Boston vs Chicago: climate compared
Boston, Massachusetts and Chicago, Illinois, both measured the same way — 1991–2020 climate normals — so the numbers can be compared directly. This page compares the climate records only; neither city is scored against anyone’s preferences here.
The main differences
- Boston’s warmest month is 2.3°F (1.3°C) warmer than Chicago’s (82°F (27.8°C) against 79.7°F (26.5°C) average highs).
- Winter nights are 0.9°F (0.5°C) milder in Boston: its coldest month averages lows of 19.8°F (-6.8°C), against 18.9°F (-7.3°C) in Chicago.
At a glance
| Measure | Boston | Chicago |
|---|---|---|
| Warmest-month high | 82°F (28°C) | 80°F (27°C) |
| Coldest-month high | 35°F (2°C) | 30°F (-1°C) |
| Coldest-month low | 20°F (-7°C) | 19°F (-7°C) |
| Gap between warmest and coldest month | 47.0°F (26.1°C) | 49.7°F (27.6°C) |
| Most humid month (dew point) | 62°F (17°C)noticeably humid | 64°F (18°C)noticeably humid |
| Rain a year | 44.4 in (1128 mm) | 37.9 in (962 mm) |
| Wet days a year | 119 | 121 |
| Sunshine, hours a day | 8.6 | 8.8 |
| Snow a year | 42 in (106.6 cm) | 28.1 in (71.4 cm) |
| Days above 90°F (32°C) | 8 | 2 |
| Freezing nights a year | 108 | 110 |
Temperature through the year
Average daily highs and lows by month, on one shared scale.
Month by month
| Month | Boston high / low | Chicago high / low | Boston wet days | Chicago wet days |
|---|---|---|---|---|
| January | 35°F (2°C) / 20°F (-7°C) | 30°F (-1°C) / 19°F (-7°C) | 10 | 9 |
| February | 38°F (3°C) / 21°F (-6°C) | 32°F (0°C) / 20°F (-7°C) | 9 | 8 |
| March | 45°F (7°C) / 28°F (-2°C) | 40°F (5°C) / 29°F (-2°C) | 11 | 10 |
| April | 56°F (13°C) / 39°F (4°C) | 51°F (11°C) / 40°F (4°C) | 11 | 12 |
| May | 66°F (19°C) / 49°F (10°C) | 64°F (18°C) / 52°F (11°C) | 11 | 12 |
| June | 76°F (24°C) / 59°F (15°C) | 75°F (24°C) / 63°F (17°C) | 10 | 12 |
| July | 82°F (28°C) / 66°F (19°C) | 80°F (27°C) / 69°F (21°C) | 10 | 12 |
| August | 80°F (27°C) / 65°F (18°C) | 78°F (26°C) / 68°F (20°C) | 9 | 11 |
| September | 73°F (23°C) / 58°F (14°C) | 71°F (22°C) / 61°F (16°C) | 8 | 9 |
| October | 61°F (16°C) / 47°F (8°C) | 59°F (15°C) / 49°F (9°C) | 10 | 10 |
| November | 50°F (10°C) / 37°F (3°C) | 46°F (8°C) / 37°F (3°C) | 10 | 9 |
| December | 40°F (5°C) / 27°F (-3°C) | 35°F (2°C) / 26°F (-3°C) | 11 | 9 |
Averages for a typical year, not a forecast for any particular one. Methodology
Which would suit you?
Score both against your own preferences, or read each city’s full record.
Boston vs Chicago climate: weather compared month by month