Watertown, MA climate
Watertown has chilly, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 84°, a January night drops to 19°, and about 64 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Watertown feels like
Winter
Spring
Summer
Fall
Watertown weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 19° | 3.6" | 17.2" | 12 | 18 | 19° – 35° |
| February | 39° | 20° | 3.4" | 16.2" | 11 | 18 | 16° – 36° |
| March | 47° | 27° | 4.4" | 13.3" | 13 | 13 | 31° – 45° |
| April | 59° | 37° | 4.1" | 2.2" | 13 | 1 | 44° – 52° |
| May | 69° | 47° | 3.6" | 0 | 13 | 0 | 52° – 63° |
| June | 78° | 56° | 4.2" | 0 | 12 | 0 | 63° – 70° |
| July | 84° | 62° | 3.6" | 0 | 11 | 0 | 68° – 77° |
| August | 82° | 61° | 3.6" | 0 | 9 | 0 | 68° – 76° |
| September | 75° | 53° | 3.9" | 0 | 10 | 0 | 61° – 68° |
| October | 63° | 41° | 4.7" | 0.1" | 11 | 0 | 49° – 59° |
| November | 52° | 33° | 3.9" | 1.7" | 11 | 1 | 37° – 47° |
| December | 42° | 24° | 4.6" | 12.8" | 13 | 11 | 27° – 43° |
| Year | 61° | 40° | 47.6" | 63.5" | 138 | 62 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Watertown
Watertown gets 48 inches of rain and melted snow a year. October is the wettest month and February the driest. Rain or snow falls on about 138 days a year. Snow covers the ground about 62 days of the year.
About 174 frost-free days a year
In half of years the last 32° night comes by April 25 and the first one by October 17. That leaves about 174 frost-free days for gardens, shorter than 56% of U.S. towns.
Heating and cooling a home in Watertown
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Watertown, 89% of that work is heating and 11% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Watertown and its neighbors
Watertown borders 5 towns with climate data. January nights across them vary by 2.8°. Waltham has the coldest January nights (18°) and Newton the hottest July afternoons (84°). Watertown’s January low is 19° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Watertown compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Watertown averaged 2.1° warmer than the 1900s. The biggest change is in December (+3.6°). The shift is larger than in 95% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Watertown’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 16° to 36°. June is the most reliable, staying within 7°.
Common questions about Watertown’s climate
What is the coldest month in Watertown?
January, with a typical high of 37° and a low of 19°.
What is the hottest month in Watertown?
July, with a typical high of 84° and a low of 62°. About 12 days a year reach 90°.
How much snow does Watertown get?
About 64 inches in a normal winter, most of it in January.
When is the first frost in Watertown?
In half of years the first 32° night comes by October 17, and the last spring frost by April 25.
What is the rainiest month in Watertown?
October, with 4.7 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Watertown itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Reading, MA (11 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.