Clearbrook, Washington climate: Climate normals at a NOAA weather station
Clearbrook's normal year runs from 32°F December nights to 76°F July afternoons, with 49.9 inches of precipitation and 11 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.2°C, December lows of 0°C, July highs of 24°C, 1,266 mm of precipitation a year.
- NOAA stationClearbrook
- Station IDUSC00451484
- Location48.97°N 122.33°W
- Elevation64 ft (20 m)
On October 23, the normal high in Clearbrook is 56°F and the normal low 41°F, and the chance of measurable rain or snow is 54%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Clearbrook.
- Jan 44° 32°
- Feb 48° 33°
- Mar 53° 36°
- Apr 59° 39°
- May 66° 45°
- Jun 70° 49°
- Jul 76° 51°
- Aug 77° 50°
- Sep 71° 47°
- Oct 59° 42°
- Nov 49° 36°
- Dec 43° 32°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Clearbrook each month?
July is the warmest month, with normal highs of 76°F; December the coldest, with normal lows of 32°F. The most precipitation falls in November (7.11 in), the least in July (1.45 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 44°F | 32°F | 37.8°F | 6.98 | 3.1 | 18 | <1 | 13 | 8 h 40 min |
| February | 48°F | 33°F | 40.4°F | 3.85 | 2.7 | 15 | <1 | 11 | 10 h 10 min |
| March | 53°F | 36°F | 44.3°F | 5.00 | 1.0 | 19 | <1 | 7 | 11 h 50 min |
| April | 59°F | 39°F | 49.2°F | 3.97 | 0.1 | 16 | <1 | 2 | 13 h 40 min |
| May | 66°F | 45°F | 55.5°F | 3.17 | 0.0 | 12 | <1 | <1 | 15 h 10 min |
| June | 70°F | 49°F | 59.7°F | 2.39 | 0.0 | 12 | <1 | <1 | 16 h 10 min |
| July | 76°F | 51°F | 63.6°F | 1.45 | 0.0 | 6 | 1 | <1 | 15 h 50 min |
| August | 77°F | 50°F | 63.4°F | 1.50 | 0.0 | 6 | 1 | <1 | 14 h 30 min |
| September | 71°F | 47°F | 58.7°F | 2.93 | 0.0 | 9 | <1 | <1 | 12 h 40 min |
| October | 59°F | 42°F | 50.5°F | 5.31 | 0.0 | 16 | <1 | 3 | 10 h 50 min |
| November | 49°F | 36°F | 42.7°F | 7.11 | 1.3 | 19 | <1 | 8 | 9 h 10 min |
| December | 43°F | 32°F | 37.5°F | 6.19 | 2.6 | 19 | <1 | 13 | 8 h 20 min |
| Year (annual) | 60°F | 41°F | 50.3°F | 49.85 | 10.8 | 168 | 2 | 57 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 6°C | 0°C | 3.2°C | 177 mm | 8 cm |
| February | 9°C | 1°C | 4.7°C | 98 mm | 7 cm |
| March | 12°C | 2°C | 6.8°C | 127 mm | 3 cm |
| April | 15°C | 4°C | 9.6°C | 101 mm | 0 cm |
| May | 19°C | 7°C | 13.1°C | 81 mm | 0 cm |
| June | 21°C | 10°C | 15.4°C | 61 mm | 0 cm |
| July | 24°C | 11°C | 17.6°C | 37 mm | 0 cm |
| August | 25°C | 10°C | 17.4°C | 38 mm | 0 cm |
| September | 22°C | 8°C | 14.8°C | 74 mm | 0 cm |
| October | 15°C | 5°C | 10.3°C | 135 mm | 0 cm |
| November | 10°C | 2°C | 5.9°C | 181 mm | 3 cm |
| December | 6°C | 0°C | 3.1°C | 157 mm | 7 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451484; 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.
Which months are mildest at Clearbrook?
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 (6).
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 USC00451484.
When is the last frost at Clearbrook?
In Clearbrook, the last spring frost (32°F) comes after April 18 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 18 in half of years and before September 28 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 181 year in 10 after May 5; 9 in 10 after March 27
- First autumn frost, half of years before
- October 181 year in 10 before September 28; 9 in 10 before November 8
NOAA puts the median frost-free season at 185 days, and the season without a hard freeze (28°F) at 235 days.
A hard freeze (28°F) comes after March 18 in half of springs and before November 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Clearbrook in zone 8a in ZIP code 98276, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 8b: the coldest night of a typical year reaches 15°F (29 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00451484; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 at Clearbrook?
In a normal year in Clearbrook, 2 days a year reach 90°F, 57 nights fall to 32°F or colder and 168 days bring measurable precipitation.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 57a normal year
- Days that stay below freezing
- 7high of 32°F or less
- Days with 0.01 inch of precipitation
- 168a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1903) is 106°F, on June 28, 2021; the lowest is −4°F, on January 13, 1911.
The wettest calendar year on that record is 1972, with 62.51 in; the snowiest season is 1936–37, with 47.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00451484; records: ACIS (NOAA Regional Climate Centers), station USC00451484. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Clearbrook?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds at Clearbrook, 3.5 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (51%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 52% | 1.0 |
| February | 61% | 1.9 |
| March | 61% | 2.9 |
| April | 67% | 4.3 |
| May | 71% | 5.5 |
| June | 72% | 6.0 |
| July | 82% | 6.5 |
| August | 81% | 5.5 |
| September | 76% | 3.9 |
| October | 64% | 2.2 |
| November | 55% | 1.1 |
| December | 51% | 0.8 |
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 many heating and cooling degree days does Clearbrook record?
A normal year at Clearbrook brings 5,426 heating degree days, 1% more than the median U.S. place (5,373), and 72 cooling degree days, 92% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,712 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 843 | 0 |
| February | 689 | 0 |
| March | 642 | 0 |
| April | 476 | 0 |
| May | 298 | 2 |
| June | 167 | 8 |
| July | 74 | 30 |
| August | 75 | 27 |
| September | 192 | 4 |
| October | 448 | 0 |
| November | 669 | 0 |
| December | 854 | 0 |
| Year (annual) | 5,426 | 72 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451484. 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.
Have recent years at Clearbrook been warmer than normal?
2022 averaged 50.3°F, equal to the 1991-2020 normal of 50.3°F. 1 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 50.7°F | +0.4°F | 51.33 | – |
| 2022 | 50.3°F | at normal | 45.62 | – |
Over 102 complete years from 1904 to 2024, the station's annual mean temperature rose at a fitted 1.8°F per century (+0.10°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00451484; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Clearbrook's climate compare?
Clearbrook is warmer than 45 of the 96 places with their own NOAA record in Washington, and wetter than 69. Across the 7,247 U.S. stations with normals, its annual mean of 50.3°F is warmer than 42%.
In the Köppen classification computed from these normals, Clearbrook 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.
Which places near Clearbrook share this climate record?
9 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Lynden, WA16,783 people · 6 mi W
- Everson, WA3,169 people · 4 mi S
- Peaceful Valley, WA2,661 people · 8 mi E
- Sumas, WA1,683 people · 3 mi NE
- Nooksack, WA1,675 people · 3 mi S
- Kendall, WA810 people · 10 mi E
- Deming, WA594 people · 10 mi SE
- Glacier, WA292 people · 19 mi E
- Maple Falls, WA247 people · 11 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Clearbrook's climate
What is the coldest month at Clearbrook?
December, with a normal high of 43°F and a normal low of 32°F. The warmest is July (76°F by day, 51°F at night).
Does it snow at Clearbrook?
Yes: 11 inches in a normal year, falling on 6 days with 0.1 inch or more, the most in January (3.1 inches).
What is the rainiest month at Clearbrook?
November, with 7.11 in of precipitation in a normal year; the driest is July with 1.45 in.
What plant hardiness zone is Clearbrook in?
The USDA's 2023 map puts Clearbrook in zone 8a in ZIP code 98276, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 15°F (29 years, 1991-2020): zone 8b.
How late can frost come at Clearbrook?
In half of years the last 32°F night comes after April 18; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Bellingham, WA16 miles from this station, 51.2°F a year
- Blaine, WA21 miles from this station, 50.9°F a year
- Olga (2 mi SE), WA33 miles from this station, 50.8°F a year
- Sedro-Woolley, WA33 miles from this station, 51.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made