Arizona Time Zone Map
Arizona uses Mountain Standard Time (MST, UTC-7) all year and is the only contiguous US state that does not observe Daylight Saving Time. The Navajo Nation in northeast Arizona is the sole exception.
Simplified visual guide. Arizona's exemption from DST is established under federal law (Uniform Time Act, 1966). The Navajo Nation exercises its sovereign right to observe DST.
What Time Zone Is Arizona In?
Arizona uses Mountain Standard Time (MST, UTC-7) all year. Unlike every other state in the contiguous United States, Arizona does not change its clocks for Daylight Saving Time. Phoenix, Tucson, Flagstaff, Scottsdale, Mesa, Tempe, and all other Arizona cities stay on MST regardless of the season.
The one exception is the Navajo Nation, a sovereign tribal nation whose lands span parts of Arizona, Utah, and New Mexico. The Navajo Nation independently chose to observe Daylight Saving Time. During summer (March to November), Navajo Nation areas in Arizona run on MDT (UTC-6) while the surrounding state uses MST (UTC-7). This means a one-hour difference between a Navajo Nation community like Kayenta or Window Rock and nearby Arizona cities like Flagstaff during DST months.
Within the Navajo Nation, the Hopi Reservation (which is completely surrounded by Navajo land) does not observe DST — matching the rest of Arizona at MST year-round. This creates an unusual situation where driving through the region you may pass through three time zones in a single trip.
Arizona Cities and Regions by Time Zone
| Time Zone | Region | Major Cities | UTC Offset |
|---|---|---|---|
| Mountain Standard Time (MST) | All of Arizona except Navajo Nation | Phoenix, Tucson, Flagstaff, Scottsdale, Mesa, Tempe, Chandler, Gilbert | MST UTC-7 (year-round, no DST) |
| Mountain Time (MST/MDT) | Navajo Nation (northeast Arizona) | Window Rock, Kayenta, Chinle, Tuba City, Ganado | MST UTC-7 (winter) / MDT UTC-6 (summer) |
Arizona vs Other States: Time Differences by Season
Because Arizona never changes its clocks, the time difference between Arizona and other states shifts depending on the time of year:
| City / State | Winter (no DST) | Summer (during DST) |
|---|---|---|
| Los Angeles (CA) | AZ 1 hr ahead (PST UTC-8) | Same time (PDT UTC-7) |
| Denver (CO) | Same time (MST UTC-7) | AZ 1 hr behind (MDT UTC-6) |
| Dallas (TX) | AZ 1 hr behind (CST UTC-6) | AZ 2 hrs behind (CDT UTC-5) |
| New York (NY) | AZ 2 hrs behind (EST UTC-5) | AZ 3 hrs behind (EDT UTC-4) |
* AZ = Arizona (MST, UTC-7 year-round). DST period is approximately March to November.
Why Arizona Does Not Observe Daylight Saving Time
Arizona opted out of Daylight Saving Time in 1968, just two years after the federal Uniform Time Act of 1966 established a national DST standard. The Arizona legislature voted to remain on standard time year-round. The primary reason was the state's extreme summer heat.
In summer, Arizona temperatures regularly exceed 110°F (43°C). Extending daylight by one hour in the evening would push the hottest part of the afternoon further into evening hours — making the peak heat last longer during the time most people are outdoors, commuting, or active. The state decided that the energy savings DST was designed to produce did not outweigh this heat burden.
There have been occasional legislative discussions about changing Arizona's DST status, but the state has remained on permanent MST since 1968 — now over 55 years of stable, consistent Mountain Standard Time.
Note: Under the Uniform Time Act, states may exempt themselves from observing DST by passing a state law. Hawaii also exercises this exemption, making Arizona and Hawaii the only two US states that do not observe Daylight Saving Time.
Does Arizona Observe Daylight Saving Time?
No. Arizona does not observe Daylight Saving Time. The state stays on MST (UTC-7) all year. Clocks in Arizona never spring forward in March or fall back in November.
The practical effect is that Arizona shares a clock with different states at different times of year. In winter, Arizona matches Mountain Time states like Colorado and Utah. In summer, when those states move to MDT, Arizona instead matches Pacific Daylight Time states like California and Nevada — all on UTC-7 during summer.
For travelers and remote workers scheduling calls between Arizona and other states, this means the time difference changes twice a year in March and November — not because Arizona changes, but because every other state does.
Frequently Asked Questions — Arizona Time Zone
Is Phoenix on the same time as Los Angeles in summer?
Yes. In summer, Los Angeles is on PDT (UTC-7) and Phoenix is on MST (UTC-7). They share the same clock time from March to November each year.
Is the Navajo Nation time zone the same as Arizona?
In winter, yes — both are MST (UTC-7). In summer, no — the Navajo Nation observes DST and moves to MDT (UTC-6), while the rest of Arizona stays on MST (UTC-7). This makes them 1 hour apart in summer.
What UTC offset is Arizona?
Arizona is UTC-7 (Mountain Standard Time) all year. It never changes to UTC-6 because the state does not observe Daylight Saving Time.
What time zone is Tucson in?
Tucson uses Mountain Standard Time (MST, UTC-7) year-round. Like all of Arizona outside the Navajo Nation, Tucson does not observe daylight saving time.