Photo: M.O. Stevens · Public domainSummer arrives softly in Bull Mountain, cooler than in 85% of U.S. towns
Deep winter brings January lows near 36°. Its January nights stay gentler than in 83% of U.S. towns. The latest 30-year average runs 1.2° warmer than 1901–2000’s, with January up the most. Seedlings are safe outdoors from about April 1, with the first autumn frost due around November 6.
A year in Bull Mountain at a glance
Each month’s typical high and low, and what it brings.
What stands out about Bull Mountain’s climate
Compared with towns across the U.S., with Bull Mountain’s place in Oregon beside it.
What a year in Bull Mountain feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 222 frost-free days a year
In half of years the last 32° night comes by April 1 and the first by November 6. Frost and day counts come from NOAA’s station at Beaverton 2 Ssw, OR, 3.0 miles from the town’s center, 220 ft lower.
The 2023 USDA map puts Bull Mountain’s center in zone 8b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 18°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 4 inches of snow a winter
Snow, measured at Portland Kgw-tv, OR, is heaviest from January through February, about 1 inches a month. Precipitation (rain plus melted snow) adds up to 40 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 155 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Bull Mountain
93% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Beaverton 2 Ssw, OR.
Living with Bull Mountain’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
222 frost-free days in zone 8b. The last frost comes by Apr 1 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 6.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 0.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Bull Mountain from natural hazards, river flooding is the largest share (45%); heat waves, cold waves, winter storms and ice storms together are 11%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Bull Mountain and its neighbors
Every town next door is within a degree of Bull Mountain in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Bull Mountain’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Bull Mountain, OR | 36° | 81° | 40" | 3.6" |
| Mercer Island, WA | 37° | 77° | 37" | 3.8" |
| Scotts Valley, CA | 39° | 79° | 37" | 0.0" |
| Brigantine, NJ | 28° | 83° | 45" | 10" |
| Swannanoa, NC | 27° | 83° | 48" | 2.1" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Bull Mountain averaged 1.2° warmer than the 1900s. The biggest change is in January (+2.8°).
A smaller shift than in 63% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Bull Mountain compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Bull Mountain’s place among Oregon’s.
Bull Mountain weather by month
Highs, lows and precipitation from NOAA’s grid at Bull Mountain’s center; snow, wet days and snow on the ground from Portland Kgw-tv, OR. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 47° | 36° | 5.7" | 1.3" | 20 | 1 | 35° – 46° |
| February | 51° | 36° | 4.2" | 1.4" | 16 | 1 | 37° – 49° |
| March | 56° | 39° | 4.3" | 0.0" | 18 | 0 | 44° – 52° |
| April | 61° | 41° | 3.1" | 0.0" | 17 | 0 | 47° – 56° |
| May | 69° | 47° | 2.3" | 0.0" | 12 | 0 | 52° – 62° |
| June | 74° | 51° | 1.5" | 0.0" | 9 | 0 | 59° – 68° |
| July | 81° | 55° | 0.4" | 0.0" | 3 | 0 | 63° – 72° |
| August | 82° | 55° | 0.5" | 0.0" | 3 | 0 | 65° – 72° |
| September | 76° | 51° | 1.5" | 0.0" | 7 | 0 | 60° – 66° |
| October | 64° | 44° | 3.6" | 0.0" | 13 | 0 | 50° – 58° |
| November | 53° | 39° | 5.9" | 0.0" | 19 | 0 | 40° – 51° |
| December | 46° | 35° | 6.8" | 0.9" | 20 | 0 | 36° – 44° |
| Year | 63° | 44° | 39.7" | 3.6" | 155 | 2 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 37° to 49°. September is the most reliable, staying within 6°.
Where Bull Mountain’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Bull Mountain’s center.
- Snow: Portland Kgw-tv, OR.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Beaverton 2 Ssw, OR, 3.0 miles from the town’s center, 220 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Bull Mountain’s climate
What is the weather like in Bull Mountain?
A typical July afternoon reaches 81°, a January night drops to 36°, and about 4 inches of snow falls in a normal winter. Milder January nights than 83% of U.S. towns; cooler July afternoons than 85% of U.S. towns.
How cold does it get in Bull Mountain in winter?
December nights average 35°. About 42 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 36°.
How much snow does Bull Mountain get?
About 3.6 inches in a normal winter at Portland Kgw-tv, OR, heaviest from January through February, about 1 inches a month, with snow on the ground about 2 days a year.
How hot does it get in Bull Mountain?
July, with a typical high of 81° and a low of 55°. About 15 days a year reach 90° and 1 reach 100° (Beaverton 2 Ssw, OR).
When is the first and last frost in Bull Mountain?
In half of years the last spring frost (32°) comes by April 1 and the first fall frost by November 6, about 222 frost-free days, at Beaverton 2 Ssw, OR.
What growing zone is Bull Mountain in?
Zone 8b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 18°.
What is the best time of year to visit Bull Mountain?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Bull Mountain getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 63% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Bull Mountain.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.