Portland Troutdale, OR 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 Portland Troutdale's primary NOAA station, PORTLAND TROUTDALE AP.
The climate verdict for Portland Troutdale
A compact 28°F seasonal swing gives Portland Troutdale, Oregon a steadier-than-extreme annual shape. NOAA reports an annual average of 55°F. Its climate comfort score of 73/100 (good) lands mid-pack nationally, exceeding 66% of station-mapped location scores.
- 55°F
- annual average temperature (NOAA normal)
- 73/100
- comfort score, above 66% of station-mapped location scores
- 40.7"
- precipitation, annual total
- 249 days
- growing season, frost-free days
Portland Troutdale: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00024242 · Portland Troutdale, OR 55°F mean · 40.7" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 55°F
- RANK-MID #4,048
- PHOTO-FINISH ≈ Portland Kgw-tv
- PRCP-MID 40.7"
- SWING-NARROW 28°F
- COMF-MID 73/100
- LOAD-HEAT 4,155 HDD
- STN-1 USW00024242
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Portland Kgw-tv, OR (+ 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 OR station list.
- Portland Troutd… (this station) 55°F
- Hot Winchester, OR 55°F
- Near Portland Kgw-tv, OR 55°F
- Near Aurora State, OR 55°F
- Near Lebanon, OR 55°F
Climate Living Index · Portland Troutdale
Portland Troutdale: 80/100 · grade B
Portland Troutdale publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Portland Troutdale, not an official NOAA rating. Rankings still use Comfort Score 73/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Frost-free season | 249 days/year | 88/100 · A |
| Precipitation balance | 40.7 in · 5.7 from 35 in | 80/100 · B |
| Annual temperature balance | 54.7°F · 12.8° from 67.5°F | 58/100 · C |
Portland Troutdale · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Portland Troutdale is a temperate Köppen climate: Csb
Coldest-month mean 41.6°F and warmest-month mean 69.6°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
- 69.6°F
- Coldest month
- 41.6°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 Portland Troutdale sits across the climate record
Three NOAA fields for Portland Troutdale's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 59th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 59th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 93%
- Warmest-to-coldest month gap for Portland Troutdale is compact versus 6,861 complete station-years.
How Portland Troutdale compares across U.S. station-mapped locations
Portland Troutdale's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
73 Top 34% score exceeds 66% 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%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). This entry sits in this band.
- 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
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 47°F (8°C) | 37°F (3°C) | 42°F (6°C) | 5.0" | 7.3 | 0.0 |
| February | 51°F (11°C) | 38°F (3°C) | 44°F (7°C) | 3.7" | 6.3 | 0.0 |
| March | 57°F (14°C) | 40°F (4°C) | 48°F (9°C) | 4.4" | 3.7 | 0.0 |
| April | 62°F (17°C) | 43°F (6°C) | 53°F (11°C) | 3.6" | 0.9 | 0.0 |
| May | 69°F (21°C) | 49°F (9°C) | 59°F (15°C) | 2.9" | 0.0 | 0.3 |
| June | 74°F (23°C) | 53°F (12°C) | 64°F (18°C) | 2.1" | 0.0 | 2.3 |
| July | 82°F (28°C) | 57°F (14°C) | 69°F (21°C) | 0.6" | 0.0 | 5.7 |
| August | 82°F (28°C) | 57°F (14°C) | 70°F (21°C) | 0.6" | 0.0 | 6.2 |
| September | 76°F (25°C) | 52°F (11°C) | 64°F (18°C) | 1.8" | 0.0 | 1.9 |
| October | 64°F (18°C) | 46°F (8°C) | 55°F (13°C) | 4.0" | 0.5 | 0.0 |
| November | 53°F (11°C) | 42°F (5°C) | 47°F (8°C) | 5.8" | 3.0 | 0.0 |
| December | 46°F (8°C) | 37°F (3°C) | 42°F (5°C) | 6.2" | 6.5 | 0.0 |
The year, day by day
The calendar barely moves in Portland Troutdale: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 37°F near December 23 and 83°F near July 28.
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 37°F around December 23.
Where the wet dates fall
The likeliest wet date is December 19, when 61% of years recorded at least a hundredth of an inch. The driest is July 29 at 10%. Summed across the calendar, that is about 160 wet dates a year.
The widest day
August 24 carries the biggest normal gap between afternoon and dawn, 26°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Portland Troutdale.
Monthly Precipitation
Average monthly rainfall
18.3 days with precipitation
15.9 days with precipitation
18.6 days with precipitation
16.7 days with precipitation
13.6 days with precipitation
9.8 days with precipitation
3.6 days with precipitation
3.8 days with precipitation
7.0 days with precipitation
15.3 days with precipitation
18.3 days with precipitation
18.5 days with precipitation
Portland Troutdale's wet season runs through the cold months
December, January and February carry 37% of the year's precipitation here, while June through August contribute 8%. 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 an unusually narrow 28°F seasonal spread.
- Wettest month
- December, 6.2"
- Driest month
- July, 0.6"
- Wettest three months
- December, November, January (42% 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.
How Portland Troutdale's precipitation splits across the calendar
About 159 days a year record measurable precipitation here, carrying 40.7" between them, or roughly 0.26 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Frost Dates & Growing Season
First Fall Freeze
November 20
50% probability date
Last Spring Freeze
March 16
50% probability date
Growing Season
249 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,155
Higher = more heating needed
Cooling Degree Days
427
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside OR closest to Portland Troutdale 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 (55°F here).
- Abingdon, VA 55°F · 0.0°F off
- Cottonwood Falls, KS 55°F · 0.0°F off
- Cranford, NJ 55°F · 0.0°F off
- Ellsworth, KS 55°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (40.7" here), excluding temperature-peer places.
- Alderson, WV 40.7" · 0.0" off
- Olean, NY 40.7" · 0.0" off
- Albany, NY 40.7" · 0.0" off
- Buffalo, NY 40.7" · 0.0" off
Data-derived climate profile
How Portland Troutdale's climate pattern fits together
heating led · moderate · low swing
Heating is the larger measured load in Portland Troutdale, at 4,155 degree days versus 427 for cooling. Unlike a strongly continental record, however, its 28.0°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
The frost-free window extends for about 249 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.
Temperature varies within a narrow 28.0°F band across the normal year. August and December mark the typical warm and cold ends of the calendar. The annual average is 55°F. Monthly rows still matter, but they refine a steady profile rather than reveal two climatic extremes.
Portland Troutdale's 40.7 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Snowfall is not added to the interpretation because its annual value is missing. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Portland Troutdale'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 Portland Troutdale, not an official NOAA class or a year-ahead forecast.
Questions about Portland Troutdale's climate
How much rain does Portland Troutdale get? ▼
How much energy does heating and cooling require in Portland Troutdale? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Portland Troutdale's primary station: PORTLAND TROUTDALE AP (USW00024242). 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 Portland Troutdale; 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 Portland Troutdale 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.