Forest Grove, OR Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Forest Grove's primary NOAA station, FOREST GROVE.
The climate verdict for Forest Grove
Water is the standout signal in Forest Grove, Oregon: 46.7 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 52°F. Its climate comfort score of 73/100 (good) lands mid-pack nationally, exceeding 66% of station-mapped location scores.
- 52°F
- average temperature, NOAA 1991-2020 normal
- 73/100
- comfort score, above 66% of station-mapped location scores
- 46.7"
- annual precipitation · 3" snow
- 193 days
- frost-free days per growing season
Forest Grove: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00352997 · Forest Grove, OR 52°F mean · 46.7" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 52°F
- RANK-MID #3,431
- PHOTO-FINISH ≈ Ashland
- PRCP-MID 46.7"
- SWING-NARROW 30°F
- COMF-MID 73/100
- LOAD-HEAT 5,027 HDD
- STN-1 USC00352997
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Ashland, OR (+ 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.
- Forest Grove (this station) 52°F
- Cold Roan Mtn, TN 52°F
- Hot Callahan, CA 52°F
- Near Ashland, OR 52°F
- Near Celo, NC 52°F
Climate Living Index · Forest Grove
Forest Grove: 70/100 · grade B
Forest Grove publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Forest Grove, 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 |
| Snowfall burden | 2.7 inches/year | 74/100 · B |
| Frost-free season | 193 days/year | 59/100 · C |
| Precipitation balance | 46.7 in · 11.7 from 35 in | 59/100 · C |
| Annual temperature balance | 52.1°F · 15.4° from 67.5°F | 50/100 · D |
Forest Grove · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Forest Grove is a temperate Köppen climate: Csb
Coldest-month mean 38.4°F and warmest-month mean 67.9°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
- 67.9°F
- Coldest month
- 38.4°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 Forest Grove sits across the climate record
Three NOAA fields for Forest Grove's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 50th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Top 28% wettest
- Forest Grove's annual total ranks in the wetter third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 91%
- Warmest-to-coldest month gap for Forest Grove is compact versus 6,861 complete station-years.
How Forest Grove compares across U.S. station-mapped locations
Forest Grove'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
Forest Grove's measured station temperature trend
MethodologyAcross 82 complete annual observations from 1892 to 2025, FOREST GROVE warmed at a fitted rate of 0.12°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Forest Grove primary station fitted change +0.12 °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 | 45°F (7°C) | 33°F (0°C) | 39°F (4°C) | 7.2" | 0.6" | 13.3 | 0.0 |
| February | 49°F (10°C) | 33°F (1°C) | 41°F (5°C) | 5.8" | 0.6" | 12.1 | 0.0 |
| March | 55°F (13°C) | 36°F (2°C) | 45°F (7°C) | 5.0" | 0.0" | 8.1 | 0.0 |
| April | 60°F (16°C) | 39°F (4°C) | 50°F (10°C) | 3.3" | 0.0" | 3.0 | 0.0 |
| May | 68°F (20°C) | 45°F (7°C) | 57°F (14°C) | 2.2" | 0.0" | 0.3 | 1.1 |
| June | 73°F (23°C) | 50°F (10°C) | 61°F (16°C) | 1.4" | 0.0" | 0.0 | 2.3 |
| July | 81°F (27°C) | 54°F (12°C) | 68°F (20°C) | 0.3" | 0.0" | 0.0 | 7.5 |
| August | 82°F (28°C) | 54°F (12°C) | 68°F (20°C) | 0.5" | 0.0" | 0.0 | 8.4 |
| September | 76°F (24°C) | 49°F (9°C) | 62°F (17°C) | 1.3" | 0.0" | 0.0 | 3.4 |
| October | 63°F (17°C) | 42°F (5°C) | 52°F (11°C) | 3.7" | 0.2" | 2.3 | 0.1 |
| November | 51°F (11°C) | 36°F (2°C) | 44°F (6°C) | 7.2" | 0.0" | 8.8 | 0.0 |
| December | 44°F (7°C) | 33°F (0°C) | 38°F (4°C) | 8.7" | 1.3" | 13.2 | 0.0 |
The year, day by day
The calendar barely moves in Forest Grove: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 32°F near December 24 and 84°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 32°F around December 24.
Where the wet dates fall
The likeliest wet date is November 29, when 64% of years recorded at least a hundredth of an inch. The driest is July 28 at 7%. Summed across the calendar, that is about 147 wet dates a year.
The widest day
July 30 carries the biggest normal gap between afternoon and dawn, 29°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Forest Grove.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 0.6"
18.6 days with precipitation
Snow: 0.6"
15.0 days with precipitation
17.2 days with precipitation
15.9 days with precipitation
11.2 days with precipitation
8.1 days with precipitation
2.4 days with precipitation
2.9 days with precipitation
5.4 days with precipitation
Snow: 0.2"
11.4 days with precipitation
18.6 days with precipitation
Snow: 1.3"
19.4 days with precipitation
Forest Grove's wet season runs through the cold months
December, January and February carry 46% of the year's precipitation here, while June through August contribute 5%. 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 29.5°F seasonal spread.
- Wettest month
- December, 8.7"
- Driest month
- July, 0.3"
- Wettest three months
- December, November, January (50% 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 Forest Grove's precipitation splits across the calendar
About 146 days a year record measurable precipitation here, carrying 46.7" between them, or roughly 0.32 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.
Snow reaches Forest Grove, but rarely amounts to much
The normals record 2.7 inches of snow a year here, most likely in December. 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 1 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
October 26
50% probability date
Last Spring Freeze
April 16
50% probability date
Growing Season
193 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,027
Higher = more heating needed
Cooling Degree Days
347
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside OR closest to Forest Grove 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 (52°F here).
- Canon City, CO 52°F · 0.0°F off
- Donora, PA 52°F · 0.0°F off
- Dyer, NV 52°F · 0.0°F off
- Everett, WA 52°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (46.7" here), excluding temperature-peer places.
- Laurens, SC 46.7" · 0.0" off
- Montrose, PA 46.7" · 0.0" off
- Durham, NC 46.7" · 0.0" off
- Monticello, GA 46.7" · 0.0" off
Data-derived climate profile
How Forest Grove's climate pattern fits together
heating led · wet · low swing
Heating is the larger measured load in Forest Grove, at 5,027 degree days versus 347 for cooling. Unlike a strongly continental record, however, its 29.5°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
Forest Grove's frost-free season lasts about 193 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
Forest Grove's 29.5°F seasonal spread is compact even though precipitation is abundant. August and December mark the typical warm and cold ends of the calendar. The annual average is 52°F. Temperature is relatively steady; the monthly rows show how rain and snow observations vary across the calendar.
Alongside its heating load, Forest Grove carries 46.7 inches of precipitation in a normal year, inside PlainClimate's wet range. Annual snowfall totals 2.7 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 Forest Grove'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 Forest Grove, not an official NOAA class or a year-ahead forecast.
Questions about Forest Grove's climate
How much rain does Forest Grove get? ▼
How much energy does heating and cooling require in Forest Grove? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Forest Grove's primary station: FOREST GROVE (USC00352997). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 4126200). Match rule for Forest Grove: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Forest Grove 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.