Heating & Cooling · West
Cost to run a dehumidifier in Hawaii
At Hawaii’s average residential rate of 52.00¢ per kWh, a dehumidifier drawing 500W for 12 hours a day costs about $56.98 a month. Change the numbers below to match how you actually use yours.
Cooling demand in Hawaii is steady year-round rather than seasonal, so a dehumidifier here accumulates runtime every month. Combined with the highest electricity rate in the country, that makes this one of the most expensive places in the US to run this appliance.
Quick answer
Based on 500W at a 60% duty cycle (this equipment cycles on and off rather than drawing full power continuously) and 52.00¢/kWh, the Hawaii average for May 2026.
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— per year
Why the cost differs in Hawaii
Hawaii has the 51st cheapest residential electricity of the 51 US states and territories we track, at 52.00¢ per kWh against a national average of 18.44¢. That is +182.0% compared with the national figure. Hawaii is the most expensive electricity market in the United States by a wide margin, and the cause is geographic rather than regulatory: no pipeline or transmission line reaches the islands, so most generation burns imported petroleum priced on world markets. Each island runs its own grid with no mainland backup. Cooling demand is steady year-round, and there is essentially no heating load.
For this appliance specifically, the difference works out to an extra $441 a year over what the same dehumidifier would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $683 a year; in Idaho it would cost $162. That spread of $521 is entirely down to location.
That is about 13% of a typical Hawaii household's annual electricity bill from this one appliance, which is enough to be worth optimising.
Because Hawaii is among the most expensive states for electricity, efficiency upgrades pay back faster here than almost anywhere. A more efficient dehumidifier that saves a given number of kilowatt-hours saves noticeably more money in Hawaii than the same upgrade would in a cheap-power state.
Retail service in Hawaii is regulated, so most households pay a tariff set through state rate cases rather than a shopped rate. The state average is a reasonable proxy, though your utility's specific tariff still varies.
| Location | Rate | Per month | Per year |
|---|---|---|---|
| Hawaii this page | 52.00¢ | $56.98 | $683 |
| US average | 18.44¢ | $20.21 | $242 |
| Idaho cheapest state | 12.35¢ | $13.53 | $162 |
| Hawaii most expensive | 52.00¢ | $56.98 | $683 |
Hawaii electricity rate trend
Rates in Hawaii have moved from 40.96¢ to 52.00¢ per kWh over the last twelve months of published data. Nationally, residential rates rose about 6.2% year over year.
2025-06 to 2026-05 · cents per kWh
About running a dehumidifier
Dehumidifiers run longest in exactly the humid weather when they are most needed, so real-world cost is usually higher than people expect. They also add heat to the room, slightly increasing cooling load.
What actually changes the cost
- Nameplate wattage is not running cost. This dehumidifier draws about 500W when active, but cycles roughly 60% of the time it is switched on, so effective consumption is near 300W.
- Models vary widely, from about 300W to 800W. Check the nameplate on your own unit rather than assuming an average, because the spread is more than 2x.
- Insulation and air sealing reduce runtime, which lowers cost more reliably than adjusting the thermostat by a degree.
- Because this runs continuously, small wattage differences between models compound into large annual differences.
- If your utility offers time-of-use pricing, shifting this load off-peak can cut its cost substantially without using any less energy.
How we worked this out
The arithmetic is simple and we would rather show it than hide it. Divide watts by 1,000 to get kilowatts, multiply by hours of use and by the duty cycle to get kilowatt-hours, then multiply by your rate:
500W ÷ 1000 × 12h × 60% = 3.600 kWh/day × 52.00¢ = $1.872 per day
One honest caveat: Hawaii’s figure is a state average published by the EIA. Your own utility’s tariff, any time-of-use pricing, fixed monthly service charges and local taxes all shift the real number. Put your actual per-kWh rate into the calculator above for a figure that reflects your bill.
Questions about dehumidifier running costs
How many watts does a dehumidifier use?
A typical dehumidifier draws about 500 watts while running, with most models falling between 300W and 800W. Check the nameplate label or manual for your specific unit - the range is wide enough that averages can mislead.
How much electricity does a dehumidifier use per day?
At around 12 hours of use a day and a 60% duty cycle, that works out to roughly 3.6 kWh per day, or about 108 kWh a month. Your actual figure depends on your usage and model.
Why does the cost differ so much between states?
Residential electricity rates across the US range from about 12.35 cents per kWh in North Dakota to 46.62 cents in Hawaii - nearly a fourfold difference. The same dehumidifier, used identically, therefore costs almost four times as much to run in the most expensive state as in the cheapest.
Is it cheaper to run a dehumidifier at night?
Only if you are on a time-of-use or variable tariff. On a flat rate, the time of day makes no difference to cost. If you are on time-of-use pricing, off-peak hours are typically materially cheaper, and shifting this load can reduce its cost without reducing usage.