Chief Joseph Dam, WA Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from Chief Joseph Dam's primary NOAA station, CHIEF JOSEPH DAM.
The climate verdict for Chief Joseph Dam
Dryness leads the climate profile for Chief Joseph Dam, Washington, with 10.8 inches of precipitation a year. NOAA records an annual average of 51°F. At 49/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 18% of scores.
- 51°F
- annual average temperature (NOAA normal)
- 49/100
- comfort score, above 18% of station-mapped location scores
- 10.8"
- annual precipitation · 28" snow
- 168 days
- growing season, frost-free days
Chief Joseph Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00451400 · Chief Joseph Dam, WA 51°F mean · 10.8" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-ARID · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 51°F
- RANK-MID #3,087
- PHOTO-FINISH ≈ Hartford Bradley
- PRCP-ARID 10.8"
- SWING-WIDE 46°F
- COMF-LOW 49/100
- LOAD-HEAT 5,874 HDD
- STN-1 USC00451400
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Hartford Bradley, CT (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every WA station list.
- Chief Joseph Dam (this station) 51°F
- Cold Marion, OH 51°F
- Hot Champaign, IL 51°F
- Near Hartford Bradley, CT 51°F
- Near Lawrence, MA 51°F
Climate Living Index · Chief Joseph Dam
Chief Joseph Dam: 35/100 · grade F
Chief Joseph Dam publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Chief Joseph Dam, not an official NOAA rating. Rankings still use Comfort Score 49/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 51.0°F · 16.5° from 67.5°F | 45/100 · D |
| Snowfall burden | 27.9 inches/year | 41/100 · D |
| Frost-free season | 168 days/year | 40/100 · D |
| Normal heat + freeze calendar | 172 calendar days | 31/100 · F |
| Precipitation balance | 10.8 in · 24.2 from 35 in | 15/100 · F |
Chief Joseph Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Chief Joseph Dam's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 74.6°F
- Coldest month
- 28.5°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Chief Joseph Dam sits across the climate record
Three NOAA fields for Chief Joseph Dam's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 45th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Drier than 92%
- Chief Joseph Dam's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 64th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Chief Joseph Dam compares across U.S. station-mapped locations
Chief Joseph Dam's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
49 18th percentile score exceeds 18% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Chief Joseph Dam's measured station temperature trend
MethodologyAcross 48 complete annual observations from 1952 to 2019, CHIEF JOSEPH DAM warmed at a fitted rate of 0.15°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Chief Joseph Dam primary station fitted change +0.15 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 34°F (1°C) | 23°F (-5°C) | 29°F (-2°C) | 1.4" | 8.5" | 27.6 | 0.0 |
| February | 42°F (5°C) | 25°F (-4°C) | 33°F (1°C) | 0.9" | 3.1" | 23.1 | 0.0 |
| March | 54°F (12°C) | 32°F (0°C) | 43°F (6°C) | 1.1" | 0.6" | 16.6 | 0.0 |
| April | 64°F (18°C) | 38°F (3°C) | 51°F (11°C) | 0.6" | 0.0" | 6.3 | 0.0 |
| May | 74°F (23°C) | 46°F (8°C) | 60°F (16°C) | 0.9" | 0.0" | 1.0 | 1.6 |
| June | 81°F (27°C) | 52°F (11°C) | 66°F (19°C) | 0.8" | 0.0" | 0.0 | 5.3 |
| July | 91°F (33°C) | 58°F (15°C) | 75°F (24°C) | 0.5" | 0.0" | 0.0 | 18.6 |
| August | 90°F (32°C) | 58°F (14°C) | 74°F (23°C) | 0.2" | 0.0" | 0.0 | 17.7 |
| September | 80°F (27°C) | 49°F (10°C) | 65°F (18°C) | 0.3" | 0.0" | 0.1 | 4.7 |
| October | 63°F (17°C) | 38°F (3°C) | 50°F (10°C) | 0.8" | 0.0" | 6.5 | 0.0 |
| November | 45°F (7°C) | 30°F (-1°C) | 37°F (3°C) | 1.2" | 2.2" | 18.8 | 0.0 |
| December | 35°F (1°C) | 23°F (-5°C) | 29°F (-2°C) | 2.0" | 13.5" | 27.7 | 0.0 |
The year, day by day
Chief Joseph Dam works both ends of the calendar. Normal highs climb to 94°F by July 28 and hold at or above 90°F on 38 dates, then normal lows drop to freezing or below on 134 dates, bottoming at 22°F around January 1.
When the heat sits
Normal highs reach 90°F from July 12 through August 18, covering 38 dates. The broader mild season, normal highs of 70°F or more, runs May 3 to October 4.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
The freezing stretch
The normal low stays at or below 32°F into March 17, then returns to freezing around November 5, covering 134 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is December 23, when 36% of years recorded at least a hundredth of an inch. The driest is August 18 at 7%. Summed across the calendar, that is about 72 wet dates a year.
The widest day
July 25 carries the biggest normal gap between afternoon and dawn, 33°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Chief Joseph Dam.
Where Chief Joseph Dam Stands Nationally
Aridity defines the water calendar: about 11 inches in a normal year lands this among the driest tenth of ranked stations.
Daily temperature swings run wider than most of the country, peaking near 33°F between the normal high and low.
Chief Joseph Dam earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 8.5"
9.5 days with precipitation
Snow: 3.1"
6.7 days with precipitation
Snow: 0.6"
6.2 days with precipitation
5.0 days with precipitation
5.7 days with precipitation
5.3 days with precipitation
3.1 days with precipitation
2.1 days with precipitation
2.5 days with precipitation
5.4 days with precipitation
Snow: 2.2"
8.8 days with precipitation
Snow: 13.5"
11.2 days with precipitation
Chief Joseph Dam's wet season runs through the cold months
December, January and February carry 41% of the year's precipitation here, while June through August contribute 14%. That is the cool-season-dominant pattern of the West Coast and the higher inland West, where storm tracks swing south in winter and summer turns dry; the thermometer meanwhile shows a wide 46.1°F gap between its warmest and coldest month.
- Wettest month
- December, 2.0"
- Driest month
- August, 0.2"
- Wettest three months
- December, January, November (43% of the year)
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A cool-season label means the December-February share reaches 35%. Where snow falls, the monthly figures above report liquid-equivalent precipitation, so a wet winter month is not necessarily a rainy one.
Chief Joseph Dam is dry, and what does fall arrives gently
Only about 72 days a year record measurable precipitation here, 20% of the calendar, and they carry 10.8" between them. At roughly 0.15 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is December at about 11 wet days; the driest is August at about 2.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Winter brings real snow to Chief Joseph Dam
Chief Joseph Dam averages 27.9 inches of snowfall a year, with December the snowiest month on the normals, spread across roughly 17 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 27.9 inches of depth.
- Days recording measurable snow: about 17 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 26% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 11
50% probability date
Last Spring Freeze
April 26
50% probability date
Growing Season
168 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,874
Higher = more heating needed
Cooling Degree Days
794
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside WA closest to Chief Joseph Dam on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (51°F here).
- Deseret, UT 51°F · 0.0°F off
- Elwood, IN 51°F · 0.0°F off
- Gothenburg, NE 51°F · 0.0°F off
- Hastings, NE 51°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (10.8" here), excluding temperature-peer places.
- Joplin, MT 10.8" · 0.0" off
- Paul, ID 10.8" · 0.0" off
- Boulder, MT 10.8" · 0.0" off
- Twin Falls, ID 10.8" · 0.0" off
Snow and freeze rhythm
When cold and snow define Chief Joseph Dam
heating led · dry · mid swing
Chief Joseph Dam's energy balance leans toward cold weather: 5,874 annual heating degree days against 794 for cooling. Its 46.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
Chief Joseph Dam's frost-free season lasts about 168 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Chief Joseph Dam coldest normal
January
The monthly mean of 29°F (-2°C) sits near freezing, so cold nights and above-freezing afternoons share the same month.
-
2. Chief Joseph Dam typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Chief Joseph Dam snow peak
December
Chief Joseph Dam averages 27.9 inches of snow a year, with December the snowiest month on the normals.
Questions about Chief Joseph Dam's climate
How much snow does Chief Joseph Dam get? ▼
How many days above 90°F does Chief Joseph Dam get? ▼
How much energy does heating and cooling require in Chief Joseph Dam? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Chief Joseph Dam's primary station: CHIEF JOSEPH DAM (USC00451400). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Chief Joseph Dam; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Chief Joseph Dam comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.