Climate in Hilo
Paradise awaits! However there are some realities about our tropical island you may want to know about before you come...
Big Island of Hawaiʻi
This island has the greatest concentration of climate zones in the world: 4 out of 5 Major climate zones and 8 out of 13 sub-zones. Which means if you don't like the weather, you don't have to drive far to get out of it.
However, be aware of the zone Hilo is in... Humid Tropical Climate (continuously wet).
Bear in mind according to U.S. Climate Data:
- Hilo has an average 126.69 inches of rainfall a year
- Seattle has an average of 37.13 inches of rainfall a year
When it rains, it pours. Peaking in March and November, Hilo receives 13-15 inches of precipitation in those months. Granted it dumps like a water bucket and moves on to sunshine, but bring a waterproof-yet-light-jacket, and a decent size umbrella.
Being classified as a Humid Tropical Climate...it is wonderful for the lungs and pores, not so wonderful for those who consistently style their hair.
"The relative humidity typically ranges from 58% (mildly humid) to 94% (very humid) over the course of the year, rarely dropping below 47% (comfortable) and reaching as high as 100% (very humid).
The air is driest around February 11, at which time the relative humidity drops below 64% (mildly humid) three days out of four; it is most humid around July 26, exceeding 91% (very humid) three days out of four."
Bear in mind there is a fairly consistent ocean breeze which is a wonderful deterrent to feeling overly sticky, however directly after rain a fair amount of that liquid re-evaporates and makes life muggy for an hour or so.
This element will mold and rot clothes, leather, left behind dishes, and many other surfaces which you wouldn't expect. Staying on top of laundry or other such chores is more important than in other locations as you may be in for a putrid surprise.
A wonderful thing about Hilo is its very narrow range of temperature.
In December the lowest average is 65°F/18°C, and in the height of the July it’s around 83°F/28°C. Due to this limited range, most homes deem air conditioning an expensive luxury, if they have it at all. And central heating simply does not exist in Hilo.
Bear in mind this is not the same throughout the island.
For instance, on the Kona side of the island it can get up into the 90s, whereas Hawaiʻi Volcanoes National Park lows in winter get down to the 49°F/9°C range and Mauna Kea is capable of snow. When most houses lack central air conditioning or heat this can pose a challenge.
Wikipedia defines Vog as:
"A form of air pollution that results when sulfur dioxide and other gases and particles emitted by an erupting volcano react with oxygen and moisture in the presence of sunlight. The word is a portmanteau of the words 'volcanic', 'smog', and 'fog'."
Basically the volcano is always active as we are still over the hotspot. When it hits the air it releases gas which is not friendly to asthma and other breathing conditions.
Vog can be seen in the comparison between two photos from Coconut Island area looking back toward Mauna Kea.
Depending on the wind currents it will push these clouds to different areas on the island. Sometimes Hilo is overcast with these orange tinted clouds and can only be pushed away by winds or brought down to the earth in slightly acidic rain.