West Haven-Sylvan, OR climate
West Haven-Sylvan has mild winters and pleasant summers. A typical July afternoon reaches 80°, 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 West Haven-Sylvan feels like
Winter
Spring
Summer
Fall
West Haven-Sylvan 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° | 6.5" | 1.3" | 20 | 1 | 33° – 45° |
| February | 50° | 36° | 4.8" | 1.4" | 16 | 1 | 36° – 48° |
| March | 55° | 38° | 4.7" | 0 | 18 | 0 | 43° – 51° |
| April | 60° | 41° | 3.4" | 0 | 17 | 0 | 46° – 55° |
| May | 67° | 46° | 2.5" | 0 | 12 | 0 | 52° – 61° |
| June | 72° | 51° | 1.6" | 0 | 9 | 0 | 58° – 67° |
| July | 80° | 55° | 0.4" | 0 | 3 | 0 | 62° – 71° |
| August | 80° | 55° | 0.6" | 0 | 3 | 0 | 64° – 71° |
| September | 75° | 51° | 1.6" | 0 | 7 | 0 | 59° – 66° |
| October | 63° | 45° | 3.9" | 0 | 13 | 0 | 49° – 58° |
| November | 52° | 39° | 6.7" | 0 | 19 | 0 | 40° – 50° |
| December | 46° | 35° | 7.6" | 0.9" | 20 | 0 | 36° – 43° |
| Year | 62° | 44° | 44.1" | 3.6" | 155 | 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 West Haven-Sylvan
West Haven-Sylvan gets 44 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 155 days a year.
About 280 frost-free days a year
In half of years the last 32° night comes by February 25 and the first one by December 1. That leaves about 280 frost-free days for gardens, longer than 94% of U.S. towns.
Heating and cooling a home in West Haven-Sylvan
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In West Haven-Sylvan, 90% of that work is heating and 10% 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.
West Haven-Sylvan and its neighbors
West Haven-Sylvan borders 3 towns with climate data. January nights across them vary by 0.4°. Cedar Mill has the coldest January nights (36°) and Beaverton the hottest July afternoons (81°). West Haven-Sylvan’s January low is 36° and its July high 80°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How West Haven-Sylvan 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 West Haven-Sylvan averaged 1.2° warmer than the 1900s. The biggest change is in January (+2.9°). The shift is larger than in 51% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at West Haven-Sylvan’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 36° to 48°. September is the most reliable, staying within 6°.
Common questions about West Haven-Sylvan’s climate
What is the coldest month in West Haven-Sylvan?
December, with a typical high of 46° and a low of 35°.
What is the hottest month in West Haven-Sylvan?
August, with a typical high of 80° and a low of 55°. About 11 days a year reach 90°.
How much snow does West Haven-Sylvan get?
About 4 inches in a normal winter, most of it in February.
When is the first frost in West Haven-Sylvan?
In half of years the first 32° night comes by December 1, and the last spring frost by February 25.
What is the rainiest month in West Haven-Sylvan?
December, with 7.6 inches of rain and melted snow. The year totals 44 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for West Haven-Sylvan itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Portland Kgw-tv, OR (4 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.