Phoenix is 17.6°C (31.7°F) warmer by day, Phoenix has 8.2°C (14.8°F) warmer nights, Chicago gets 673 mm (26.5 in) more rain a year.
Chicago is at its warmest in August and coolest in January, while Phoenix peaks in July and bottoms out in January. Month for month, Phoenix is the warmer of the two in 12 of 12 months.
Chicago is the wetter of the two, collecting 967 mm (38.1 in) of rain a year against 294 mm (11.6 in) in Phoenix. The most comfortable time to visit is July, August and September in Chicago and April, October and November in Phoenix.
| Chicago | Metric | Phoenix |
|---|---|---|
| 🌡️ Temperature | ||
| 54°F | 🌡️Average daytime high | 85.6°F |
| 43.9°F | 🌙Average nighttime low | 58.6°F |
| August | 🔥Hottest month | July |
| January | ❄️Coldest month | January |
| 🌧️ Rain | ||
| 38.1 in | 🌧️Annual rainfall | 11.6 in |
| May | ☔Wettest month | August |
| January | 🏜️Driest month | June |
| 💨 Climate | ||
| 81% | 💧Average humidity | 35% |
| 4.4 m/s | 💨Average wind speed | 2 m/s |
Overnight, Chicago typically falls to around 6.6°C (43.9°F) while Phoenix settles near 14.8°C (58.6°F).
Chicago is hottest in August and coldest in January, whereas Phoenix peaks in July and is coolest in January.
Chicago sees the most rain in May and the least in January; Phoenix is wettest in August and driest in June.
Chicago feels the more humid of the two, averaging 81% relative humidity against 35%.
For Phoenix, the pick of the year is April, October and November.
Month by month, here is the coldest night, the average day and the hottest afternoon each city can expect. Switch Compare to read rainfall, humidity, wind or solar instead, and Period to move between the long-term 45-year average and any single year — the shading is a quick warm-to-cool guide.
| Month | Chicago | Phoenix | ||||
|---|---|---|---|---|---|---|
| Min | Avg | Max | Min | Avg | Max | |
| January | 22.1 | 26.6❄️ | 31.1 | 41 | 53.6❄️ | 66.2 |
| February | 23.7 | 28.4 | 33.1 | 43.2 | 56.1 | 69.3 |
| March | 30.9 | 36 | 41 | 47.3 | 61.5 | 75.6 |
| April | 38.5 | 44.1 | 49.6 | 53.4 | 68.7 | 84 |
| May | 47.1 | 52.9 | 58.6 | 62.4 | 77.9 | 93.4 |
| June | 57.9 | 63.5 | 69.1 | 72.7 | 88.3 | 104.2 |
| July | 66.2 | 71.1 | 75.9 | 79.7 | 92.3🔥 | 105.1 |
| August | 66.6 | 71.4🔥 | 76.1 | 79 | 91 | 103.1 |
| September | 60.1 | 65.3 | 70.5 | 72.7 | 85.8 | 98.8 |
| October | 48.7 | 54 | 59.2 | 60.8 | 74.3 | 87.8 |
| November | 37.4 | 42.1 | 46.6 | 49.5 | 62.4 | 75.4 |
| December | 27.7 | 31.6 | 35.8 | 41.5 | 53.8 | 65.8 |
| Annual Avg | 43.9 | 48.9 | 54 | 58.6 | 72.1 | 85.6 |
Min / mean / max temperature (°F). 🔥 marks each city's hottest month, ❄️ its coldest; shading runs cool blue to warm red.
The same figures plotted out, so the shape of a typical year is easier to see than in a grid. Where the two lines run close together Chicago and Phoenix feel alike; where they separate, they are genuinely different places to be.
Hover or tap any point to read the exact figures. Chicago Phoenix
See how Chicago and Phoenix stack up against other cities. Swipe for more.
Choose which city to keep, then search for any other city in our database — we'll build the comparison for you.
Quick answers to the questions people ask most when comparing Chicago and Phoenix — each drawn straight from the climate figures above.
Phoenix is the warmer of the two. It averages daytime highs of 29.8°C (85.6°F) against 12.2°C (54°F) in Chicago — roughly 17.6°C (31.7°F) warmer by day. Nights are milder in Phoenix, with average lows of 14.8°C (58.6°F) versus 6.6°C (43.9°F).
Chicago is hottest in August, averaging highs of about 24.5°C (76.1°F), while Phoenix peaks in July at around 40.6°C (105.1°F). That makes Phoenix the hotter of the two at the height of summer.
Chicago gets colder. In its coldest month (January) overnight lows average about -5.5°C (22.2°F), compared with 5°C (41.1°F) at the low point of the year in Phoenix.
Chicago is the wetter city, collecting about 967 mm (38.1 in) of rain a year versus 294 mm (11.6 in) in Phoenix. Chicago is wettest in May and driest in January; Phoenix is wettest in August and driest in June.
Chicago is the more humid of the two, averaging 81% relative humidity over the year against 35% in Phoenix.
The most comfortable months in Chicago are July, August and September, when average temperatures are at their mildest.
Phoenix is at its most pleasant around April, October and November, based on the mildest average temperatures of the year.
Phoenix is the warmer city in all 12 months of the year. The gap is widest in February, about 15.4°C (27.7°F), and narrowest in August, about 10.9°C (19.6°F).
Chicago has the bigger seasonal swing, about 24.9°C (44.8°F) between its coldest and hottest months versus 21.5°C (38.7°F) in Phoenix — so Phoenix has the steadier, more even climate.
On climate alone, Phoenix comes out ahead — it offers warmer days, less rain and lower humidity than Chicago. Chicago is the better fit only if you'd actually prefer cooler weather, more rainfall and a more humid climate.
Every figure on this page is calculated from NASA POWER satellite climate data spanning 1981–2025 (45 years). The averages describe the long-term climate of Chicago and Phoenix, not a single year's weather or a short-range forecast.
