Massachusetts weather and outdoor projects
Massachusetts has cold winters, warm summers and rain or snow spread through the year. Boston and the coast are moderated by the ocean, with sea breezes on warm days, while Worcester and the central hills are colder, with an earlier first frost and a later last frost.
Late May to June and September are the best months for staining and painting. Nor’easters can bring several days of wind and rain in spring and fall. Many homes have older wood siding and trim, and fall painting is common, as long as nights stay above the paint’s minimum. New concrete needs good curing to survive winter freeze-thaw cycles and road salt.
Frost dates in Massachusetts
In Boston, the median last spring freeze (32°F) is around April 4 and the median first fall freeze is around November 9, a frost-free season of about 218 days.
In Worcester, the median last spring freeze (32°F) is around April 23 and the median first fall freeze is around October 21, a frost-free season of about 181 days.
How Massachusetts compares with other states
Boston is tied for the 7th-longest deck staining season of the 50 state main stations (5 good months). Boston has the 7th-most humid summer afternoons of the 47 state main stations (56% humidity at 3 PM, June–August). Boston is tied for the 10th-fewest days at 90°F or hotter of the 50 state main stations (14 a year).
| Measure (Boston) | Value | Rank, highest first |
|---|---|---|
| Deck staining season | 5 good months | 7th of 50 |
| Frost-free season | 218 days | 20th of 50 |
| Freezing nights | 92 a year | 26th of 50 |
| Rainy days | 77 a year with 0.1 in or more | 16th of 50 |
| Days at 90°F or hotter | 14 a year | 40th of 50 |
| Summer afternoons | 56% humidity at 3 PM, June–August | 7th of 47 |
Best time to stain a deck in Massachusetts
In Boston, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 56°F, Oct 62°F). November–March is too cold, with average highs around 43°F. April is cool, with highs around 56°F, so choose the warmest afternoons. In October, nights average about 48°F, so finish early on mild days and check the overnight low.
In Worcester, the most reliable months are June–September. May and October can also work on the right days (average highs May 67°F, Oct 59°F). November–March is too cold, with average highs around 39°F. In April, nights average about 37°F, too cold for the coating to dry and cure overnight. In May, nights average about 47°F, so finish early on mild days and check the overnight low. October is cool, with highs around 59°F, so choose the warmest afternoons.
Best time to paint outside in Massachusetts
In Boston, the most reliable months are May–October. April and November can also work on the right days (average highs Apr 56°F, Nov 52°F). December–March is too cold, with average highs around 41°F. April and November are cool, with highs around 54°F, so choose the warmest afternoons.
In Worcester, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 56°F, Oct 59°F). November–March is too cold, with average highs around 39°F. April is cool, with highs around 56°F, so choose the warmest afternoons. In October, nights average about 42°F, so finish early on mild days and check the overnight low.
Best time to pour concrete in Massachusetts
In Boston, the most reliable months are May–October. April and November can also work on the right days (average highs Apr 56°F, Nov 52°F). December–March averages about 21 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. April and November bring about 4 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
In Worcester, the most reliable months are May–September. October can also work on the right days (average highs Oct 59°F). November–April averages about 21 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. October brings about 3 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
Best time to seal a driveway in Massachusetts
In Boston, the most reliable months are June–September. May and October can also work on the right days (average highs May 67°F, Oct 62°F). November–April is too cold, with average highs around 45°F. May and October are cool, with highs around 64°F, so choose the warmest afternoons.
In Worcester, the most reliable months are June–September. May can also work on the right days (average highs May 67°F). October–April is too cold, with average highs around 44°F. May is cool, with highs around 67°F, so choose the warmest afternoons.
Best time to fertilize or treat a lawn in Massachusetts
In Boston, the most reliable months are May–October. April and November can also work on the right days (average highs Apr 56°F, Nov 52°F). December–March is too cold, with average highs around 41°F. April and November are cool, with highs around 54°F, so choose the warmest afternoons.
In Worcester, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 56°F, Oct 59°F). November–March is too cold, with average highs around 39°F. April and October are cool, with highs around 57°F, so choose the warmest afternoons.
How the weather differs across Massachusetts
| Place | Hottest month avg high | Coldest month avg low | Rain per year | Last spring freeze | First fall freeze |
|---|---|---|---|---|---|
| Boston | 82°F | 23°F | 44 in | April 4 | November 9 |
| Worcester | 80°F | 17°F | 48 in | April 23 | October 21 |
Of the places above, Boston has the most good months for staining, painting and concrete combined (17 job-months), and Worcester has the fewest (14).
Monthly weather in Boston
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 37°F | 23°F | 7 | 3.4 in | 53% | 25 |
| February | 39°F | 25°F | 6 | 3.2 in | 49% | 22 |
| March | 46°F | 31°F | 7 | 4.2 in | 50% | 16 |
| April | 56°F | 41°F | 7 | 3.6 in | 50% | 2 |
| May | 67°F | 50°F | 7 | 3.3 in | 54% | 0 |
| June | 76°F | 60°F | 7 | 3.9 in | 56% | 0 |
| July | 82°F | 66°F | 6 | 3.3 in | 55% | 0 |
| August | 80°F | 65°F | 5 | 3.2 in | 57% | 0 |
| September | 73°F | 58°F | 6 | 3.6 in | 58% | 0 |
| October | 62°F | 48°F | 6 | 4.0 in | 56% | 0 |
| November | 52°F | 38°F | 6 | 3.7 in | 54% | 7 |
| December | 42°F | 29°F | 7 | 4.3 in | 56% | 20 |
*Days with 0.1 inch of rain or more; column notes.
Monthly weather in Worcester
| Month | Avg high | Avg low | Wet days* | Rain | Freezing nights |
|---|---|---|---|---|---|
| January | 32°F | 17°F | 7 | 3.5 in | 28 |
| February | 35°F | 19°F | 7 | 3.3 in | 26 |
| March | 43°F | 26°F | 7 | 4.2 in | 24 |
| April | 56°F | 37°F | 8 | 4.1 in | 8 |
| May | 67°F | 47°F | 8 | 3.6 in | 0 |
| June | 75°F | 56°F | 8 | 4.2 in | 0 |
| July | 80°F | 62°F | 7 | 3.9 in | 0 |
| August | 78°F | 61°F | 6 | 4.1 in | 0 |
| September | 71°F | 53°F | 6 | 4.2 in | 0 |
| October | 59°F | 42°F | 7 | 4.8 in | 3 |
| November | 48°F | 33°F | 7 | 4.0 in | 15 |
| December | 38°F | 23°F | 8 | 4.3 in | 26 |
Source: NOAA NCEI U.S. Climate Normals 1991–2020 for BOSTON LOGAN INTL AP, WORCESTER RGNL AP. See how the ratings work and how late in fall you can stain, paint or seal.
Frequently asked questions
When is the best time to stain a deck in Massachusetts?
In Boston, May–September. In Worcester, June–September.
When is the last frost in Massachusetts?
Boston: around April 4; Worcester: around April 23.
Can you pour concrete in winter in Massachusetts?
Yes, with cold-weather practices: Boston averages about 66 freezing nights from December to February, so fresh concrete needs insulated blankets, a heated enclosure or an accelerated mix, and must not freeze in the first 48 hours. Many homeowners wait for spring.
What months are best for sealing a driveway in Massachusetts?
In Boston, June–September. In Worcester, June–September.