Carson, Washington climate: Normal weather by month, frost dates and records
Carson's normal year runs from 29°F December nights to 82°F August afternoons, with 88.9 inches of precipitation and 55 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.1°C, December lows of −2°C, August highs of 28°C, 2,258 mm of precipitation a year.
- NOAA stationCarson Fish Hatchery
- Station IDUSC00451160
- Location45.87°N 121.97°W
- Elevation1,134 ft (346 m)
- Population (census place)2,553
On October 14, the normal high in Carson is 61°F and the normal low 38°F, and the chance of measurable rain or snow is 36%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Carson.
- Jan 38° 29°
- Feb 43° 29°
- Mar 50° 31°
- Apr 57° 35°
- May 66° 41°
- Jun 72° 46°
- Jul 81° 49°
- Aug 82° 49°
- Sep 74° 44°
- Oct 60° 38°
- Nov 46° 33°
- Dec 38° 29°
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 Carson each month?
August is the warmest month, with normal highs of 82°F; December the coldest, with normal lows of 29°F. The most precipitation falls in December (15.84 in), the least in July (0.46 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 38°F | 29°F | 33.4°F | 14.46 | 18.5 | 20 | <1 | 25 | 9 h |
| February | 43°F | 29°F | 36.0°F | 11.29 | 8.5 | 15 | <1 | 21 | 10 h 20 min |
| March | 50°F | 31°F | 40.4°F | 9.78 | 5.0 | 18 | <1 | 21 | 11 h 50 min |
| April | 57°F | 35°F | 46.0°F | 6.14 | 0.4 | 16 | <1 | 10 | 13 h 30 min |
| May | 66°F | 41°F | 53.6°F | 3.34 | 0.0 | 11 | <1 | 2 | 14 h 50 min |
| June | 72°F | 46°F | 58.6°F | 2.18 | 0.0 | 8 | 1 | <1 | 15 h 40 min |
| July | 81°F | 49°F | 65.2°F | 0.46 | 0.0 | 2 | 7 | <1 | 15 h 20 min |
| August | 82°F | 49°F | 65.4°F | 0.77 | 0.0 | 3 | 7 | <1 | 14 h 10 min |
| September | 74°F | 44°F | 58.9°F | 2.81 | 0.0 | 5 | 2 | 1 | 12 h 40 min |
| October | 60°F | 38°F | 48.7°F | 8.05 | 0.1 | 12 | <1 | 7 | 11 h |
| November | 46°F | 33°F | 39.6°F | 13.78 | 3.1 | 18 | <1 | 15 | 9 h 30 min |
| December | 38°F | 29°F | 33.3°F | 15.84 | 19.4 | 20 | <1 | 25 | 8 h 40 min |
| Year (annual) | 59°F | 38°F | 48.3°F | 88.90 | 55.0 | 147 | 18 | 126 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −2°C | 0.8°C | 367 mm | 47 cm |
| February | 6°C | −2°C | 2.2°C | 287 mm | 22 cm |
| March | 10°C | 0°C | 4.7°C | 248 mm | 13 cm |
| April | 14°C | 2°C | 7.8°C | 156 mm | 1 cm |
| May | 19°C | 5°C | 12.0°C | 85 mm | 0 cm |
| June | 22°C | 8°C | 14.8°C | 55 mm | 0 cm |
| July | 27°C | 10°C | 18.4°C | 12 mm | 0 cm |
| August | 28°C | 9°C | 18.6°C | 20 mm | 0 cm |
| September | 23°C | 7°C | 14.9°C | 71 mm | 0 cm |
| October | 15°C | 3°C | 9.3°C | 204 mm | 0 cm |
| November | 8°C | 1°C | 4.2°C | 350 mm | 8 cm |
| December | 3°C | −2°C | 0.7°C | 402 mm | 49 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451160; 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 Carson?
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 (2).
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 USC00451160.
When is the last frost in Carson?
In Carson, the last spring frost (32°F) comes after May 2 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 9 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
- May 21 year in 10 after May 20; 9 in 10 after April 15
- First autumn frost, half of years before
- October 91 year in 10 before September 22; 9 in 10 before November 1
NOAA puts the median frost-free season at 161 days, and the season without a hard freeze (28°F) at 208 days.
A hard freeze (28°F) comes after April 7 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Carson in zone 8a in ZIP code 98648, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Carson's NOAA station is in zone 8a: the coldest night of a typical year reaches 12°F (22 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 USC00451160; 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 Carson?
In a normal year in Carson, 18 days a year reach 90°F (1 of them 100°F or more), 126 nights fall to 32°F or colder and 147 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 126a normal year
- Days that stay below freezing
- 10high of 32°F or less
- Days with 0.01 inch of precipitation
- 147a normal year
- Days with 1 inch of snow or more
- 16a normal year
The highest temperature in this station's record (since 1977) is 109°F, on June 29, 2021; the lowest is −2°F, on November 23, 1985.
The wettest calendar year on that record is 1996, with 134.81 in; the snowiest season is 1992–93, with 156.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00451160; records: ACIS (NOAA Regional Climate Centers), station USC00451160. Records use complete months only; a month missing more than three days is left out.
How sunny is Carson?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Carson, 4.2 kWh per square metre a day. July is the sunniest month (93%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 57% | 1.3 |
| February | 66% | 2.3 |
| March | 68% | 3.5 |
| April | 75% | 5.1 |
| May | 78% | 6.3 |
| June | 83% | 7.1 |
| July | 93% | 7.7 |
| August | 91% | 6.5 |
| September | 86% | 4.8 |
| October | 76% | 3.0 |
| November | 64% | 1.6 |
| December | 56% | 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 Carson need?
A normal year in Carson brings 6,291 heating degree days, 17% more than the median U.S. place (5,373), and 207 cooling degree days, 77% 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 1,725 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 980 | 0 |
| February | 812 | 0 |
| March | 761 | 0 |
| April | 572 | 0 |
| May | 358 | 4 |
| June | 210 | 20 |
| July | 78 | 84 |
| August | 71 | 82 |
| September | 200 | 17 |
| October | 505 | 0 |
| November | 762 | 0 |
| December | 983 | 0 |
| Year (annual) | 6,291 | 207 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00451160. 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 Carson been warmer than normal lately?
2023 averaged 48.8°F, 0.5°F above the 1991-2020 normal of 48.3°F. 1 of the 2 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2022 | 48.1°F | −0.2°F | – | – |
| 2023 | 48.8°F | +0.5°F | – | – |
Source: observed years: ACIS, station USC00451160. A year counts only with all twelve months complete.
How does Carson's climate compare?
Carson is warmer than 17 of the other 95 places with their own NOAA record in Washington, and wetter than 85. Across the 7,247 U.S. stations with normals, its annual mean of 48.3°F is warmer than 33%.
In the Köppen classification computed from these normals, Carson 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 Carson's climate
What is the coldest month in Carson?
December, with a normal high of 38°F and a normal low of 29°F. The warmest is August (82°F by day, 49°F at night).
Does it snow in Carson?
Yes: 55 inches in a normal year, falling on 23 days with 0.1 inch or more, the most in December (19.4 inches).
What is the rainiest month in Carson?
December, with 15.84 in of precipitation in a normal year; the driest is July with 0.46 in.
What plant hardiness zone is Carson in?
The USDA's 2023 map puts Carson in zone 8a in ZIP code 98648, the nearest ZIP area. By the same method at Carson's NOAA station, the coldest night of a typical year reaches 12°F (22 years, 1991-2020): zone 8a.
How late can frost come in Carson?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 20. Waiting until May 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Cascade Locks, OR14 miles from this station, 52.6°F a year
- Bonneville Dam, OR16 miles from this station, 52.8°F a year
- Cougar, WA17 miles from this station, 52.5°F a year
- Skamania Fish Hatchery, WA21 miles from this station, 50.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made