Arizona Climate – July 2026 Update
Top 5 Cities: Phoenix, Tucson, Mesa, Chandler, and Scottsdale
Summary
Arizona experienced its 4th warmest July on record, capping a May to July stretch that ranked as the state's 3rd warmest ever while setting record overnight low temperatures across the region. The sustained warmth coincides with a moderate El Niño forecast to peak at Very Strong in autumn, with monsoon activity expected to bring above-average rainfall into the winter months.
This month in numbers
July 2026 averaged 28.28°C, sitting 1.6°C above the 1961–1990 baseline to rank 4th warmest for the month in 77 years of records. Daytime maximum temperatures averaged 36.06°C (+1.5°C anomaly), the 7th highest on record. Rainfall reached 48.77 mm (+3.0 mm above baseline), ranking as the 29th wettest July as monsoon thunderstorms brought localised downbursts and short-term moisture relief.
What changed
The May to July 2026 period averaged 24.93°C (+2.0°C anomaly), marking the 3rd warmest such 3-month stretch on record for the state. Over the past 12 months, Arizona recorded an average temperature anomaly of +3.04°C, placing it 5th overall out of 232 countries and territories tracked globally. Arizona's sustained heat reflects a striking North American pattern, where seven of the top 10 warmest 12-month regional anomalies globally were US states. Nationally, the contiguous United States experienced its warmest month on record in July 2026.
What’s driving change?
Recent regional heat has been driven by persistent that trapped hot air across the Southwest, combined with that reduced natural evaporative cooling. In urban centres, the effect restricted overnight cooling, driving minimum temperatures to record highs. On a larger scale, ENSO is currently in a moderate El Niño phase in the tropical Pacific, with live tracking available at ENSO. All of Arizona's 2 wildfires this year have happened in the past month. All of Arizona's 1 flood this year has occurred in the past month, tracked on our map at Extreme Weather tracker.
Looking ahead
With NOAA forecasting a 93% probability that El Niño will reach Very Strong intensity between September and November, seasonal outlooks lean toward above-average precipitation across Arizona through the coming autumn and winter.
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
Climate Map – USUnited States
Source: NOAA Climate at a Glance — US states & climate regions (tavg, pcp), plus GPCC (Snow, water-equivalent). Anomalies are vs the 1961–1990 baseline. See methodology.
Typical Climate – Arizona
Köppen BSk · AridArizona has a arid climate (Köppen BSk: Cold steppe), with both a warm/cold cycle and a wet/dry cycle through the year. July is typically the warmest month, averaging 28.1°C, while January is the coldest at 5.9°C. Annual precipitation averages around 279mm, concentrated mostly in the wet season.
Monthly climate normals (2016–2025) - bar colour and height show average temperature, the shaded area shows average monthly rain, with snow (water-equivalent) shown separately.
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Long-Term Trends
Combined Timeline – Arizona
Precipitation, Sunshine, Frost and Snow are converted to standard deviations from their own average so they can share an axis with Temperature.
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Heatwave Days – Arizona
Warm Spell Duration Index (WSDI) - days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived). Refreshed roughly 1-2x/year, ~7-8 months behind present.
Year-on-Year Trends
The 4byo Climate Helix – Arizona
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Monthly Temperature – Arizona
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Records – Arizona
NOAA National Centers for Environmental Information (frost: World Bank CCKP; snow: GPCC (DWD)) - Anomalies vs 1901-2000 mean
Shifting Seasons
Warm/cold + wet/dryKöppen BSk · AridArizona has both a clear warm/cold cycle (±11.0°C) and a wet/dry cycle (7× wet:dry ratio). Both sides of the annual rhythm are shown below.
Monthly precipitation climatology. A “wet month” exceeds the baseline monthly mean (dashed gold line). Biggest month-to-month shift: Aug (-7 mm, -13%).
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Climate Systems
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Emissions & Energy
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Data Sources
Data Sources for Arizona
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
Statewide monthly temperature and precipitation (nClimDiv).
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in Arizona changing?
Arizona is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
What is the climate like in Arizona?
Arizona has a arid climate (Köppen BSk: Cold steppe), with both a warm/cold cycle and a wet/dry cycle through the year. July is typically the warmest month, averaging 28.1°C, while January is the coldest at 5.9°C. Annual precipitation averages around 279mm, concentrated mostly in the wet season.
Where does the climate data for Arizona come from?
Climate data for Arizona comes from NOAA Climate at a Glance (temperature and precipitation), refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the Arizona climate data cover?
The Arizona climate profile covers Phoenix, Tucson, Mesa, Chandler and surrounding areas. Arizona climate data from NOAA Climate at a Glance
How often is the Arizona climate update refreshed?
The Arizona climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the Arizona climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the Arizona climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.