Coupeville, Washington climate: Normal weather by month, frost dates and records
Coupeville's normal year runs from 36°F December nights to 71°F August afternoons, with 21.7 inches of precipitation and 3 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, December lows of 2°C, August highs of 21°C, 552 mm of precipitation a year.
- NOAA stationCoupeville (1 mi S)
- Station IDUSC00451783
- Location48.21°N 122.69°W
- Elevation50 ft (15 m)
- From the center1 miles
- Population1,935
On October 23, the normal high in Coupeville is 54°F and the normal low 43°F, and the chance of measurable rain or snow is 42%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Coupeville.
- Jan 44° 37°
- Feb 47° 36°
- Mar 51° 38°
- Apr 57° 42°
- May 62° 47°
- Jun 65° 50°
- Jul 70° 53°
- Aug 71° 53°
- Sep 66° 49°
- Oct 56° 45°
- Nov 49° 40°
- Dec 44° 36°
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 Coupeville each month?
August is the warmest month, with normal highs of 71°F; December the coldest, with normal lows of 36°F. The most precipitation falls in November (3.12 in), the least in August (0.70 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 44°F | 37°F | 40.4°F | 2.50 | 0.0 | 16 | <1 | 7 | 8 h 50 min |
| February | 47°F | 36°F | 41.5°F | 1.91 | 0.0 | 12 | <1 | 8 | 10 h 10 min |
| March | 51°F | 38°F | 44.7°F | 1.96 | 0.3 | 14 | <1 | 4 | 11 h 50 min |
| April | 57°F | 42°F | 49.1°F | 1.87 | 0.0 | 12 | <1 | <1 | 13 h 40 min |
| May | 62°F | 47°F | 54.2°F | 1.73 | 0.0 | 9 | <1 | <1 | 15 h 10 min |
| June | 65°F | 50°F | 57.7°F | 1.31 | 0.0 | 9 | <1 | <1 | 16 h |
| July | 70°F | 53°F | 61.4°F | 0.78 | 0.0 | 4 | <1 | <1 | 15 h 40 min |
| August | 71°F | 53°F | 61.6°F | 0.70 | 0.0 | 4 | <1 | <1 | 14 h 20 min |
| September | 66°F | 49°F | 57.6°F | 1.22 | 0.0 | 8 | <1 | <1 | 12 h 40 min |
| October | 56°F | 45°F | 50.5°F | 2.08 | 0.0 | 12 | <1 | 1 | 11 h |
| November | 49°F | 40°F | 44.1°F | 3.12 | 0.6 | 16 | <1 | 4 | 9 h 20 min |
| December | 44°F | 36°F | 39.9°F | 2.56 | 1.6 | 16 | <1 | 8 | 8 h 20 min |
| Year (annual) | 57°F | 44°F | 50.2°F | 21.74 | 2.5 | 131 | 1 | 32 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 7°C | 3°C | 4.7°C | 64 mm | 0 cm |
| February | 8°C | 2°C | 5.3°C | 49 mm | 0 cm |
| March | 11°C | 4°C | 7.1°C | 50 mm | 1 cm |
| April | 14°C | 5°C | 9.5°C | 47 mm | 0 cm |
| May | 17°C | 8°C | 12.3°C | 44 mm | 0 cm |
| June | 18°C | 10°C | 14.3°C | 33 mm | 0 cm |
| July | 21°C | 12°C | 16.3°C | 20 mm | 0 cm |
| August | 21°C | 12°C | 16.4°C | 18 mm | 0 cm |
| September | 19°C | 10°C | 14.2°C | 31 mm | 0 cm |
| October | 14°C | 7°C | 10.3°C | 53 mm | 0 cm |
| November | 9°C | 4°C | 6.7°C | 79 mm | 2 cm |
| December | 6°C | 2°C | 4.4°C | 65 mm | 4 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451783; 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 Coupeville?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, August 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 USC00451783.
When is the last frost in Coupeville?
In Coupeville, the last spring frost (32°F) comes after March 17 in half of years and after April 3 in one year in ten; the first autumn frost comes before November 11 in half of years and before October 21 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
- March 171 year in 10 after April 3; 9 in 10 after February 24
- First autumn frost, half of years before
- November 111 year in 10 before October 21; 9 in 10 before December 1
NOAA puts the median frost-free season at 237 days, and the season without a hard freeze (28°F) at 281 days.
A hard freeze (28°F) comes after February 21 in half of springs and before November 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Coupeville in zone 8b in ZIP code 98239, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Coupeville's NOAA station is in zone 8b: the coldest night of a typical year reaches 20°F (17 complete years).
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00451783; 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 in Coupeville?
In a normal year in Coupeville, 1 day a year reaches 90°F, 32 nights fall to 32°F or colder and 131 days bring measurable precipitation.
- Days at 90°F or more
- 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 32a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 131a normal year
- Days with 1 inch of snow or more
- 1a normal year
The highest temperature in this station's record (since 1895) is 98°F, on August 8, 1960; the lowest is 3°F, on January 25, 1950.
The wettest calendar year on that record is 1971, with 29.18 in; the snowiest season is 1949–50, with 30.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00451783; records: ACIS (NOAA Regional Climate Centers), station USC00451783. Records use complete months only; a month missing more than three days is left out.
How sunny is Coupeville?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Coupeville, 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 much heating and cooling does Coupeville need?
A normal year in Coupeville brings 5,402 heating degree days, 1% more than the median U.S. place (5,373), and 22 cooling degree days, 98% 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 1,420 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 763 | 0 |
| February | 659 | 0 |
| March | 631 | 0 |
| April | 477 | 0 |
| May | 337 | 0 |
| June | 221 | 2 |
| July | 122 | 11 |
| August | 113 | 7 |
| September | 223 | 1 |
| October | 451 | 0 |
| November | 627 | 0 |
| December | 778 | 0 |
| Year (annual) | 5,402 | 22 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451783. 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.
Has Coupeville been warmer than normal lately?
Over 65 complete years from 1896 to 2018, the station's annual mean temperature rose at a fitted 0.8°F per century (+0.05°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Coupeville's climate compare?
Coupeville is warmer than 44 of the other 95 places with their own NOAA record in Washington, and wetter than 45. Across the 7,247 U.S. stations with normals, its annual mean of 50.2°F is warmer than 41%.
In the Köppen classification computed from these normals, Coupeville 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 Coupeville share this climate record?
Camano has no NOAA station with 1991-2020 normals of its 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.
- Camano, WA17,535 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 Coupeville's climate
What is the coldest month in Coupeville?
December, with a normal high of 44°F and a normal low of 36°F. The warmest is August (71°F by day, 53°F at night).
Does it snow in Coupeville?
Yes: 3 inches in a normal year, falling on 1 days with 0.1 inch or more, the most in December (1.6 inches).
What is the rainiest month in Coupeville?
November, with 3.12 in of precipitation in a normal year; the driest is August with 0.70 in.
What plant hardiness zone is Coupeville in?
The USDA's 2023 map puts Coupeville in zone 8b in ZIP code 98239, the nearest ZIP area. By the same method at Coupeville's NOAA station, the coldest night of a typical year reaches 20°F (17 years, 1991-2020): zone 8b.
How late can frost come in Coupeville?
In half of years the last 32°F night comes after March 17; in one year in ten it comes after April 3. Waiting until April 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Port Townsend, WA7 miles from this station, 51.9°F a year
- Whidbey Island Naval Air Station, WA10 miles from this station, 52.1°F a year
- Sequim, WA19 miles from this station, 48.9°F a year
- Mount Vernon, WA21 miles from this station, 51.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made