Troutdale, Oregon climate: Normal weather by month, frost dates and records
Troutdale's normal year runs from 35°F January nights to 81°F August afternoons, with 48.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.9°C, January lows of 2°C, August highs of 27°C, 1,229 mm of precipitation a year.
- NOAA stationTroutdale
- Station IDUSC00358634
- Location45.55°N 122.39°W
- Elevation33 ft (10 m)
- From the center1 miles
- Population15,749
On October 23, the normal high in Troutdale is 59°F and the normal low 44°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Troutdale.
- Jan 44° 35°
- Feb 49° 37°
- Mar 55° 39°
- Apr 61° 42°
- May 68° 48°
- Jun 73° 52°
- Jul 81° 56°
- Aug 81° 56°
- Sep 75° 51°
- Oct 63° 46°
- Nov 51° 40°
- Dec 45° 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 Troutdale each month?
August is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 35°F. The most precipitation falls in November (7.47 in), the least in July (0.64 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 44°F | 35°F | 39.8°F | 6.31 | – | <1 | 10 | 9 h |
| February | 49°F | 37°F | 42.5°F | 4.69 | – | <1 | 8 | 10 h 20 min |
| March | 55°F | 39°F | 46.7°F | 5.07 | – | <1 | 5 | 11 h 50 min |
| April | 61°F | 42°F | 51.2°F | 4.24 | – | <1 | 1 | 13 h 30 min |
| May | 68°F | 48°F | 57.8°F | 3.31 | – | <1 | <1 | 14 h 50 min |
| June | 73°F | 52°F | 62.4°F | 2.40 | – | 2 | <1 | 15 h 40 min |
| July | 81°F | 56°F | 68.2°F | 0.64 | – | 6 | <1 | 15 h 20 min |
| August | 81°F | 56°F | 68.4°F | 0.70 | – | 7 | <1 | 14 h 10 min |
| September | 75°F | 51°F | 63.2°F | 1.86 | – | 2 | <1 | 12 h 40 min |
| October | 63°F | 46°F | 54.3°F | 4.59 | – | <1 | 1 | 11 h |
| November | 51°F | 40°F | 45.9°F | 7.47 | – | <1 | 5 | 9 h 30 min |
| December | 45°F | 36°F | 40.2°F | 7.10 | – | <1 | 9 | 8 h 40 min |
| Year (annual) | 62°F | 45°F | 53.4°F | 48.38 | – | 18 | 40 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 7°C | 2°C | 4.3°C | 160 mm |
| February | 9°C | 3°C | 5.8°C | 119 mm |
| March | 13°C | 4°C | 8.2°C | 129 mm |
| April | 16°C | 5°C | 10.7°C | 108 mm |
| May | 20°C | 9°C | 14.3°C | 84 mm |
| June | 23°C | 11°C | 16.9°C | 61 mm |
| July | 27°C | 13°C | 20.1°C | 16 mm |
| August | 27°C | 13°C | 20.2°C | 18 mm |
| September | 24°C | 11°C | 17.3°C | 47 mm |
| October | 17°C | 8°C | 12.4°C | 117 mm |
| November | 11°C | 5°C | 7.7°C | 190 mm |
| December | 7°C | 2°C | 4.6°C | 180 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Portland Weather Office (7 miles away), gets 3 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00358634; 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 Troutdale?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
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 USC00358634.
When is the last frost in Troutdale?
In Troutdale, the last spring frost (32°F) comes after March 26 in half of years and after April 21 in one year in ten; the first autumn frost comes before November 17 in half of years and before October 26 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
- March 261 year in 10 after April 21; 9 in 10 after February 27
- First autumn frost, half of years before
- November 171 year in 10 before October 26; 9 in 10 before December 10
NOAA puts the median frost-free season at 237 days, and the season without a hard freeze (28°F) at 292 days.
A hard freeze (28°F) comes after February 22 in half of springs and before December 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Troutdale in zone 9a in ZIP code 97060. By the map's own method, the average of each year's coldest night over 1991-2020, Troutdale's NOAA station is in zone 9a: the coldest night of a typical year reaches 23°F (16 complete years).
Frost dates for every NOAA station in Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00358634; 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 Troutdale?
In a normal year in Troutdale, 18 days a year reach 90°F (2 of them 100°F or more) and 40 nights fall to 32°F or colder.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 40a normal year
- Days that stay below freezing
- 3high of 32°F or less
The highest temperature in this station's record (since 1965) is 110°F, on June 28, 2021; the lowest is 0°F, on February 4, 1989.
The wettest calendar year on that record is 1971, with 55.84 in; the snowiest season is 1979–80, with 25.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00358634; records: ACIS (NOAA Regional Climate Centers), station USC00358634. Records use complete months only; a month missing more than three days is left out.
How sunny is Troutdale?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Troutdale, 3.7 kWh per square metre a day. July is the sunniest month (83%) and December the cloudiest (52%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 54% | 1.2 |
| February | 60% | 2.1 |
| March | 59% | 3.0 |
| April | 63% | 4.3 |
| May | 68% | 5.4 |
| June | 70% | 6.0 |
| July | 83% | 6.8 |
| August | 83% | 5.8 |
| September | 78% | 4.3 |
| October | 67% | 2.6 |
| November | 56% | 1.4 |
| December | 52% | 1.0 |
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 Troutdale need?
A normal year in Troutdale brings 4,574 heating degree days, 15% fewer than the median U.S. place (5,373), and 361 cooling degree days, 60% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,453 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 781 | 0 |
| February | 630 | 0 |
| March | 566 | 0 |
| April | 415 | 1 |
| May | 239 | 16 |
| June | 116 | 40 |
| July | 26 | 126 |
| August | 23 | 130 |
| September | 98 | 46 |
| October | 336 | 3 |
| November | 575 | 0 |
| December | 770 | 0 |
| Year (annual) | 4,574 | 361 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00358634. 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 Troutdale been warmer than normal lately?
2023 averaged 54.0°F, 0.6°F above the 1991-2020 normal of 53.4°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 53.9°F | +0.5°F | – |
| 2023 | 54.0°F | +0.6°F | – |
Over 38 complete years from 1949 to 2023, the station's annual mean temperature rose at a fitted 3.5°F per century (+0.19°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00358634; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Troutdale's climate compare?
Troutdale is warmer than 77 of the other 104 places with their own NOAA record in Oregon, and wetter than 69. Across the 7,247 U.S. stations with normals, its annual mean of 53.4°F is warmer than 55%.
In the Köppen classification computed from these normals, Troutdale 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 Troutdale share this climate record?
2 places have no NOAA station with 1991-2020 normals of their 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.
- Washougal, WA17,944 people · 3 mi NE
- Fern Prairie, WA2,132 people · 6 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 Troutdale's climate
What is the coldest month in Troutdale?
January, with a normal high of 44°F and a normal low of 35°F. The warmest is August (81°F by day, 56°F at night).
Does it snow in Troutdale?
Yes. NOAA publishes no 1991-2020 snowfall normal for Troutdale's NOAA station; the nearest record that keeps one, Portland Weather Office (7 miles away), records 3 inches of snow in a normal year.
What is the rainiest month in Troutdale?
November, with 7.47 in of precipitation in a normal year; the driest is July with 0.64 in.
What plant hardiness zone is Troutdale in?
The USDA's 2023 map puts Troutdale in zone 9a in ZIP code 97060. By the same method at Troutdale's NOAA station, the coldest night of a typical year reaches 23°F (16 years, 1991-2020): zone 9a.
How late can frost come in Troutdale?
In half of years the last 32°F night comes after March 26; in one year in ten it comes after April 21. Waiting until April 21 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Portland Troutdale Airport, OR1 miles from this station, 54.7°F a year
- Skamania Fish Hatchery, WA9 miles from this station, 50.9°F a year
- Portland, OR11 miles from this station, 55.1°F a year
- Headworks Portland Water B, OR14 miles from this station, 51.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made