Cascadia, Oregon climate: Normal weather by month, frost dates and records
Cascadia's normal year runs from 33°F December nights to 79°F July afternoons, with 63.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, December lows of 0°C, July highs of 26°C, 1,602 mm of precipitation a year.
- NOAA stationCascadia
- Station IDUSC00351433
- Location44.39°N 122.48°W
- Elevation960 ft (293 m)
- Population (census place)103
On October 23, the normal high in Cascadia is 59°F and the normal low 38°F, and the chance of measurable rain or snow is 45%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Cascadia.
- Jan 45° 33°
- Feb 50° 33°
- Mar 54° 34°
- Apr 58° 37°
- May 65° 42°
- Jun 70° 46°
- Jul 79° 49°
- Aug 80° 48°
- Sep 74° 44°
- Oct 62° 39°
- Nov 50° 35°
- Dec 44° 33°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Cascadia each month?
July is the warmest month, with normal highs of 79°F; December the coldest, with normal lows of 33°F. The most precipitation falls in December (9.64 in), the least in July (0.61 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 45°F | 33°F | 38.9°F | 7.90 | 19 | <1 | 16 | 9 h 10 min |
| February | 50°F | 33°F | 41.3°F | 6.31 | 16 | <1 | 14 | 10 h 30 min |
| March | 54°F | 34°F | 43.9°F | 7.10 | 18 | <1 | 12 | 11 h 50 min |
| April | 58°F | 37°F | 47.6°F | 6.27 | 18 | <1 | 5 | 13 h 20 min |
| May | 65°F | 42°F | 53.5°F | 4.60 | 14 | <1 | 2 | 14 h 50 min |
| June | 70°F | 46°F | 57.7°F | 3.09 | 10 | 1 | <1 | 15 h 30 min |
| July | 79°F | 49°F | 64.0°F | 0.61 | 4 | 3 | <1 | 15 h 10 min |
| August | 80°F | 48°F | 63.7°F | 0.88 | 4 | 3 | <1 | 14 h 10 min |
| September | 74°F | 44°F | 58.9°F | 2.27 | 6 | 1 | 1 | 12 h 40 min |
| October | 62°F | 39°F | 50.6°F | 5.48 | 13 | <1 | 5 | 11 h |
| November | 50°F | 35°F | 42.8°F | 8.94 | 18 | <1 | 11 | 9 h 40 min |
| December | 44°F | 33°F | 38.2°F | 9.64 | 19 | <1 | 15 | 8 h 50 min |
| Year (annual) | 61°F | 39°F | 50.1°F | 63.09 | 159 | 8 | 79 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 7°C | 0°C | 3.8°C | 201 mm |
| February | 10°C | 0°C | 5.2°C | 160 mm |
| March | 12°C | 1°C | 6.6°C | 180 mm |
| April | 15°C | 3°C | 8.7°C | 159 mm |
| May | 18°C | 6°C | 11.9°C | 117 mm |
| June | 21°C | 8°C | 14.3°C | 78 mm |
| July | 26°C | 10°C | 17.8°C | 15 mm |
| August | 27°C | 9°C | 17.6°C | 22 mm |
| September | 23°C | 7°C | 14.9°C | 58 mm |
| October | 17°C | 4°C | 10.3°C | 139 mm |
| November | 10°C | 2°C | 6.0°C | 227 mm |
| December | 7°C | 0°C | 3.4°C | 245 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Foster Dam (10 miles away), gets 0 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00351433; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Cascadia?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, July has the fewest days with rain (4).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00351433.
When is the last frost in Cascadia?
In Cascadia, the last spring frost (32°F) comes after April 29 in half of years and after May 17 in one year in ten; the first autumn frost comes before October 13 in half of years and before September 22 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 291 year in 10 after May 17; 9 in 10 after April 5
- First autumn frost, half of years before
- October 131 year in 10 before September 22; 9 in 10 before November 6
NOAA puts the median frost-free season at 167 days, and the season without a hard freeze (28°F) at 220 days.
A hard freeze (28°F) comes after March 30 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Cascadia in zone 8b in ZIP code 97345.
Frost dates for every NOAA station in Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00351433; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Cascadia?
In a normal year in Cascadia, 8 days a year reach 90°F, 79 nights fall to 32°F or colder and 159 days bring measurable precipitation.
- Days at 90°F or more
- 8a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 79a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 159a normal year
The highest temperature in this station's record (since 1918) is 106°F, on July 20, 1946; the lowest is −2°F, on December 8, 1972.
The wettest calendar year on that record is 1996, with 94.16 in; the snowiest season is 1950–51, with 35.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00351433; records: ACIS (NOAA Regional Climate Centers), station USC00351433. Records use complete months only; a month missing more than three days is left out.
How sunny is Cascadia?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Cascadia, 3.9 kWh per square metre a day. July is the sunniest month (89%) and December the cloudiest (53%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 56% | 1.3 |
| February | 61% | 2.2 |
| March | 59% | 3.1 |
| April | 64% | 4.5 |
| May | 70% | 5.7 |
| June | 74% | 6.4 |
| July | 89% | 7.4 |
| August | 88% | 6.3 |
| September | 81% | 4.6 |
| October | 70% | 2.8 |
| November | 58% | 1.5 |
| December | 53% | 1.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Cascadia need?
A normal year in Cascadia brings 5,540 heating degree days, 3% more than the median U.S. place (5,373), and 118 cooling degree days, 87% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,647 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 809 | 0 |
| February | 665 | 0 |
| March | 653 | 0 |
| April | 521 | 0 |
| May | 360 | 3 |
| June | 227 | 8 |
| July | 81 | 50 |
| August | 86 | 46 |
| September | 196 | 11 |
| October | 445 | 0 |
| November | 668 | 0 |
| December | 831 | 0 |
| Year (annual) | 5,540 | 118 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00351433. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Cascadia's climate compare?
Cascadia is warmer than 35 of the other 104 places with their own NOAA record in Oregon, and wetter than 79. Across the 7,247 U.S. stations with normals, its annual mean of 50.1°F is warmer than 40%.
In the Köppen classification computed from these normals, Cascadia is Csb: temperate, dry-summer, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Cascadia's climate
What is the coldest month in Cascadia?
December, with a normal high of 44°F and a normal low of 33°F. The warmest is July (79°F by day, 49°F at night).
Does it snow in Cascadia?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Cascadia's NOAA station; the nearest record that keeps one, Foster Dam (10 miles away), records 0 inches of snow in a normal year.
What is the rainiest month in Cascadia?
December, with 9.64 in of precipitation in a normal year; the driest is July with 0.61 in.
What plant hardiness zone is Cascadia in?
The USDA's 2023 map puts Cascadia in zone 8b in ZIP code 97345.
How late can frost come in Cascadia?
In half of years the last 32°F night comes after April 29; in one year in ten it comes after May 17. Waiting until May 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Foster Dam, OR9 miles from this station, 52.4°F a year
- Lacomb, OR20 miles from this station, 51.4°F a year
- Cougar Dam, OR22 miles from this station, 57.3°F a year
- Leaburg (1 mi SW), OR22 miles from this station, 53.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made