Coos Bay, Oregon climate: Normal weather by month, frost dates and records
Coos Bay's normal year runs from 36°F December nights to 66°F August afternoons, with 65.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.3°C, December lows of 2°C, August highs of 19°C, 1,660 mm of precipitation a year.
- NOAA stationCoos Bay (8 mi SW)
- Station IDUSW00004141
- Location43.27°N 124.32°W
- Elevation12 ft (4 m)
- Population15,801
On October 23, the normal high in Coos Bay is 61°F and the normal low 41°F, and the chance of measurable rain or snow is 50%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Coos Bay.
- Jan 52° 36°
- Feb 54° 37°
- Mar 56° 38°
- Apr 57° 39°
- May 60° 44°
- Jun 62° 47°
- Jul 64° 51°
- Aug 66° 50°
- Sep 66° 47°
- Oct 63° 42°
- Nov 56° 39°
- Dec 51° 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 Coos Bay each month?
August is the warmest month, with normal highs of 66°F; December the coldest, with normal lows of 36°F. The most precipitation falls in December (10.90 in), the least in August (0.46 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 52°F | 36°F | 43.9°F | 10.71 | 18 | <1 | 11 | 9 h 20 min |
| February | 54°F | 37°F | 45.3°F | 8.50 | 19 | <1 | 10 | 10 h 30 min |
| March | 56°F | 38°F | 46.5°F | 8.45 | 21 | <1 | 8 | 11 h 50 min |
| April | 57°F | 39°F | 48.1°F | 5.50 | 19 | <1 | 3 | 13 h 20 min |
| May | 60°F | 44°F | 51.9°F | 2.87 | 16 | <1 | 1 | 14 h 40 min |
| June | 62°F | 47°F | 54.7°F | 2.45 | 12 | <1 | <1 | 15 h 20 min |
| July | 64°F | 51°F | 57.2°F | 0.51 | 7 | <1 | <1 | 15 h 10 min |
| August | 66°F | 50°F | 58.0°F | 0.46 | 8 | <1 | <1 | 14 h |
| September | 66°F | 47°F | 56.3°F | 1.77 | 8 | <1 | <1 | 12 h 30 min |
| October | 63°F | 42°F | 52.2°F | 4.23 | 14 | <1 | 3 | 11 h 10 min |
| November | 56°F | 39°F | 47.5°F | 8.99 | 19 | <1 | 6 | 9 h 40 min |
| December | 51°F | 36°F | 43.8°F | 10.90 | 20 | <1 | 12 | 9 h |
| Year (annual) | 59°F | 42°F | 50.5°F | 65.34 | 181 | <1 | 54 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 11°C | 2°C | 6.6°C | 272 mm |
| February | 12°C | 3°C | 7.4°C | 216 mm |
| March | 13°C | 3°C | 8.1°C | 215 mm |
| April | 14°C | 4°C | 8.9°C | 140 mm |
| May | 15°C | 7°C | 11.1°C | 73 mm |
| June | 17°C | 8°C | 12.6°C | 62 mm |
| July | 18°C | 10°C | 14.0°C | 13 mm |
| August | 19°C | 10°C | 14.4°C | 12 mm |
| September | 19°C | 8°C | 13.5°C | 45 mm |
| October | 17°C | 5°C | 11.2°C | 107 mm |
| November | 13°C | 4°C | 8.6°C | 228 mm |
| December | 11°C | 2°C | 6.6°C | 277 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Coquille (8 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 USW00004141; 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 Coos Bay?
Normal highs sit between 65°F and 85°F in August and September. Of those, September has the fewest days with rain (8).
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 USW00004141.
When is the last frost in Coos Bay?
In Coos Bay, the last spring frost (32°F) comes after April 15 in half of years and after May 3 in one year in ten; the first autumn frost comes before October 31 in half of years and before October 8 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 151 year in 10 after May 3; 9 in 10 after March 23
- First autumn frost, half of years before
- October 311 year in 10 before October 8; 9 in 10 before November 29
NOAA puts the median frost-free season at 199 days, and the season without a hard freeze (28°F) at 277 days.
A hard freeze (28°F) comes after February 27 in half of springs and before November 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Coos Bay in zone 9a in ZIP code 97420, the nearest ZIP area.
Frost dates for every NOAA station in Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00004141; 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 Coos Bay?
In a normal year in Coos Bay, a 90°F day is rare, 54 nights fall to 32°F or colder and 181 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 54a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 181a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USW00004141.
How sunny is Coos Bay?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Coos Bay, 3.9 kWh per square metre a day. July is the sunniest month (81%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.5 |
| February | 64% | 2.3 |
| March | 65% | 3.4 |
| April | 69% | 4.8 |
| May | 73% | 5.9 |
| June | 75% | 6.4 |
| July | 81% | 6.6 |
| August | 79% | 5.6 |
| September | 78% | 4.5 |
| October | 72% | 2.9 |
| November | 63% | 1.7 |
| December | 58% | 1.2 |
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 Coos Bay need?
A normal year in Coos Bay brings 5,295 heating degree days, 1% fewer than the median U.S. place (5,373), and 0 cooling degree days, 100% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,091 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 653 | 0 |
| February | 550 | 0 |
| March | 574 | 0 |
| April | 506 | 0 |
| May | 406 | 0 |
| June | 309 | 0 |
| July | 242 | 0 |
| August | 216 | 0 |
| September | 261 | 0 |
| October | 397 | 0 |
| November | 527 | 0 |
| December | 656 | 0 |
| Year (annual) | 5,295 | 0 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00004141. 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 Coos Bay been warmer than normal lately?
2025 averaged 50.5°F, equal to the 1991-2020 normal of 50.5°F. 1 of the 2 complete years since 2024 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2024 | 51.6°F | +1.1°F | 82.51 |
| 2025 | 50.5°F | at normal | 58.52 |
Source: observed years: ACIS, station USW00004141. A year counts only with all twelve months complete.
How does Coos Bay's climate compare?
Coos Bay is warmer than 38 of the other 104 places with their own NOAA record in Oregon, and wetter than 80. Across the 7,247 U.S. stations with normals, its annual mean of 50.5°F is warmer than 43%.
In the Köppen classification computed from these normals, Coos Bay 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 Coos Bay share this climate record?
Barview 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.
- Barview, OR1,645 people · 5 mi N
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 Coos Bay's climate
What is the coldest month in Coos Bay?
December, with a normal high of 51°F and a normal low of 36°F. The warmest is August (66°F by day, 50°F at night).
Does it snow in Coos Bay?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Coos Bay's NOAA station; the nearest record that keeps one, Coquille (8 miles away), records 0 inches of snow in a normal year.
What is the rainiest month in Coos Bay?
December, with 10.90 in of precipitation in a normal year; the driest is August with 0.46 in.
What plant hardiness zone is Coos Bay in?
The USDA's 2023 map puts Coos Bay in zone 9a in ZIP code 97420, the nearest ZIP area.
How late can frost come in Coos Bay?
In half of years the last 32°F night comes after April 15; in one year in ten it comes after May 3. Waiting until May 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Coos Bay in OctoberThis month day by day, its records and recent years
- Oregon climateThe statewide normals and every place in the state
- Coquille, OR8 miles from this station, 53.2°F a year
- Bandon, OR9 miles from this station, 53.2°F a year
- North Bend, OR11 miles from this station, 53.0°F a year
- Langlois, OR25 miles from this station, 52.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made