Boston, MA climate: monthly averages and frost dates
Boston, MA has cold winters and warm summers by this site's scale, with wet annual precipitation. The figures are the 1991–2020 climate normals for NOAA station USW00014739 (BOSTON LOGAN INTL AP), 2 mi (2 km) in a straight line from the city's center point (US Census).
- Warmest month high
- 82.1°F
- July
- Coldest month mean
- 29.9°F
- January
- Precipitation
- 43.6 in
- per year
- Snowfall
- 49.2 in
- per year
- Median last frost
- April 4
- 32°F, spring
- Median first frost
- November 9
- 32°F, autumn
Monthly averages in Boston
| Month | High °F | Low °F | Mean °F | Precip. in | Snow in | Days ≥0.01 in | Days ≥90°F | Nights ≤32°F |
|---|---|---|---|---|---|---|---|---|
| January | 36.8 | 23.1 | 29.9 | 3.39 | 14.3 | 11.8 | 0.0 | 24.8 |
| February | 39.0 | 24.6 | 31.8 | 3.21 | 14.4 | 10.6 | 0.0 | 21.7 |
| March | 45.5 | 31.1 | 38.3 | 4.17 | 9.0 | 11.6 | 0.0 | 16.2 |
| April | 56.4 | 40.8 | 48.6 | 3.63 | 1.6 | 11.6 | 0.1 | 2.1 |
| May | 66.5 | 50.3 | 58.4 | 3.25 | 0.0 | 11.8 | 0.6 | 0.0 |
| June | 76.2 | 59.7 | 68.0 | 3.89 | 0.0 | 10.9 | 2.5 | 0.0 |
| July | 82.1 | 66.0 | 74.1 | 3.27 | 0.0 | 9.4 | 6.3 | 0.0 |
| August | 80.4 | 65.1 | 72.7 | 3.23 | 0.0 | 9.0 | 3.8 | 0.0 |
| September | 73.1 | 58.2 | 65.6 | 3.56 | 0.0 | 9.0 | 0.8 | 0.0 |
| October | 62.1 | 47.5 | 54.8 | 4.03 | 0.2 | 10.5 | 0.0 | 0.2 |
| November | 51.6 | 37.9 | 44.7 | 3.66 | 0.7 | 10.3 | 0.0 | 6.8 |
| December | 42.2 | 29.2 | 35.7 | 4.30 | 9.0 | 11.9 | 0.0 | 19.8 |
| Year | 59.3 | 44.5 | 51.9 | 43.59 | 49.2 | 128.4 | 14.1 | 91.6 |
How cold is winter in Boston?
Winters in Boston are cold by this site's scale (coldest-month mean 20 to under 32°F). The coldest month is January, with a mean temperature of 29.9°F (−1.2°C), a normal daily high of 36.8°F (2.7°C) and a normal daily low of 23.1°F (−4.9°C).
The station averages 91.6 nights a year at or below 32°F and 23.1 days when the high stays at or below 32°F.
The normal daily low is at or below freezing in December to March.
How hot is summer in Boston?
Summers in Boston are warm by this site's scale (hottest-month high 80 to under 90°F). July has the highest normal daily high, 82.1°F (27.8°C), with nights averaging 66.0°F (18.9°C).
The high reaches 90°F or more on 14.1 days in a normal year.
What is the wettest month in Boston?
Boston gets 43.59 in (1107 mm) of precipitation in a normal year, which this site classes as wet (40 to under 60 in a year). The wettest month is December with 4.30 in (109 mm); the driest is February with 3.21 in (82 mm).
Measurable precipitation (0.01 in or more) falls on 128.4 days a year.
Does it snow in Boston?
Normal annual snowfall in Boston is 49.2 in (125 cm), which this site classes as heavy (36 to under 72 in a year).
February is the snowiest month, with 14.4 in (37 cm).
A day with 1.0 in or more of snowfall comes 11.1 times a year on average.
Which months are mild in Boston?
5 months in Boston meet this site's comfort thresholds (normal high 65–85°F, low 45°F or higher, fewer than 10 days with 0.10 in or more of precipitation): May to September.
Thresholds and their limits: methodology.
Frost dates and growing season in Boston
In Boston the median last spring night at or below 32°F is April 4, and the median first autumn one is November 9 (NOAA P50 dates). NOAA's median length of the freeze-free season is 218 days. NOAA takes that median over each year's own season, so it need not equal the 219 days between the two median dates.
There is still a 10% chance of a 32°F night on or after April 17, and a 10% chance that the first one has come by October 29.
The chance that the last spring 32°F night comes on or after March 25 is 90%.
For a hard freeze (28°F or lower) the median dates are March 28 in spring and November 21 in autumn.
| Chance | Last spring 32°F night on or after | First autumn 32°F night by | Freeze-free season, days |
|---|---|---|---|
| 10% | April 17 | October 29 | 235 |
| 20% | April 11 | November 1 | 230 |
| 30% | April 8 | November 3 | 225 |
| 40% | April 6 | November 6 | 221 |
| 50% | April 4 | November 9 | 218 |
| 60% | April 3 | November 12 | 214 |
| 70% | April 1 | November 14 | 211 |
| 80% | March 30 | November 17 | 207 |
| 90% | March 25 | November 22 | 201 |
| Threshold | Median last date (spring) | Median first date (autumn or winter) | Median season, days |
|---|---|---|---|
| 36°F | April 17 | October 29 | 194 |
| 32°F | April 4 | November 9 | 218 |
| 28°F | March 28 | November 21 | 239 |
| 24°F | March 19 | December 1 | 258 |
| 20°F | March 11 | December 11 | 275 |
| 16°F | March 2 | December 23 | 294 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 100% | 100% | 100% | 74% | 0% | 0% | 0% | 0% | 0% | 15% | 96% | 100% |
Nearby and similar places
Of the places on this site, the closest to Boston by station distance are Burlington, VT at 181 mi (291 km), New York, NY at 188 mi (302 km) and Philadelphia, PA at 279 mi (449 km).
Among places whose winter, summer and precipitation words are each within one band of Boston's (winter: cold, summer: warm, precipitation: wet), the closest monthly temperature and precipitation patterns are Buffalo, NY, Philadelphia, PA and New York, NY.
Compared with Burlington, VT, Boston's peak-month normal high is 0.3°F (0.2°C) lower, its coldest-month mean is 9.0°F (5.0°C) higher, and its annual precipitation is 6.06 in more.
| Place | Listed as | Station distance | Coldest mean °F | Warmest high °F | Precip. in/yr | Snow in/yr | Last frost |
|---|---|---|---|---|---|---|---|
| Boston, MA | this page | – | 29.9 | 82.1 | 43.6 | 49.2 | April 4 |
| Burlington, VT | nearby | 181 mi (291 km) | 20.9 | 82.4 | 37.5 | 87.5 | April 29 |
| New York, NY | nearby, similar | 188 mi (302 km) | 33.7 | 84.9 | 49.5 | 29.8 | March 30 |
| Philadelphia, PA | nearby, similar | 279 mi (449 km) | 33.7 | 87.8 | 44.1 | 23.1 | April 2 |
| Buffalo, NY | similar | 395 mi (635 km) | 25.5 | 80.2 | 40.7 | 95.4 | April 24 |
How nearby and similar places are chosen: methodology.
Source and station
The data for Boston come from NOAA station BOSTON LOGAN INTL AP, MA US (USW00014739) at 42.3606, -71.0106, elevation 12 ft (4 m). It lies 2 mi (2 km) in a straight line from the center point of Boston city, the “internal point” in the US Census 2024 Gazetteer.
Each monthly normal used here rests on at least 27 years of data from 1991–2020 (NOAA's per-field year counts).
NOAA completeness flags on the monthly fields used here:
- S: Standard: meets WMO standards for data availability for 24 or more years.
Cite the data as:
Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020). Station USW00014739 (BOSTON LOGAN INTL AP, MA US). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/wck8-er13. Accessed 2026-10-09.
Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020). Station USW00014739 (BOSTON LOGAN INTL AP, MA US). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/4ek7-fk11. Accessed 2026-10-09.
Files used: monthly normals CSV, annual/seasonal normals CSV (retrieved 2026-10-09). The values on this page as JSON: /us/ma/boston/data.json.