Bonneville Dam, OR Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Bonneville Dam's primary NOAA station, BONNEVILLE DAM.
The climate verdict for Bonneville Dam
Water is the standout signal in Bonneville Dam, Oregon: 80.2 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 53°F. At 52/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 24% of scores.
- 53°F
- yearly average temperature, NOAA normal
- 52/100
- comfort score, above 24% of station-mapped location scores
- 80.2"
- annual precipitation · 10" snow
- 258 days
- frost-free days per growing season
Bonneville Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00350897 · Bonneville Dam, OR 53°F mean · 80.2" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-WET · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 53°F
- RANK-MID #3,568
- PHOTO-FINISH ≈ Cataloochee
- PRCP-WET 80.2"
- SWING-MID 30°F
- COMF-LOW 52/100
- LOAD-HEAT 4,784 HDD
- STN-1 USC00350897
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Cataloochee, NC ( -0.1 °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 OR station list.
- Bonneville Dam (this station) 53°F
- Cold Cascade Locks, OR 53°F
- Hot Rex, OR 53°F
- Near Cataloochee, NC 53°F
- Near Mtn Park, NM 53°F
Climate Living Index · Bonneville Dam
Bonneville Dam: 63/100 · grade C
Bonneville 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 Bonneville Dam, not an official NOAA rating. Rankings still use Comfort Score 52/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Frost-free season | 258 days/year | 91/100 · A |
| Snowfall burden | 10.3 inches/year | 63/100 · C |
| Annual temperature balance | 52.8°F · 14.7° from 67.5°F | 52/100 · D |
| Precipitation balance | 80.2 in · 45.2 from 35 in | 0/100 · F |
Bonneville Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Bonneville Dam is a temperate Köppen climate: Csb
Coldest-month mean 38.5°F and warmest-month mean 68.6°F place this station in temperate, dry-summer, warm summer climates (Csb). Class Csb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, dry-summer, warm summer.
- Köppen code
- Csb
- Group
- Temperate
- Warmest month
- 68.6°F
- Coldest month
- 38.5°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 Bonneville Dam sits across the climate record
Three NOAA fields for Bonneville Dam's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 52nd percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Top 1% wettest
- Bonneville Dam's annual total ranks in the wetter third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 90%
- Warmest-to-coldest month gap for Bonneville Dam is compact versus 6,861 complete station-years.
How Bonneville Dam compares across U.S. station-mapped locations
Bonneville Dam's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
52 24th percentile score exceeds 24% 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%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). This entry sits in this band.
- 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
Bonneville Dam's measured station temperature trend
MethodologyAcross 71 complete annual observations from 1940 to 2025, BONNEVILLE DAM warmed at a fitted rate of 0.19°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Bonneville Dam primary station fitted change +0.19 °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 | 43°F (6°C) | 34°F (1°C) | 39°F (4°C) | 11.3" | 3.5" | 9.5 | 0.0 |
| February | 47°F (8°C) | 36°F (2°C) | 41°F (5°C) | 8.7" | 3.4" | 7.2 | 0.0 |
| March | 53°F (12°C) | 38°F (3°C) | 46°F (8°C) | 9.1" | 0.3" | 3.5 | 0.0 |
| April | 59°F (15°C) | 42°F (6°C) | 51°F (10°C) | 6.5" | 0.0" | 0.3 | 0.0 |
| May | 67°F (19°C) | 48°F (9°C) | 57°F (14°C) | 4.1" | 0.0" | 0.0 | 0.2 |
| June | 72°F (22°C) | 52°F (11°C) | 62°F (17°C) | 3.2" | 0.0" | 0.0 | 1.2 |
| July | 79°F (26°C) | 57°F (14°C) | 68°F (20°C) | 0.6" | 0.0" | 0.0 | 3.8 |
| August | 80°F (27°C) | 58°F (14°C) | 69°F (20°C) | 0.9" | 0.0" | 0.0 | 3.9 |
| September | 74°F (23°C) | 53°F (12°C) | 64°F (18°C) | 2.6" | 0.0" | 0.0 | 1.4 |
| October | 62°F (17°C) | 47°F (8°C) | 55°F (13°C) | 7.3" | 0.0" | 0.3 | 0.0 |
| November | 50°F (10°C) | 40°F (4°C) | 45°F (7°C) | 12.5" | 0.2" | 3.1 | 0.0 |
| December | 42°F (6°C) | 35°F (2°C) | 39°F (4°C) | 13.4" | 2.9" | 9.0 | 0.0 |
The year, day by day
The calendar barely moves in Bonneville Dam: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 34°F near January 1 and 81°F near July 30.
No freezing date
Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 34°F around January 1.
Where the wet dates fall
The likeliest wet date is December 19, when 72% of years recorded at least a hundredth of an inch. The driest is July 31 at 11%. Summed across the calendar, that is about 179 wet dates a year.
The widest day
August 28 carries the biggest normal gap between afternoon and dawn, 22°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Bonneville Dam.
Where Bonneville Dam Stands Nationally
This is one of the wettest normals climates ranked: about 80 inches of precipitation in a normal year, a total fewer than one station in ten surpasses.
Days and nights track unusually close together; the widest normal swing, about 22°F, is narrower than most stations record.
Bonneville 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: 3.5"
21.6 days with precipitation
Snow: 3.4"
18.2 days with precipitation
Snow: 0.3"
20.2 days with precipitation
18.8 days with precipitation
14.5 days with precipitation
11.2 days with precipitation
4.2 days with precipitation
3.7 days with precipitation
7.8 days with precipitation
15.4 days with precipitation
Snow: 0.2"
21.1 days with precipitation
Snow: 2.9"
22.1 days with precipitation
Bonneville Dam's wet season runs through the cold months
December, January and February carry 42% of the year's precipitation here, while June through August contribute 6%. 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 30.1°F seasonal spread.
- Wettest month
- December, 13.4"
- Driest month
- July, 0.6"
- Wettest three months
- December, November, January (46% 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.
When it rains in Bonneville Dam, it arrives in quantity
80.2" of precipitation falls across only about 179 wet days here, averaging 0.45 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 179 a year, 49% of all days
- Average depth per wet day
- 0.45 inches
- Most wet days
- December, about 22
- Fewest wet days
- August, about 4
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Snow reaches Bonneville Dam, but rarely amounts to much
The normals record 10.3 inches of snow a year here, most likely in January. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation; about 5 days a year record any measurable snow at all.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
November 27
50% probability date
Last Spring Freeze
March 14
50% probability date
Growing Season
258 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,784
Higher = more heating needed
Cooling Degree Days
356
Higher = more cooling needed
Warmest Month
August
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside OR closest to Bonneville 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 (53°F here).
- Alderson, WV 53°F · 0.0°F off
- Anacortes, WA 53°F · 0.0°F off
- Bentley, IL 53°F · 0.0°F off
- Biglerville, PA 53°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (80.2" here), excluding temperature-peer places.
- Klamath, CA 78.9" · 1.3" off
- Valdez, AK 82.1" · 1.9" off
- Kodiak, AK 78.3" · 1.9" off
- Point Baker, AK 82.3" · 2.1" off
Data-derived climate profile
How Bonneville Dam's climate pattern fits together
heating led · wet · mid swing
Bonneville Dam's energy balance leans toward cold weather: 4,784 annual heating degree days against 356 for cooling. Its 30.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
The frost-free window extends for about 258 days. That is a long calendar measure, but it is not a forecast and does not combine heat, rainfall, soil, or local elevation into a planting recommendation.
August and January mark the typical warm and cold ends of the calendar in Bonneville Dam's middle-range seasonal profile. The measured spread is 30.1°F. The annual average is 53°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Alongside its heating load, Bonneville Dam carries 80.2 inches of precipitation in a normal year, inside PlainClimate's wet range. Annual snowfall totals 10.3 inches. That distinction matters because a wet annual total can arrive as rain, snow, or a mixture at different times.
These labels group NOAA 1991-2020 normals from Bonneville Dam's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Bonneville Dam, not an official NOAA class or a year-ahead forecast.
Questions about Bonneville Dam's climate
How much rain does Bonneville Dam get? ▼
How much energy does heating and cooling require in Bonneville Dam? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Bonneville Dam's primary station: BONNEVILLE DAM (USC00350897). 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 Bonneville 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 Bonneville 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.