Boston is at its most pleasant from August to early October, and again from late May to early July. For sun, aim for mid July to early August; for walking, go from mid September to early November.
When to go five ratings · thirty-six ten-day sections · click a cell to read it
The sun season here runs from mid July to early August. It peaks in mid July, at 62. The weakest stretch is from mid October to early May, when it drops to 0, mostly because it is too cool. The clearest skies come in August, when the sky is typically 46% covered at midday (partly cloudy).
For being outside, go from August to early October, with a second spell from late May to early July. It peaks in mid September, at 78. Avoid mid November to early April for this: it falls to 0, mostly because it is too cold.
The walking season here runs from mid September to early November, with a second spell from late April to mid June. It peaks in mid October, at 81. The weakest stretch is from January to mid February, when it drops to 3, mostly because it is too cold.
The year, measured
The average temperature in Boston over the whole year is 11°C. July is the hottest month, with highs of about 27°C; January is the coldest, with lows of about -3°C. Boston has no sharply defined rainy season: the chance of rain on a given day runs from 13% in August, the driest month, to 19% in April, the wettest. Winds in Boston are highest in March, averaging 3.7 m/s (13 km/h), and lightest in August, at 2.4 m/s (9 km/h). The prevailing wind is from the W. The clearest skies in Boston come in August, when the sky is typically 41% covered; April is the cloudiest month, at 53%.
Month by month Boston climate by month: average temperatures year round · click a month to read it
| Month | High | Low | Feels like | Chance of rain | Cloud | Wind | Being outside | Sun | Walking |
|---|---|---|---|---|---|---|---|---|---|
| January | 1°C | -3°C | -4°C | 16% | 52% | 3.4 m/s | 0 | 0 | 5 |
| February | 3°C | -2°C | -3°C | 17% | 50% | 3.3 m/s | 2 | 0 | 11 |
| March | 7°C | 1°C | 1°C | 16% | 50% | 3.7 m/s | 3 | 0 | 21 |
| April | 12°C | 6°C | 7°C | 19% | 53% | 3.5 m/s | 12 | 1 | 46 |
| May | 18°C | 12°C | 14°C | 16% | 53% | 3.1 m/s | 43 | 9 | 71 |
| June | 24°C | 17°C | 22°C | 14% | 47% | 2.8 m/s | 72 | 29 | 54 |
| July | 27°C | 21°C | 27°C | 13% | 43% | 2.6 m/s | 49 | 58 | 22 |
| August | 26°C | 19°C | 26°C | 13% | 41% | 2.4 m/s | 61 | 50 | 31 |
| September | 22°C | 15°C | 21°C | 14% | 47% | 2.5 m/s | 72 | 23 | 61 |
| October | 17°C | 10°C | 13°C | 16% | 51% | 2.7 m/s | 44 | 4 | 74 |
| November | 10°C | 4°C | 5°C | 16% | 43% | 3.1 m/s | 10 | 0 | 36 |
| December | 4°C | -0°C | -1°C | 19% | 49% | 3.1 m/s | 0 | 0 | 11 |
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Boston weather by season
Year round, Boston has days of about 1°C at their warmest in January, its coolest month, and 27°C in July, its warmest; the coolest hours of the day run from -3°C to 21°C through the year, and the average temperature over the year is 11°C around the clock. Rain is most likely around April and least likely around August. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Boston weather in winterDecember to February
Winter in Boston has typical daily highs of about 3°C and lows of about -2°C, with a 17% chance of rain on a given day.
Boston weather in springMarch to May
Spring in Boston has typical daily highs of about 12°C and lows of about 6°C, with a 17% chance of rain on a given day.
Boston weather in summerJune to August
Summer in Boston has typical daily highs of about 25°C and lows of about 19°C, with a 13% chance of rain on a given day.
Boston weather in autumnSeptember to November
Autumn in Boston has typical daily highs of about 16°C and lows of about 10°C, with a 16% chance of rain on a given day.
When is the rainy season in Boston?
Boston has no sharply defined rainy season: the chance of rain on a given day runs from 13% in August, the driest month, to 19% in April, the wettest.
What time of year is Boston windiest?
Winds in Boston are highest in March, averaging 3.7 m/s (13 km/h), and lightest in August, at 2.4 m/s (9 km/h). The prevailing wind is from the W.
What is the average temperature in Boston year round?
The average temperature in Boston over the whole year is 11°C. July is the hottest month, with highs of about 27°C; January is the coldest, with lows of about -3°C.
Where to go instead in early January, the weakest time here for being outside
How this is worked out
Every figure is a decade of weather-station observations blended into one typical year, in ten-day sections. The ratings, the chart and the feels-like column are read at midday local solar time. Being outside is the Easy outdoors rating, Sun is Sunbathing and Walking is Active outdoors, each out of 100: Good from 55, Ideal from 80. They describe what a time of year is usually like here, not a forecast. The dotted links open the map at that time of year; set its time of day to midday to see these numbers.