The very simple reason why Idaho doesn’t do daylight saving time, along with Hawaii, comes down to geography and climate. Unlike most U.S. states, Idaho does observe daylight saving time in part—but the panhandle region that lies north of the 45th parallel aligns more closely with Pacific Time and has minimal daylight variation throughout the year, making daylight saving less necessary there. However, notable exceptions are Hawaii and most of Arizona:
Hawaii does not observe daylight saving time because it is located near the equator, where daylight hours remain relatively constant year-round, so “saving” daylight is unnecessary.
Arizona (except for the Navajo Nation) opts out mainly due to its desert climate; extending daylight hours into the evening in hot months would increase energy consumption for air conditioning, so staying on standard time helps conserve energy.
The Uniform Time Act allows states to opt out of daylight saving time by observing standard time year-round, as Hawaii and Arizona have done. Several other states, including Idaho, have debated or passed legislation to adopt permanent daylight saving time but must await federal approval to change the system fully.
In summary, Idaho aligns with daylight saving time federally but has parts with geographic and daylight conditions similar to Hawaii and Arizona, which do not observe daylight saving due to minimal daylight variation or energy conservation reasons.
So, the simple reason: states like Hawaii don’t do daylight saving because their daylight stays constant, and Arizona avoids it mostly because staying on standard time reduces energy costs in their hot climate. Idaho partially observes it but shares similar geographic reasoning in parts of the state.
SOURCES
[1](https://worldpopulationreview.com/state-rankings/daylight-savings-time-by-state)
[2](https://thehill.com/homenews/nexstar_media_wire/5184764-two-states-didnt-spring-forward/)
[3](https://www.transportation.gov/regulations/daylight-saving-time)
[4](https://economictimes.com/news/international/us/when-daylight-saving-time-2025-fall-back-date-end-states-observe-what-reason-us-states-territories-do-not-follow-how-to-prepare/articleshow/123099184.cms)
[5](https://ddnews.gov.in/en/why-does-trump-want-to-make-us-daylight-saving-time-permanent/)
