The biggest temperature swing occurs between October and November, as typical highs shift from 16.2°C / 61.2°F to 8.7°C / 47.7°F (about 7.5°C / 13.4°F).
| Month | Low Temperature | High Temperature | Category |
|---|---|---|---|
| January | -7.5°C | -0.7°C | COLD |
| February | -6.8°C | 1.1°C | COLD |
| March | -1.4°C | 6.5°C | COLD |
| April | 4.4°C | 12.6°C | COOL |
| May | 10.8°C | 18.9°C | MILD |
| June | 17.1°C | 25°C | WARM |
| July | 20°C | 27.4°C | WARM |
| August | 19.6°C | 26.6°C | WARM |
| September | 15.9°C | 23.1°C | WARM |
| October | 9.3°C | 16.2°C | MILD |
| November | 2.3°C | 8.7°C | COOL |
| December | -3.5°C | 2.6°C | COLD |
July has the warmest typical feels-like highs (29.5°C / 85.1°F), while January is coolest (-5.7°C / 21.7°F).
| Month | Low Feels Like | High Feels Like | Category |
|---|---|---|---|
| January | -13.2°C | -5.7°C | COLD |
| February | -12.3°C | -3.8°C | COLD |
| March | -6.4°C | 2.4°C | COLD |
| April | 0.1°C | 9.8°C | COOL |
| May | 8.1°C | 18°C | MILD |
| June | 16.7°C | 26.1°C | WARM |
| July | 20.8°C | 29.5°C | WARM |
| August | 20.4°C | 28.4°C | WARM |
| September | 14.8°C | 22.9°C | WARM |
| October | 5.9°C | 13.6°C | COOL |
| November | -2.4°C | 4.7°C | COLD |
| December | -8.7°C | -2.1°C | COLD |
May is wettest at 117.1 mm / 4.61 inches, while February is driest at 56.7 mm / 2.23 inches.
| Month | Baseline | Rainfall | Category |
|---|---|---|---|
| January | 32.5 mm | 63 mm | MODERATE |
| February | 32.5 mm | 56.7 mm | LIGHT |
| March | 32.5 mm | 70.7 mm | MODERATE |
| April | 32.5 mm | 104.8 mm | MODERATE |
| May | 32.5 mm | 117.1 mm | MODERATE |
| June | 32.5 mm | 106 mm | MODERATE |
| July | 32.5 mm | 104.1 mm | MODERATE |
| August | 32.5 mm | 102.6 mm | MODERATE |
| September | 32.5 mm | 77.2 mm | MODERATE |
| October | 32.5 mm | 91.4 mm | MODERATE |
| November | 32.5 mm | 65.8 mm | MODERATE |
| December | 32.5 mm | 61.1 mm | MODERATE |
June has the strongest peak UV (around index 7.8).
| Month | Baseline | UV Index | Category |
|---|---|---|---|
| January | 0 | 3 | MODERATE |
| February | 0 | 4.4 | MODERATE |
| March | 0 | 5.7 | MODERATE |
| April | 0 | 7 | HIGH |
| May | 0 | 7.5 | HIGH |
| June | 0 | 7.8 | HIGH |
| July | 0 | 7.7 | HIGH |
| August | 0 | 7.3 | HIGH |
| September | 0 | 6.4 | HIGH |
| October | 0 | 5.1 | MODERATE |
| November | 0 | 3.5 | MODERATE |
| December | 0 | 2.4 | LOW-MOD |
Daylight ranges from 9.2h in December to 15.2h in June.
| Month | Baseline | Daylight Hours | Category |
|---|---|---|---|
| January | 0h | 9.5h | SHORT |
| February | 0h | 10.6h | BALANCED |
| March | 0h | 12h | BALANCED |
| April | 0h | 13.4h | LONG |
| May | 0h | 14.6h | LONG |
| June | 0h | 15.2h | LONG |
| July | 0h | 14.9h | LONG |
| August | 0h | 13.8h | LONG |
| September | 0h | 12.5h | BALANCED |
| October | 0h | 11.1h | BALANCED |
| November | 0h | 9.8h | SHORT |
| December | 0h | 9.2h | SHORT |
January is most humid (75%), while October is driest (69.8%).
| Month | Baseline | Humidity (avg) | Category |
|---|---|---|---|
| January | 67.9% | 75% | MUGGY |
| February | 67.9% | 73.6% | HUMID |
| March | 67.9% | 73.1% | HUMID |
| April | 67.9% | 71.4% | HUMID |
| May | 67.9% | 73.1% | HUMID |
| June | 67.9% | 71.9% | HUMID |
| July | 67.9% | 70.9% | HUMID |
| August | 67.9% | 72.3% | HUMID |
| September | 67.9% | 70.5% | HUMID |
| October | 67.9% | 69.8% | HUMID |
| November | 67.9% | 71.1% | HUMID |
| December | 67.9% | 74.8% | HUMID |
November has the strongest typical average wind (17.7 km/h / 11.0 mph), while August is calmest (12.3 km/h / 7.6 mph).
| Month | Baseline | Wind (avg) | Category |
|---|---|---|---|
| January | 10.1 km/h | 17.4 km/h | CALM |
| February | 10.1 km/h | 17 km/h | CALM |
| March | 10.1 km/h | 16.7 km/h | CALM |
| April | 10.1 km/h | 17.3 km/h | CALM |
| May | 10.1 km/h | 15.7 km/h | CALM |
| June | 10.1 km/h | 13.9 km/h | CALM |
| July | 10.1 km/h | 12.6 km/h | CALM |
| August | 10.1 km/h | 12.3 km/h | CALM |
| September | 10.1 km/h | 14.2 km/h | CALM |
| October | 10.1 km/h | 16.8 km/h | CALM |
| November | 10.1 km/h | 17.7 km/h | CALM |
| December | 10.1 km/h | 16.9 km/h | CALM |
April is windiest by P95 gust signal (64.1 km/h / 39.8 mph).
| Month | Baseline | Wind (gusts) | Category |
|---|---|---|---|
| January | 0 km/h | 56.5 km/h | VERY WINDY |
| February | 0 km/h | 60.1 km/h | VERY WINDY |
| March | 0 km/h | 60.8 km/h | VERY WINDY |
| April | 0 km/h | 64.1 km/h | VERY WINDY |
| May | 0 km/h | 58.7 km/h | VERY WINDY |
| June | 0 km/h | 52.6 km/h | VERY WINDY |
| July | 0 km/h | 48.2 km/h | WINDY |
| August | 0 km/h | 47.2 km/h | WINDY |
| September | 0 km/h | 51.8 km/h | VERY WINDY |
| October | 0 km/h | 58.3 km/h | VERY WINDY |
| November | 0 km/h | 59 km/h | VERY WINDY |
| December | 0 km/h | 58 km/h | VERY WINDY |
May has the most rain days (~14.9), while February has the fewest (~10). Rain days count the average number of days in a month with measurable rain (about 0.1 mm or more).
| Month | Baseline | Rain Days | Category |
|---|---|---|---|
| January | 8.1 days | 12 days | FREQUENT |
| February | 8.1 days | 10 days | FREQUENT |
| March | 8.1 days | 12.3 days | FREQUENT |
| April | 8.1 days | 14.6 days | FREQUENT |
| May | 8.1 days | 14.9 days | FREQUENT |
| June | 8.1 days | 14.3 days | FREQUENT |
| July | 8.1 days | 14.2 days | FREQUENT |
| August | 8.1 days | 14.2 days | FREQUENT |
| September | 8.1 days | 10.7 days | FREQUENT |
| October | 8.1 days | 12.1 days | FREQUENT |
| November | 8.1 days | 10.7 days | FREQUENT |
| December | 8.1 days | 11.4 days | FREQUENT |
April has the most heavy rain/washout risk days (~7). Heavy rain days are the average number of days likely to bring stronger downpours that can disrupt outdoor plans.
| Month | Baseline | Heavy Rain Days | Category |
|---|---|---|---|
| January | 0 days | 4 days | FREQUENT |
| February | 0 days | 4 days | FREQUENT |
| March | 0 days | 5 days | FREQUENT |
| April | 0 days | 7 days | PERSISTENT |
| May | 0 days | 7 days | PERSISTENT |
| June | 0 days | 6 days | PERSISTENT |
| July | 0 days | 6 days | PERSISTENT |
| August | 0 days | 6 days | PERSISTENT |
| September | 0 days | 4 days | FREQUENT |
| October | 0 days | 5 days | FREQUENT |
| November | 0 days | 4 days | FREQUENT |
| December | 0 days | 4 days | FREQUENT |
July has the highest heat-risk day count (~3 days). Heat days are the average number of days that exceed our location-specific heat-risk threshold.
| Month | Baseline | Heat Days | Category |
|---|---|---|---|
| January | 0 days | 0 days | LOW |
| February | 0 days | 0 days | LOW |
| March | 0 days | 0 days | LOW |
| April | 0 days | 0 days | LOW |
| May | 0 days | 0 days | LOW |
| June | 0 days | 1 days | LOW |
| July | 0 days | 3 days | ELEVATED |
| August | 0 days | 2 days | ELEVATED |
| September | 0 days | 0 days | LOW |
| October | 0 days | 0 days | LOW |
| November | 0 days | 0 days | LOW |
| December | 0 days | 0 days | LOW |
Daylight varies from 9.2 hours in December (winter) to 15.2 hours in June (summer), which is a difference of 6 hours.
Northern Hemisphere seasons shape the weather patterns throughout the year. Here's what to expect in each season:
A month-by-month ranking of key weather risks and comforts for this destination, based on historical climate data.
| Ranking Goal | #1 | #2 | #3 | #4 |
|---|---|---|---|---|
| Lowest rain risk | Jan 4 risk days | Feb 4 risk days | Sep 4 risk days | Nov 4 risk days |
| Lowest heatwave risk | Jan 0 risk days | Feb 0 risk days | Mar 0 risk days | Apr 0 risk days |
| Lowest cold risk | Jul 0 risk days | Aug 0 risk days | Jun 1 risk days | Sep 2 risk days |
| Lowest wind disruption risk | Aug 47 km/h | Jul 48 km/h | Sep 52 km/h | Jun 53 km/h |
| Most comfortable evenings | Sep 78 / 100 | Jun 77 / 100 | Aug 71 / 100 | Jul 69 / 100 |
| Best outdoor reliability | Sep 95 / 100 | Jan 89 / 100 | Dec 87 / 100 | Nov 86 / 100 |
Click any month for detailed weather information and packing advice.
Get personalized month rankings based on weather comfort, outdoor activity suitability, and seasonal conditions.
Travel planning FAQ
Quick answers to the weather questions you ask the most.
The best months to visit Chicago depend on your preferences. For warm weather, July is typically the warmest month. For dry conditions, February, December, January tend to have the least rainfall. Consider your priorities, and whether you prefer warmer temperatures, drier weather, or longer daylight hours.
July is typically the warmest month in Chicago, with average high temperatures reaching around 27°C (81°F). This is peak summer weather, ideal for outdoor activities and sightseeing.
January is usually the coldest month, with average low temperatures dropping to around -8°C (18°F). Pack warm layers if visiting during this time, especially for evening activities.
May typically sees the most rainfall in Chicago, averaging around 117mm (4.6 inches). It's wise to pack waterproof layers and have some indoor backup plans if you're visiting during this month.
February is typically the driest month, with average rainfall of just 57mm (2.2 inches). This makes it an excellent time for outdoor exploration and activities with minimal risk of rain disruption.
Temperatures in Chicago range from average lows of 7°C (44°F) to highs of 14°C (57°F). This variation means you'll want to pack differently depending on when you visit, as layers are key for adapting to the seasonal changes.
Yes, sun protection is important in Chicago. UV levels can reach 8 during peak months, which is considered high. Pack sunscreen (SPF 30+), sunglasses, and a hat, especially if you'll be outdoors for extended periods.