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 2.2°F (1.2°C) warmer than Chicago’s (84.7°F (29.3°C) against 82.6°F (28.1°C) average highs).
- Winter nights are 2.9°F (1.6°C) milder in Boston: its coldest month averages lows of 20.5°F (-6.4°C), against 17.6°F (-8°C) in Chicago.
At a glance
| Measure | Boston | Chicago |
|---|---|---|
| Warmest-month high | 85°F (29°C) | 83°F (28°C) |
| Coldest-month high | 37°F (3°C) | 32°F (0°C) |
| Coldest-month low | 20°F (-6°C) | 18°F (-8°C) |
| Gap between warmest and coldest month | 47.3°F (26.3°C) | 50.4°F (28.0°C) |
| Most humid month (dew point) | 62°F (17°C)noticeably humid | 64°F (18°C)noticeably humid |
| Rain a year | 45.8 in (1163 mm) | 38.6 in (980 mm) |
| Wet days a year | 103 | 100 |
| Sunshine, hours a day | 5.6 | 5.6 |
| Snow a year | 42 in (106.6 cm) | 28.1 in (71.4 cm) |
| Days above 90°F (32°C) | 17 | 8 |
| Freezing nights a year | 111 | 118 |
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 | 37°F (3°C) / 20°F (-6°C) | 32°F (0°C) / 18°F (-8°C) | 9 | 7 |
| February | 40°F (5°C) / 22°F (-6°C) | 37°F (3°C) / 21°F (-6°C) | 8 | 6 |
| March | 47°F (8°C) / 29°F (-2°C) | 46°F (8°C) / 30°F (-1°C) | 10 | 8 |
| April | 58°F (15°C) / 38°F (3°C) | 58°F (15°C) / 38°F (4°C) | 10 | 11 |
| May | 70°F (21°C) / 48°F (9°C) | 69°F (21°C) / 48°F (9°C) | 10 | 11 |
| June | 79°F (26°C) / 58°F (14°C) | 78°F (26°C) / 57°F (14°C) | 8 | 9 |
| July | 85°F (29°C) / 64°F (18°C) | 83°F (28°C) / 63°F (17°C) | 7 | 8 |
| August | 83°F (29°C) / 63°F (17°C) | 81°F (27°C) / 62°F (17°C) | 7 | 8 |
| September | 76°F (24°C) / 55°F (13°C) | 75°F (24°C) / 55°F (13°C) | 7 | 7 |
| October | 64°F (18°C) / 44°F (6°C) | 63°F (17°C) / 44°F (6°C) | 9 | 9 |
| November | 53°F (12°C) / 35°F (2°C) | 48°F (9°C) / 33°F (0°C) | 9 | 8 |
| December | 43°F (6°C) / 26°F (-3°C) | 36°F (2°C) / 23°F (-5°C) | 10 | 8 |
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