Chicago Weather
A month-by-month look at temperature, rainfall and what to pack in Chicago. The annual average is 14°C high / 5°C low — hottest in July (peak summer) (29°C) and coldest in January (deep winter) (-10°C).
Chicago Weather at a Glance
As of 2026A quick summary of Chicago's year-round climate and the best time to visit.
- Annual average
- 14° / 5°
- Best time to visit
- September (best month), May (excellent), June (early summer)
- Hottest month
- July (peak summer) (29°C)
- Coldest month
- January (deep winter) (-10°C)
- Wettest month
- May (excellent) (105mm)
- Driest month
- February (winter peak) (45mm)
As of 2026, Chicago's weather averages 14°C high / 5°C low across the year, and the best time to visit for stable temperatures, rainfall and crowds is September (best month), May (excellent), June (early summer). The hottest month is July (peak summer) (29°C), the coldest is January (deep winter) (-10°C), and the wettest is May (excellent) (105mm).
Best Time to Visit Chicago
**September is the sleeper-best Chicago month.** Warm + sunny (24°C) but smaller crowds + hotel rates drop 30% from August. **Chicago Jazz Festival** (Labor Day weekend, free) is the city's premier free jazz event. Cubs season ending; baseball energy high. Wrigleyville pubs lively.
**May is the sleeper-best Chicago month.** Weather warming (20°C average) but not yet peak summer crowds. Hotel rates still moderate. Outdoor festivals + patios + lakefront all open. Architecture Cruise + Wrigley + Mag Mile all comfortable. Memorial Day weekend marks the start of summer-season festivities.
**June is when summer arrives** — peak outdoor festivals season begins. **Chicago Blues Festival** (Grant Park, free, 1st weekend) is the largest free blues festival in the world. **Chicago Pride Parade** (last Sunday) draws 1 million+. Hotel rates rising toward summer peak.
Chicago Weather Month by Month
Tap any month for a detailed guide with what to wear, sunrise/sunset and air quality.
| Month | High/Low | Rain | Rainy days | Crowds | |
|---|---|---|---|---|---|
| January (deep winter) | -1° / -10° | 50mm | 10 | Quiet | Details → |
| February (winter peak) | 1° / -9° | 45mm | 9 | Quiet | Details → |
| March (winter ending) | 7° / -3° | 70mm | 11 | Quiet | Details → |
| April (spring) | 14° / 4° | 95mm | 12 | Moderate | Details → |
| May (excellent) | 20° / 10° | 105mm | 12 | Moderate | Details → |
| June (early summer) | 26° / 16° | 100mm | 11 | Busy | Details → |
| July (peak summer) | 29° / 19° | 100mm | 10 | Very busy | Details → |
| August (Lollapalooza) | 28° / 18° | 100mm | 9 | Very busy | Details → |
| September (best month) | 24° / 13° | 95mm | 9 | Busy | Details → |
| October (autumn) | 16° / 7° | 80mm | 10 | Moderate | Details → |
| November (early winter) | 7° / 0° | 70mm | 10 | Quiet | Details → |
| December (holiday season) | 1° / -5° | 60mm | 9 | Busy | Details → |
What to Wear in Chicago by Season
Spring — high 14°C, low 4°C. Light jacket + sweater + sunglasses. Umbrella for spring showers. Cubs season begins.
Peak summer — high 29°C, low 19°C. T-shirt + shorts daytime. Light layers evenings (still 19°C). Sunscreen + sunglasses + swimsuit.
Autumn — high 16°C, low 7°C. Light jacket + sweater + umbrella. Cubs postseason if Cubs make playoffs.
Late winter — same as January. Wind chill still -20°C possible. Layered approach for outdoor 1-hour stints + indoor 2-hour escapes.
Chicago Weather FAQ
What is the best time to visit Chicago? +
For weather, September (best month), May (excellent), June (early summer) are the most comfortable months. Highs sit around 24°C with relatively stable rainfall and crowds.
What are the hottest and coldest months in Chicago? +
The hottest month is July (peak summer) with an average high of 29°C, and the coldest is January (deep winter) with an average low of -10°C. The annual average is 14°C high / 5°C low.
When does it rain most in Chicago? +
The wettest month is May (excellent) (105mm over about 12 rainy days) and the driest is February (winter peak) (45mm). Total annual rainfall is roughly 970mm.
What should I pack for Chicago? +
Spring (Mar–May) averages 14/4°C — Spring — high 14°C, low 4°C. Light jacket + sweater + sunglasses. Umbrella for spring showers. Cubs season begins. Summer (Jun–Aug) averages 28/18°C — Peak summer — high 29°C, low 19°C. T-shirt + shorts daytime. Light layers evenings (still 19°C). Sunscreen + sunglasses + swimsuit. Autumn (Sep–Nov) averages 16/7°C — Autumn — high 16°C, low 7°C. Light jacket + sweater + umbrella. Cubs postseason if Cubs make playoffs. Winter (Dec–Feb) averages 0/-8°C — Late winter — same as January. Wind chill still -20°C possible. Layered approach for outdoor 1-hour stints + indoor 2-hour escapes.
What is the weather in Chicago this month (June (early summer))? +
June (early summer) averages 26°C high / 16°C low with 100mm rainfall over about 11 rainy days. Crowds are busy and prices are high.
Keep Planning Your Chicago Trip
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.