| Day of Month | High | Low | Average | HDD | CDD | Precipitation | Snowfall |
| 1 | 40 | 25 | 32 | 33 | 0 | 0.08 | 0.2 |
| 2 | 41 | 25 | 33 | 32 | 0 | 0.07 | 0.3 |
| 3 | 41 | 25 | 33 | 32 | 0 | 0.08 | 0.2 |
| 4 | 42 | 26 | 34 | 31 | 0 | 0.08 | 0.3 |
| 5 | 42 | 26 | 34 | 31 | 0 | 0.08 | 0.2 |
| 6 | 43 | 26 | 34 | 31 | 0 | 0.08 | 0.2 |
| 7 | 43 | 26 | 35 | 30 | 0 | 0.08 | 0.3 |
| 8 | 43 | 27 | 35 | 30 | 0 | 0.07 | 0.2 |
| 9 | 44 | 27 | 35 | 30 | 0 | 0.08 | 0.3 |
| 10 | 44 | 27 | 36 | 29 | 0 | 0.07 | 0.2 |
| 11 | 45 | 28 | 36 | 29 | 0 | 0.08 | 0.2 |
| 12 | 45 | 28 | 36 | 29 | 0 | 0.07 | 0.2 |
| 13 | 45 | 28 | 37 | 28 | 0 | 0.07 | 0.2 |
| 14 | 46 | 29 | 37 | 28 | 0 | 0.07 | 0.2 |
| 15 | 46 | 29 | 38 | 27 | 0 | 0.08 | 0.2 |
| 16 | 47 | 29 | 38 | 27 | 0 | 0.08 | 0.2 |
| 17 | 47 | 30 | 38 | 27 | 0 | 0.08 | 0.2 |
| 18 | 47 | 30 | 39 | 26 | 0 | 0.08 | 0.1 |
| 19 | 48 | 30 | 39 | 26 | 0 | 0.08 | 0.2 |
| 20 | 48 | 31 | 39 | 26 | 0 | 0.08 | 0.1 |
| 21 | 49 | 31 | 40 | 25 | 0 | 0.09 | 0.2 |
| 22 | 49 | 31 | 40 | 25 | 0 | 0.09 | 0.1 |
| 23 | 50 | 31 | 40 | 25 | 0 | 0.08 | 0.2 |
| 24 | 50 | 32 | 41 | 24 | 0 | 0.08 | 0.1 |
| 25 | 50 | 32 | 41 | 24 | 0 | 0.08 | 0.1 |
| 26 | 51 | 32 | 42 | 24 | 0 | 0.08 | 0.1 |
| 27 | 51 | 33 | 42 | 23 | 0 | 0.09 | 0.2 |
| 28 | 52 | 33 | 42 | 23 | 0 | 0.09 | 0.1 |
| 29 | 52 | 33 | 42 | 23 | 0 | 0.09 | 0.1 |
| 30 | 52 | 34 | 43 | 22 | 0 | 0.09 | 0.1 |
| 31 | 53 | 34 | 43 | 22 | 0 | 0.10 | 0.1 |
| MONTH | 46.6 | 29.2 | 37.9 | 841 | 1 | 2.50 | 5.6 |
HDD = A Heating Degree Day represents the number of degree(s) that the mean temperature for the day is below 65 degrees during a day.
CDD = A Cooling Degree Day represents the number of degree(s) that the mean temperature for the day is above 65 degrees during a day.
CHICAGO O'HARE CURRENT AND HISTORY (3-DAY) ... | NWS Chicago Office OBSERVED WEATHER REPORTS



















