How much it costs to run a hot tub in Idaho
Short answer
Keeping a typical 6- to 7-seat hot tub hot in Idaho costs about $20 a month, or $237 a year, at the state's average rate of 12.96¢ per kWh. The figure uses the median tub's measured standby draw of 209 W. With January averaging 25.1°F in Idaho, winter bills run above it.
| 2 to 3 seats | $14 | $10/moCaldera Spas Aventine |
|---|---|---|
| 4 to 5 seats | $17 | $11/moHot Spring Aptos |
| 6 to 7 seats | $20 | $12/moNordic Hot Tubs Crown |
| 8 or more seats | $23 | $14/moJacuzzi J509 |
| Swim spa | $41 | — |
How does Idaho's electricity rate compare?
Homes in Idaho pay 12.96¢ per kWh on average, 29% less than the US average of 18.19¢: the 3rd-lowest rate of the 50 states and DC.
For the median 6- to 7-seater that is $8 a month less than the same tub at the US average, about $96 a year.
The nearest rates to Idaho's are Nebraska (12.90¢) and Utah (13.16¢). EIA's figure averages every utility and month in the state. The rate on your own bill, delivery charges included, is the one to use, and the calculator on hot tub running cost takes it.
Does winter in Idaho raise the cost?
Yes. Idaho's January averages 25.1°F, below freezing and the 14th-coldest of the 51. The coldest January in NOAA's 1991–2020 record, 2017, averaged 18.5°F.
The standby figure comes from a California test run in a room near 60°F, with the result scaled to a 37°F gap between 102°F water and the air, as if the air were 65°F. In an average Idaho January the gap is about 77°F, 40°F more than the test. Even averaged over the whole year, Idaho is 43.9°F, 21°F colder than the test assumes, so a tub there draws more than its listing for much of the year, not only in winter.
Makers show the effect too. Hot Spring's own example puts one of its tubs at $13.92 a month to heat in 75°F weather and $36.61 in 35°F weather, at the same 11¢ rate. Idaho's January, at 25.1°F, is colder than the cold end of that example. We don't turn that into an Idaho number: no public test shows how each tub's draw changes with the cold, so the costs here stay at the tested standby. In an Idaho winter, treat them as a floor.
For an Idaho winter, compare standby watts within a size: the best hot tubs for cold climates ranks the lowest, and hot tub insulation explains how makers hold the heat.
How much does an efficient hot tub save in Idaho?
About $89 a year for a 6- to 7-seater. The Nordic Hot Tubs Crown draws 131 W on standby against the 209 W median, $12 a month against $20 at Idaho's rate.
The 6- to 7-seaters we track run from 131 W to 287 W, which in Idaho is $177 a year apart, less than the $249 it would be at the US average. Every tub with a filing is ranked on the most energy-efficient hot tubs.
| AventineCaldera Spas · 2 to 3 seats | $10 | $51/yr |
|---|---|---|
| AptosHot Spring · 4 to 5 seats | $11 | $73/yr |
| CrownNordic Hot Tubs · 6 to 7 seats | $12 | $89/yr |
| J509Jacuzzi · 8 or more seats | $14 | $107/yr |
What else changes a hot tub's bill in Idaho?
Use. The figures assume nobody gets in. A soak runs the jet pumps and opens the cover, and the heater has to replace the lost heat; in an Idaho winter more of it escapes while the cover is off.
Temperature. The heater holds the gap between the water and the air. Each degree you take off the set point narrows that gap around the clock, which counts most in an Idaho winter.
Cover. The test runs with the maker's own cover in place. A cover left open, or one that no longer seals, loses heat the test never measured.
Refills. Heating the median six-seater's 392 gallons from 55°F hose water to 102°F takes at least 45 kWh, about $6 at Idaho's rate. Winter tap water in Idaho is colder than that, so it takes more.
How much does a swim spa cost to run in Idaho?
About $41 a month, or $489 a year, for the median swim spa at 12.96¢ per kWh. The median of the 44 swim spas with a California filing draws 431 W on standby. That is about 2.1 times the median 6- to 7-seat hot tub. Costs by model are on swim spa cost.
Common questions
How much does a hot tub add to the electric bill in Idaho?
About $20 a month for a typical 6- to 7-seat tub kept hot at Idaho's average rate of 12.96¢ per kWh, for 153 kWh of measured standby. Across the 317 tubs with a California filing, standby costs $10 to $33 a month there. Soaking, refills and the cold add to it.
Is it more expensive to run a hot tub in Idaho than in other states?
No. Idaho's rate is the 3rd-lowest of the 51, so the same tub costs 29% less to keep hot than at the US average: $20 a month against $28 for the median 6- to 7-seater.
Does a hot tub cost more to run in winter in Idaho?
Yes. The standby figure is scaled to a 37°F gap between 102°F water and the air. Idaho's January averages 25.1°F, a gap of about 77°F, so the heater runs longer than the figure assumes. How much longer depends on the tub's insulation and cover.
Sources
6
- EIA Electric Power Monthly, Table 5.6.BIdaho 12.96¢ and US 18.19¢ per kWh, residential, January to July 2026 (preliminary)
- California Energy Commission appliance efficiency database (portable electric spas)Measured standby power for 317 hot tubs and 44 swim spas
- US Department of Energy, proposed test procedure for portable electric spas, 87 FR 63356Quotes the CEC test room at 60°F (3°F tolerance) and ANSI/APSP/ICC-14's 37°F normalized gap for 102°F water
- NOAA NCEI Climate at a Glance: Idaho statewide, January average temperature25.1°F averaged over 1991–2020; coldest January 2017 at 18.5°F
- NOAA NCEI Climate at a Glance: Idaho statewide, annual average temperature43.9°F averaged over 1991–2020
- Hot Spring: How much will my electric bill increase with a new hot tub?One tub at 11¢ per kWh: $13.92 a month to heat in 75°F weather (Miami), $36.61 in 35°F weather (International Falls, Minnesota)