Big Island

Vog on the Big Island

Around noon on Saturday a week ago, as my clients and I stopped for lunch during a day of looking at land parcels, a haze rolled in, masking the gorgeous views of Maui we’d enjoyed all morning and turning blue sky and ocean into a flat gray. Our characteristic trade winds had disappeared, and for a rare week North Kohala and the Hamakua Coast experienced “vog.”

If you are new to looking for real estate in Hawaii, the term “vog” may be new to you, even if you live in an area on the Mainland where you are well acquainted with “smog.” “Vog,” a term meaning “volcanic smog”, was coined in the early 1980’s as the longest recorded eruption of the Kilauea volcano took its current form. (I had to look it up, “smog” itself is a contraction of “smoke” and “fog” first used in the U.K. to describe the result of industrial air pollution mixing with moisture in the air). In a very similar way to the formation of smog from industrial or vehicular emissions on the Mainland, particulates spewing into the air from the volcano’s eruption create conditions that limit visibility and pose potential health hazards.

Vog not only affects the Big Island, where the source is located. Depending on the prevailing winds, I’ve had friends in Honolulu complain about vog obscuring the sunset, even as I watched a perfect one along the Kohala Coast, and other friends gave up their winter home property in Hana on Maui because of the husband’s respiratory difficulties.  Which brings me to the health effects.

In the past six months or so, sulfur dioxide (SO2) emissions have increased with Halema’uma’u crater adding to emissions from the Pu’u O’o vent. Typically you might notice itchy eyes, nose, throat or skin when sulfur dioxide levels are high. Children, and people with other respiratory conditions such as asthma, are considered at risk when emissions are elevated.

Although we were dismayed by the temporary loss of our clear skies and beautiful vistas in Kohala, from a health perspective we are less bothered than people living nearer the Volcano. Particulates can travel quite some distance, but the SO2 levels diminish as they travel away from the source. Similarly, our flower and produce growers in the Northern districts of the Big Island do not have nearly the problems with acid rain on their crops as those in the south Kona and Ka’u districts.

The southern districts are also more likely to have homes on rainwater catchment for their drinking water. Acid rain can affect the quality of catchment water. A USGS fact sheet is available describing vog and its effects in more detail and you can check on emissions levels at the source on the Volcanoes National Park website.

To put “vog” into perspective, my brother is here visiting and we were speculating about how the vog compared with the smog we experienced as kids in Colorado, especially when winter temperature inversions trapped auto emissions in the Denver metropolitan area. The government AirNow website is a resource to check the air quality where you live.

Today looks pretty good all over the U.S. including Hawaii. The only alerts are in Bakersfield and Fresno, California, where ozone looks to be the problem. For detailed information specific to the Big Island, Oahu and Maui, check out Hawaii daily air quality data.

You can also download a brochure prepared by the County of Hawaii on Emissions from Kilauea Volcano at

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June 1, 2009

I was on the Big Island recently and every one says the vog was really bad while I was there. I didn’t seem to notice anything too bad.


July 28, 2009

We were on the Big Island back in mid-May and definitely saw and smelled the “vog.” It seemed worse on the southwest side of the island, where a definite sulfur smell was in the air, although we didn’t notice any burning of our eyes, noses, etc. I am wondering if anyone has general statistics on which parts of the Big Island are more frequently affected by the vog? We’re considering a move there, but of course where we would consider buying is impacted by this phenomenon. Thanks!

Beth Thoma Robinson, R(S)

July 28, 2009

Hi Chris,
Did you take a look at the “Hawaii daily air quality” link I provided in my post? It takes a few moments to load, but then you can pull “Big Island” from the drop-down menu and monitor it. For example, today it says particulates are high in Kona but SO2 low there; Pahala has high SO2 but low particulates. You are exactly right that the southwest side of the island typically gets the most, but that depends on the winds. The downloadable brochure I mention is also a good independent source.

Beyond that, it is generally a good idea to talk to people about their experience in different areas that otherwise meet your criteria!

Bob Nelson

September 2, 2009

I am planning to move to either Maui or the Big Island in a year or two. When I became aware of the VOG problem, especially on the Big Island, I began studying the wind patterns on the island. I also look at webcams on a daily basis to evaluate ‘haze’ levels between Kona, Waikiloa and Kohala. It appears to me that Kohala would be the area on the Big Island where VOG would be less prevalent. The article seems to confirm this. Thank you.

Scott Riggs

September 26, 2012

I have recently been looking at the south end of the big island,Specifically The Kahuku Ranch that is for sale,I am wondering now about the air quality there and the water quality..
Question? Does anyone have any information about that area? as my trip I am planning will have my kids & grandkids with me when I come out & I am hoping to persuade my wife to warm up to a move to Hawaii as she is afraid of everything,Volcanoes etc. She grew up and has always lived in the Ozarks of Missouri..

Beth Thoma Robinson R(B)

September 26, 2012

Hi Scott, I emailed you privately with the information you requested on the Ranch for sale and the area.

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