Mountlake Terrace, WA climate
Mountlake Terrace has mild winters and cool summers. A typical July afternoon reaches 75°, a January night drops to 36°, and about 4 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Mountlake Terrace feels like
Winter
Spring
Summer
Fall
Mountlake Terrace 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 | 46° | 36° | 4.9" | 0.9" | 19 | 1 | 37° – 46° |
| February | 49° | 36° | 3.6" | 1.0" | 16 | 1 | 35° – 47° |
| March | 53° | 38° | 4.2" | 0 | 18 | 0 | 41° – 50° |
| April | 58° | 41° | 3.0" | 0 | 16 | 0 | 45° – 55° |
| May | 64° | 47° | 2.2" | 0 | 12 | 0 | 51° – 60° |
| June | 69° | 51° | 1.7" | 0 | 11 | 0 | 57° – 65° |
| July | 75° | 55° | 0.8" | 0 | 5 | 0 | 61° – 69° |
| August | 75° | 55° | 1.0" | 0 | 6 | 0 | 61° – 67° |
| September | 70° | 51° | 1.7" | 0 | 9 | 0 | 57° – 63° |
| October | 59° | 45° | 3.8" | 0 | 15 | 0 | 49° – 57° |
| November | 51° | 39° | 5.3" | 0.2" | 19 | 0 | 41° – 50° |
| December | 45° | 35° | 5.4" | 1.7" | 20 | 1 | 36° – 43° |
| Year | 59° | 44° | 37.6" | 3.8" | 163 | 2 |
“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 Mountlake Terrace
Mountlake Terrace gets 38 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 163 days a year.
About 259 frost-free days a year
In half of years the last 32° night comes by March 8 and the first one by November 23. That leaves about 259 frost-free days for gardens, longer than 92% of U.S. towns.
Heating and cooling a home in Mountlake Terrace
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Mountlake Terrace, 96% of that work is heating and 4% 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.
Mountlake Terrace and its neighbors
Mountlake Terrace borders 4 towns with climate data. January nights across them vary by 0.1°. Brier has the coldest January nights (36°) and Edmonds the hottest July afternoons (75°). Mountlake Terrace’s January low is 36° and its July high 75°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Mountlake Terrace 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 Mountlake Terrace averaged 1.1° warmer than the 1900s. The biggest change is in January (+2.4°). The shift is smaller than in 63% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Mountlake Terrace’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 35° to 47°. September is the most reliable, staying within 6°.
Common questions about Mountlake Terrace’s climate
What is the coldest month in Mountlake Terrace?
December, with a typical high of 45° and a low of 35°.
What is the hottest month in Mountlake Terrace?
August, with a typical high of 75° and a low of 55°. About 2 days a year reach 90°.
How much snow does Mountlake Terrace get?
About 4 inches in a normal winter, most of it in December.
When is the first frost in Mountlake Terrace?
In half of years the first 32° night comes by November 23, and the last spring frost by March 8.
What is the rainiest month in Mountlake Terrace?
December, with 5.4 inches of rain and melted snow. The year totals 38 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Mountlake Terrace itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Seattle Sand Pt WSFO, WA (8 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.