Denver is 2.5°C (4.5°F) warmer by day, Boston has 2.4°C (4.3°F) warmer nights, Boston gets 751 mm (29.6 in) more rain a year.
Boston is at its warmest in July and coolest in January, while Denver peaks in July and bottoms out in January. Month for month, Boston is the warmer of the two in 8 of 12 months.
Boston is the wetter of the two, collecting 1,213 mm (47.8 in) of rain a year against 462 mm (18.2 in) in Denver. The most comfortable time to visit is June, July and August in Boston and June, July and August in Denver.
| Boston | Metric | Denver |
|---|---|---|
| 🌡️ Temperature | ||
| 57.4°F | 🌡️Average daytime high | 61.9°F |
| 40.1°F | 🌙Average nighttime low | 35.8°F |
| July | 🔥Hottest month | July |
| January | ❄️Coldest month | January |
| 🌧️ Rain | ||
| 47.8 in | 🌧️Annual rainfall | 18.2 in |
| October | ☔Wettest month | May |
| February | 🏜️Driest month | January |
| 💨 Climate | ||
| 80% | 💧Average humidity | 50% |
| 0.7 m/s | 💨Average wind speed | 2.5 m/s |
Overnight, Boston typically falls to around 4.5°C (40.1°F) while Denver settles near 2.1°C (35.8°F).
Boston is hottest in July and coldest in January, whereas Denver peaks in July and is coolest in January.
Boston sees the most rain in October and the least in February; Denver is wettest in May and driest in January.
Boston feels the more humid of the two, averaging 80% relative humidity against 50%.
For Denver, the pick of the year is June, July and August.
Month by month, here is the coldest night, the average day and the hottest afternoon each city can expect. Switch Compare to read rainfall, humidity, wind or solar instead, and Period to move between the long-term 45-year average and any single year — the shading is a quick warm-to-cool guide.
| Month | Boston | Denver | ||||
|---|---|---|---|---|---|---|
| Min | Avg | Max | Min | Avg | Max | |
| January | 17.8 | 25❄️ | 32.4 | 19.6 | 30.2❄️ | 40.6 |
| February | 19.4 | 27.1 | 34.9 | 20.5 | 31.8 | 43.2 |
| March | 26.4 | 34.7 | 43 | 25.3 | 37.9 | 50.7 |
| April | 35.8 | 45.1 | 54.5 | 30.6 | 44.6 | 58.5 |
| May | 46.4 | 55.9 | 65.5 | 40.1 | 54.3 | 68.7 |
| June | 55.9 | 65.1 | 74.3 | 50.7 | 65.8 | 81.1 |
| July | 62.4 | 71.8🔥 | 81.1 | 57.4 | 71.6🔥 | 85.6 |
| August | 61.3 | 71.1 | 80.8 | 55.9 | 69.4 | 82.9 |
| September | 54.1 | 64 | 73.8 | 47.5 | 61.9 | 76.3 |
| October | 43.7 | 52.5 | 61.5 | 35.4 | 49.5 | 63.3 |
| November | 33.8 | 41.5 | 49.3 | 26.2 | 38.3 | 50.4 |
| December | 24.8 | 31.5 | 38.1 | 20.1 | 30.6 | 40.8 |
| Annual Avg | 40.1 | 48.7 | 57.4 | 35.8 | 48.9 | 61.9 |
Min / mean / max temperature (°F). 🔥 marks each city's hottest month, ❄️ its coldest; shading runs cool blue to warm red.
The same figures plotted out, so the shape of a typical year is easier to see than in a grid. Where the two lines run close together Boston and Denver feel alike; where they separate, they are genuinely different places to be.
Hover or tap any point to read the exact figures. Boston Denver
See how Boston and Denver stack up against other cities. Swipe for more.
Choose which city to keep, then search for any other city in our database — we'll build the comparison for you.
Quick answers to the questions people ask most when comparing Boston and Denver — each drawn straight from the climate figures above.
Denver is the warmer of the two. It averages daytime highs of 16.6°C (61.9°F) against 14.1°C (57.4°F) in Boston — roughly 2.5°C (4.5°F) warmer by day. Nights are milder in Boston, with average lows of 4.5°C (40.1°F) versus 2.1°C (35.8°F).
Boston is hottest in July, averaging highs of about 27.3°C (81.1°F), while Denver peaks in July at around 29.8°C (85.6°F). That makes Denver the hotter of the two at the height of summer.
Boston gets colder. In its coldest month (January) overnight lows average about -7.9°C (17.7°F), compared with -6.9°C (19.7°F) at the low point of the year in Denver.
Boston is the wetter city, collecting about 1,213 mm (47.8 in) of rain a year versus 462 mm (18.2 in) in Denver. Boston is wettest in October and driest in February; Denver is wettest in May and driest in January.
Boston is the more humid of the two, averaging 80% relative humidity over the year against 50% in Denver.
The most comfortable months in Boston are June, July and August, when average temperatures are at their mildest.
Denver is at its most pleasant around June, July and August, based on the mildest average temperatures of the year.
Boston is the warmer city in 8 of the 12 months of the year. The gap is widest in January, about 2.9°C (5.2°F), and narrowest in July, about 0.1°C (0.2°F).
Boston has the bigger seasonal swing, about 26°C (46.8°F) between its coldest and hottest months versus 23°C (41.4°F) in Denver — so Denver has the steadier, more even climate.
On climate alone, Denver comes out ahead — it offers warmer days, less rain and lower humidity than Boston. Boston is the better fit only if you'd actually prefer cooler weather, more rainfall and a more humid climate.
Every figure on this page is calculated from NASA POWER satellite climate data spanning 1981–2025 (45 years). The averages describe the long-term climate of Boston and Denver, not a single year's weather or a short-range forecast.
