Chicago’s weather is famously unpredictable, shaped by its location along Lake Michigan and the Midwest’s continental climate. The city experiences all four seasons distinctly, from snowy winters to hot, humid summers. Below is a month-by-month breakdown of Chicago weather to help you plan travel, events, or daily life.
Chicago Weather by Month
January: Cold and Snowy
January is typically the coldest month in Chicago.
- Average temperature: 18–31°F (-8 to -1°C)
- Conditions: Frequent snow, icy winds, and occasional polar vortex events
- What to expect: Heavy coats, snow boots, and limited outdoor activities
February: Bitter Cold with Occasional Thaws
February remains very cold, though brief warm-ups can occur.
- Average temperature: 22–35°F (-6 to 2°C)
- Conditions: Snowfall continues, windy days are common
- What to expect: Winter still dominates, but daylight slowly increases
March: Transition to Spring
March marks the beginning of seasonal change.
- Average temperature: 32–47°F (0–8°C)
- Conditions: Rain, melting snow, and fluctuating temperatures
- What to expect: Unpredictable weather—winter coats are still needed
April: Cool and Rainy
Spring becomes more noticeable in April.
- Average temperature: 41–59°F (5–15°C)
- Conditions: Rain showers, blooming trees, occasional chilly days
- What to expect: A mix of sunshine and rain; layering is key
May: Mild and Pleasant
May is one of Chicago’s most comfortable months.
- Average temperature: 51–70°F (11–21°C)
- Conditions: Warmer days, moderate rain, low humidity
- What to expect: Great weather for outdoor activities and festivals
June: Warm with Growing Humidity
Summer begins in June.
- Average temperature: 61–80°F (16–27°C)
- Conditions: Sunny days, rising humidity, occasional thunderstorms
- What to expect: Ideal for lakefront activities and sightseeing
July: Hot and Humid
July is usually the hottest month.
- Average temperature: 66–85°F (19–29°C)
- Conditions: High humidity, heat waves, summer storms
- What to expect: Busy tourist season; air conditioning is essential
August: Warm with Late-Summer Storms
August remains hot but begins to cool slightly toward the end.
- Average temperature: 65–84°F (18–29°C)
- Conditions: Humidity, thunderstorms, warm lake temperatures
- What to expect: Great beach weather, especially near Lake Michigan
September: Comfortable and Crisp
Early fall brings some of the best weather of the year.
- Average temperature: 57–76°F (14–24°C)
- Conditions: Lower humidity, sunny days, cool nights
- What to expect: Perfect for walking, festivals, and outdoor dining
October: Cool and Colorful
Autumn fully settles in.
- Average temperature: 46–63°F (8–17°C)
- Conditions: Fall foliage, cooler air, occasional rain
- What to expect: Sweaters and light jackets become necessary
November: Chilly and Gray
Temperatures drop quickly in November.
- Average temperature: 35–49°F (2–9°C)
- Conditions: Cloudy skies, rain turning to snow late in the month
- What to expect: Early signs of winter, shorter days
December: Cold with Holiday Snow
December brings winter back in full force.
- Average temperature: 25–36°F (-4 to 2°C)
- Conditions: Snowfall, icy roads, festive city lights
- What to expect: Cold weather balanced by holiday charm
Chicago Weather by Month Table
| Month | Average High | Average Low | Weather Conditions |
|---|---|---|---|
| January | 31°F (-1°C) | 18°F (-8°C) | Very cold, snowy, windy |
| February | 35°F (2°C) | 22°F (-6°C) | Cold, snow continues |
| March | 47°F (8°C) | 32°F (0°C) | Cool, rain and melting snow |
| April | 59°F (15°C) | 41°F (5°C) | Mild, rainy, early spring |
| May | 70°F (21°C) | 51°F (11°C) | Pleasant, low humidity |
| June | 80°F (27°C) | 61°F (16°C) | Warm, occasional storms |
| July | 85°F (29°C) | 66°F (19°C) | Hot, humid |
| August | 84°F (29°C) | 65°F (18°C) | Warm, humid, storms |
| September | 76°F (24°C) | 57°F (14°C) | Comfortable, dry |
| October | 63°F (17°C) | 46°F (8°C) | Cool, fall colors |
| November | 49°F (9°C) | 35°F (2°C) | Chilly, cloudy |
| December | 36°F (2°C) | 25°F (-4°C) | Cold, snowy |
10 FAQs about Weather in Chicago
- What is the coldest month in Chicago?
January is usually the coldest month, with average temperatures often below freezing and frequent snowfall. - What is the hottest month in Chicago?
July is typically the hottest month, with high temperatures often reaching the mid-80s°F (around 29°C) and high humidity. - Which month has the most snowfall in Chicago?
January usually receives the most snowfall, though February can sometimes rival it depending on the year. - When is the best month to visit Chicago for good weather?
May, June, and September are considered the best months due to mild temperatures and lower humidity. - Does Chicago get a lot of rain?
Chicago has moderate rainfall spread throughout the year, with late spring and summer seeing more frequent thunderstorms. - When does winter usually start in Chicago?
Winter conditions often begin in late November or early December, with snow and freezing temperatures becoming more consistent. - How humid is Chicago in the summer?
Summer months, especially July and August, can be quite humid due to heat and proximity to Lake Michigan. - Is Chicago windy all year?
Yes, Chicago experiences wind throughout the year, but winds feel strongest in winter because of cold temperatures. - Does Lake Michigan affect Chicago’s weather?
Yes, Lake Michigan moderates temperatures, cooling the city in summer and enhancing snowfall in winter. - Can Chicago weather change quickly?
Absolutely. Chicago is known for rapid weather changes, sometimes experiencing multiple seasons in a single week.
Conclusion
Chicago’s weather changes dramatically throughout the year, offering something for everyone—from snowy winters to vibrant summers and crisp autumns. Understanding Chicago weather by month helps residents and visitors prepare for the city’s unique climate and enjoy all it has to offer, no matter the season.