost always enshrouded in clouds and as the graph makes clear, it rains there regularly an inch a day or so.

Most "Kauaʻi in 25 words or less" summaries mention this remarkable rainfall yet it has little to nothing to do with the weather we experience on the island. First of all, unless you manage to tag along on the rare helicopter visits to check the weather monitoring equipment up there, the place is virtually inaccessible. Not only the old knowledge of trails but probably the trails themselves have vanished in modern times. Kauaʻi itself is an old volcano in the process of breaking down and that makes for unstable terrain - especially where it gets socked with rain - and makes steep area unclimbable due to the crumbling makeup of the land.

It looks like the wettest times up there are spring, summer, and fall. Perhaps in winter when the lowlands see the most rain that drains off a little of what would otherwise make rain on top.

• Hawaii state rain summary map