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.
Frost dates matter for concrete, which must not freeze in its first 48 hours, for paint and caulk that need nights above their minimum, and for lawn care, since crabgrass preventer goes down as the soil warms in spring. See how late in fall you can stain, paint or seal.
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. 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. 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.
Check this week’s hour-by-hour verdict with the deck staining forecast.
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. 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. 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.
Check this week’s hour-by-hour verdict with the exterior painting forecast.
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. 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. 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.
Check this week’s hour-by-hour verdict with the concrete pouring forecast.
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. 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. October–April is too cold, with average highs around 44°F. May is cool, with highs around 67°F, so choose the warmest afternoons.
Check this week’s hour-by-hour verdict with the driveway sealing forecast.
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. 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. 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.
Check this week’s hour-by-hour verdict with the lawn fertilizer forecast.
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). If you live between them, expect something in between, and higher ground to be cooler with a shorter season.
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 at least 0.1 inch of rain or melted snow. Freezing nights: average nights a month at or below 32°F. Humidity is calculated from NOAA hourly normal temperature and dew point at 3 PM.
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 |
Use the averages, then check the forecast
These ratings describe a typical month, not a particular week. A warm spell in a “poor” month can give you a good day, and a wet week can spoil a “good” one. Use this page to plan the season, then check the 7-day forecast for your ZIP code before you buy materials or book help. Each project forecast checks the hours after you finish too: overnight lows, dew and rain that would ruin fresh stain, paint, sealer or concrete.
About this data
Monthly temperatures, rain days, snowfall and freeze dates are NOAA National Centers for Environmental Information (NCEI) U.S. Climate Normals for 1991–2020 at BOSTON LOGAN INTL AP, WORCESTER RGNL AP. Ratings apply the same temperature limits as our forecasts (for example, 50°F or warmer for deck stain and driveway sealer, and no freezing nights for new concrete) to the average month. Your product label always takes priority.
Frequently asked questions
When is the best time to stain a deck in Massachusetts?
In Boston, May–September. In Worcester, June–September. Look for at least 24 dry hours before and after, and nights above about 40°F. The deck staining forecast checks your exact week.
When is the last frost in Massachusetts?
Boston: around April 4; Worcester: around April 23. These are median dates from NOAA 1991–2020 normals, so a freeze after them happens in about half of years. Low spots and valleys freeze later in spring.
Can you pour concrete in winter in Massachusetts?
Yes, but it needs 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. Most sealers need 50°F or warmer for 24 hours and a dry day after. See the driveway sealing forecast.