Phoenix (AZ) Temperature by Month

Phoenix in Arizona, United States of America sees significant seasonal temperature differences, with daytime highs between 19°C (66°F) in December and 41°C (106°F) in July, averaging 31°C (88°F) annually. Explore the full monthly breakdown below.

With significant temperature fluctuations, Phoenix enjoys distinct seasons year-round. Nighttime lows range from 28°C (82°F) in July to 6°C (43°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Phoenix by month:

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. July, the warmest month, averages 378 hours of sunshine.

The chart below shows the average temperature throughout the year:

Phoenix's average annual maximum temperature is 31°C (88°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.

Seoul, South Korea averages 18°C (64°F) a year, with four clear seasons, cold winters, and hot humid summers.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Phoenix, December is the coolest month, with average highs of 19°C (66°F) and humidity around 51%, considered moderate. In July, the warmest month, temperatures average 41°C (106°F) with 31% humidity, conditions that feel low. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Phoenix's weather, including monthly rainfall, sunshine hours, and humidity, visit our Phoenix climate page.