Healthy Sunlight in Hawaii

Measuring Light in Hawaii

After reading studies about the health benefits of sunlight and reports that world-wide pollution is blocking sunlight in the northern hemisphere, we wondered how bright the sun is in Hawaii?  

To find out we ordered a digital light meter (Dr Meter) to see how much light we are getting inside our home and on our walks.  Is the sunlight as bright as it seems?

Researchers at Northwestern University’s Feinberg School of Medicine found that exposure to light was correlated to BMI (Body Mass Index).  The key was to bask in light of at least 500 Lux (a unit of light measurement) and the best time for the exposure was early in the day. Every hour the light exposure was delayed, BMI rose by 1.28 points.  

With new our light meter we measured the Lux during our early morning walk at 6:20 in the morning.   The sun was just on the horizon so were surprised to see the readings ranging from 800 to 3000 Lux.  Later in the morning, sitting on our couch next to the open windows, the readings ranged from 500 to 600 Lux.  At noon, on a cloudless day with the sunlight directly overhead, we measured over 140,000 Lux.  In Kona, even on a morning with moderate Vog (Volcanic smog), the reading was still 70,000 Lux.

Measuring Lux at sunset in Hawaii

At 5:30PM, with the sun low in the sky and cloud cover, the light was still over 3000 Lux on the beach.  

3250 Lux on the beach at 5:30PM

We were expecting higher light levels than on the mainland since Hawaii is the only state south of the Tropic of Cancer.  But the extremely high noon Lux measurements confirms Hawaii is giving us an incredible amount of healthy sunlight. 

As the days get shorter and we head into winter, we are curious to see how much the light levels will change in Hawaii.