| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 0.6° | -6.6° | 36.7mm | 8.7 | 15 |
| February | 2.8° | -5.3° | 39.6mm | 7.8 | 18 |
| March | 9° | 0.1° | 54.3mm | 10.2 | 42 |
| April | 15.7° | 5.4° | 88.3mm | 11.9 | 62 |
| May | 21.8° | 11.3° | 104.8mm | 12.6 | 75 |
| June | 27.3° | 17.1° | 99.8mm | 11.4 | 76 |
| July | 29.4° | 20° | 98.6mm | 9.9 | 71 |
| August | 28.3° | 19.3° | 98.4mm | 9.7 | 75 |
| September | 25° | 15.3° | 65.9mm | 8.8 | 82 |
| October | 17.6° | 8.4° | 89.9mm | 11.4 | 70 |
| November | 10.1° | 2° | 50.8mm | 8.8 | 51 |
| December | 3.4° | -3.6° | 49.2mm | 9.4 | 20 |
January in Chicago Lawn averages a daily high of 0.6°C with nights around -6.6°C. Expect roughly 8.7 wet days totalling 36.7mm. A hard month to visit for comfort alone.
February in Chicago Lawn averages a daily high of 2.8°C with nights around -5.3°C. Expect roughly 7.8 wet days totalling 39.6mm. A hard month to visit for comfort alone.
March in Chicago Lawn averages a daily high of 9°C with nights around 0.1°C. Expect roughly 10.2 wet days totalling 54.3mm. Demanding conditions — pack for it and plan indoor options.
April in Chicago Lawn averages a daily high of 15.7°C with nights around 5.4°C. Expect roughly 11.9 wet days totalling 88.3mm. Generally workable, with some weather to plan around.
May in Chicago Lawn averages a daily high of 21.8°C with nights around 11.3°C. Expect roughly 12.6 wet days totalling 104.8mm. Comfortable conditions for being outdoors all day.
June in Chicago Lawn averages a daily high of 27.3°C with nights around 17.1°C. Expect roughly 11.4 wet days totalling 99.8mm. Comfortable conditions for being outdoors all day.
July in Chicago Lawn averages a daily high of 29.4°C with nights around 20°C. Expect roughly 9.9 wet days totalling 98.6mm. Generally workable, with some weather to plan around.
August in Chicago Lawn averages a daily high of 28.3°C with nights around 19.3°C. Expect roughly 9.7 wet days totalling 98.4mm. Comfortable conditions for being outdoors all day.
September in Chicago Lawn averages a daily high of 25°C with nights around 15.3°C. Expect roughly 8.8 wet days totalling 65.9mm. Comfortable conditions for being outdoors all day.
October in Chicago Lawn averages a daily high of 17.6°C with nights around 8.4°C. Expect roughly 11.4 wet days totalling 89.9mm. Generally workable, with some weather to plan around.
November in Chicago Lawn averages a daily high of 10.1°C with nights around 2°C. Expect roughly 8.8 wet days totalling 50.8mm. Demanding conditions — pack for it and plan indoor options.
December in Chicago Lawn averages a daily high of 3.4°C with nights around -3.6°C. Expect roughly 9.4 wet days totalling 49.2mm. A hard month to visit for comfort alone.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Chicago Lawn peaks at 82.
Based on 30 years of records, May–June scores highest for comfort in Chicago Lawn, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29.4°C.
May is the wettest, averaging 104.8mm of rain across roughly 12.6 wet days.
January is the coolest month, with average daily highs around 0.6°C.