Illahe, Oregon climate: Climate normals at a NOAA weather station
Illahe's normal year runs from 36°F December nights to 91°F August afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.3°C, December lows of 2°C, August highs of 33°C.
- NOAA stationIllahe
- Station IDUSC00354133
- Location42.63°N 124.06°W
- Elevation348 ft (106 m)
On October 23, the normal high in Illahe is 64°F and the normal low 43°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Illahe.
- Jan 51° 37°
- Feb 54° 38°
- Mar 59° 39°
- Apr 65° 40°
- May 75° 43°
- Jun 81° 49°
- Jul 90° 52°
- Aug 91° 52°
- Sep 86° 48°
- Oct 69° 44°
- Nov 55° 40°
- Dec 51° 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 at Illahe each month?
August is the warmest month, with normal highs of 91°F; December the coldest, with normal lows of 36°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 51°F | 37°F | 44.2°F | – | <1 | 5 | 9 h 20 min |
| February | 54°F | 38°F | 45.9°F | – | <1 | 4 | 10 h 30 min |
| March | 59°F | 39°F | 49.0°F | – | <1 | 2 | 11 h 50 min |
| April | 65°F | 40°F | 52.3°F | – | <1 | <1 | 13 h 20 min |
| May | 75°F | 43°F | 59.1°F | – | 2 | <1 | 14 h 40 min |
| June | 81°F | 49°F | 64.7°F | – | 4 | <1 | 15 h 20 min |
| July | 90°F | 52°F | 71.0°F | – | 15 | <1 | 15 h |
| August | 91°F | 52°F | 71.5°F | – | 17 | <1 | 14 h |
| September | 86°F | 48°F | 67.0°F | – | 11 | <1 | 12 h 30 min |
| October | 69°F | 44°F | 56.3°F | – | <1 | 1 | 11 h 10 min |
| November | 55°F | 40°F | 47.4°F | – | <1 | 3 | 9 h 50 min |
| December | 51°F | 36°F | 43.1°F | – | <1 | 5 | 9 h |
| Year (annual) | 69°F | 43°F | 55.9°F | – | 49 | 19 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 11°C | 3°C | 6.8°C |
| February | 12°C | 3°C | 7.7°C |
| March | 15°C | 4°C | 9.4°C |
| April | 18°C | 4°C | 11.3°C |
| May | 24°C | 6°C | 15.1°C |
| June | 27°C | 9°C | 18.2°C |
| July | 32°C | 11°C | 21.7°C |
| August | 33°C | 11°C | 21.9°C |
| September | 30°C | 9°C | 19.4°C |
| October | 21°C | 6°C | 13.5°C |
| November | 13°C | 4°C | 8.6°C |
| December | 10°C | 2°C | 6.2°C |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00354133; 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.
Which months are mildest at Illahe?
Normal highs sit between 65°F and 85°F in May, June and October.
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 USC00354133.
When is the last frost at Illahe?
In Illahe, the last spring frost (32°F) comes after March 30 in half of years and after May 2 in one year in ten; the first autumn frost comes before November 17 in half of years and before October 20 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 301 year in 10 after May 2; 9 in 10 after February 20
- First autumn frost, half of years before
- November 171 year in 10 before October 20; 9 in 10 before December 15
NOAA puts the median frost-free season at 233 days, and the season without a hard freeze (28°F) at 315 days.
A hard freeze (28°F) comes after February 1 in half of springs and before December 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Illahe in zone 9a in ZIP code 97406, the nearest ZIP area.
Frost dates for every NOAA station in Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00354133; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 at Illahe?
In a normal year in Illahe, 49 days a year reach 90°F (8 of them 100°F or more) and 19 nights fall to 32°F or colder.
- Days at 90°F or more
- 49a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 19a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
The highest temperature in this station's record (since 1938) is 112°F, on July 19, 1946; the lowest is 6°F, on December 10, 1972.
The wettest calendar year on that record is 1996, with 128.21 in; the snowiest season is 1968–69, with 90.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00354133; records: ACIS (NOAA Regional Climate Centers), station USC00354133. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Illahe?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds at Illahe, 4.2 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.7 |
| February | 65% | 2.5 |
| March | 66% | 3.6 |
| April | 71% | 5.0 |
| May | 77% | 6.3 |
| June | 81% | 7.0 |
| July | 87% | 7.3 |
| August | 85% | 6.2 |
| September | 82% | 4.8 |
| October | 75% | 3.2 |
| November | 65% | 1.9 |
| December | 60% | 1.4 |
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 many heating and cooling degree days does Illahe record?
A normal year at Illahe brings 3,883 heating degree days, 28% fewer than the median U.S. place (5,373), and 604 cooling degree days, 33% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,984 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 646 | 0 |
| February | 535 | 0 |
| March | 496 | 0 |
| April | 380 | 1 |
| May | 210 | 27 |
| June | 69 | 61 |
| July | 9 | 195 |
| August | 10 | 210 |
| September | 44 | 104 |
| October | 278 | 6 |
| November | 528 | 0 |
| December | 679 | 0 |
| Year (annual) | 3,883 | 604 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00354133. 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.
How does Illahe's climate compare?
Illahe is warmer than 102 of the 105 places with their own NOAA record in Oregon. Across the 7,247 U.S. stations with normals, its annual mean of 55.9°F is warmer than 63%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Questions about Illahe's climate
What is the coldest month at Illahe?
December, with a normal high of 51°F and a normal low of 36°F. The warmest is August (91°F by day, 52°F at night).
What plant hardiness zone is Illahe in?
The USDA's 2023 map puts Illahe in zone 9a in ZIP code 97406, the nearest ZIP area.
How late can frost come at Illahe?
In half of years the last 32°F night comes after March 30; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Powers, OR18 miles from this station, 54.9°F a year
- Port Orford, OR24 miles from this station, 53.4°F a year
- Gold Beach, OR24 miles from this station, 54.0°F a year
- Langlois, OR29 miles from this station, 52.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made