Owyhee Dam, Oregon climate: Climate normals at a NOAA weather station
Owyhee Dam's normal year runs from 21°F January nights to 95°F July afternoons, with 8.8 inches of precipitation and 6 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.7°C, January lows of −6°C, July highs of 35°C, 223 mm of precipitation a year.
- NOAA stationOwyhee Dam
- Station IDUSC00356405
- Location43.65°N 117.25°W
- Elevation2,400 ft (732 m)
On October 23, the normal high in Owyhee Dam is 64°F and the normal low 33°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Owyhee Dam.
- Jan 40° 21°
- Feb 47° 24°
- Mar 57° 30°
- Apr 65° 35°
- May 75° 42°
- Jun 84° 48°
- Jul 95° 55°
- Aug 93° 53°
- Sep 83° 45°
- Oct 68° 36°
- Nov 50° 26°
- Dec 40° 21°
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 Owyhee Dam each month?
July is the warmest month, with normal highs of 95°F; January the coldest, with normal lows of 21°F. The most precipitation falls in May (1.14 in), the least in August (0.21 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 21°F | 30.5°F | 1.06 | 2.1 | 9 | <1 | 28 | 9 h 20 min |
| February | 47°F | 24°F | 35.7°F | 0.71 | 0.6 | 7 | <1 | 23 | 10 h 30 min |
| March | 57°F | 30°F | 43.5°F | 0.77 | 0.1 | 8 | <1 | 17 | 11 h 50 min |
| April | 65°F | 35°F | 49.6°F | 0.84 | 0.0 | 8 | <1 | 8 | 13 h 20 min |
| May | 75°F | 42°F | 58.4°F | 1.14 | 0.0 | 9 | 2 | 2 | 14 h 40 min |
| June | 84°F | 48°F | 65.5°F | 0.85 | 0.0 | 5 | 9 | <1 | 15 h 20 min |
| July | 95°F | 55°F | 74.7°F | 0.39 | 0.0 | 3 | 25 | <1 | 15 h 10 min |
| August | 93°F | 53°F | 73.2°F | 0.21 | 0.0 | 2 | 23 | <1 | 14 h |
| September | 83°F | 45°F | 63.8°F | 0.40 | 0.0 | 3 | 8 | <1 | 12 h 30 min |
| October | 68°F | 36°F | 51.5°F | 0.54 | 0.0 | 5 | <1 | 8 | 11 h 10 min |
| November | 50°F | 26°F | 38.3°F | 0.77 | 0.1 | 8 | <1 | 21 | 9 h 40 min |
| December | 40°F | 21°F | 30.8°F | 1.09 | 3.1 | 10 | <1 | 27 | 9 h |
| Year (annual) | 66°F | 36°F | 51.3°F | 8.77 | 6.0 | 77 | 66 | 133 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −0.8°C | 27 mm | 5 cm |
| February | 8°C | −4°C | 2.1°C | 18 mm | 2 cm |
| March | 14°C | −1°C | 6.4°C | 20 mm | 0 cm |
| April | 18°C | 1°C | 9.8°C | 21 mm | 0 cm |
| May | 24°C | 6°C | 14.7°C | 29 mm | 0 cm |
| June | 29°C | 9°C | 18.6°C | 22 mm | 0 cm |
| July | 35°C | 13°C | 23.7°C | 10 mm | 0 cm |
| August | 34°C | 12°C | 22.9°C | 5 mm | 0 cm |
| September | 28°C | 7°C | 17.7°C | 10 mm | 0 cm |
| October | 20°C | 2°C | 10.8°C | 14 mm | 0 cm |
| November | 10°C | −3°C | 3.5°C | 20 mm | 0 cm |
| December | 5°C | −6°C | −0.7°C | 28 mm | 8 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00356405; 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 Owyhee Dam?
Normal highs sit between 65°F and 85°F in May, June, September and October. Of those, September has the fewest days with rain (3).
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 USC00356405.
When is the last frost at Owyhee Dam?
In Owyhee Dam, the last spring frost (32°F) comes after May 7 in half of years and after May 27 in one year in ten; the first autumn frost comes before October 5 in half of years and before September 19 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
- May 71 year in 10 after May 27; 9 in 10 after April 23
- First autumn frost, half of years before
- October 51 year in 10 before September 19; 9 in 10 before October 20
NOAA puts the median frost-free season at 150 days, and the season without a hard freeze (28°F) at 179 days.
A hard freeze (28°F) comes after April 21 in half of springs and before October 18 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Owyhee Dam in zone 7a in ZIP code 97913, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 7a: the coldest night of a typical year reaches 4°F (28 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 USC00356405; 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 at Owyhee Dam?
In a normal year in Owyhee Dam, 66 days a year reach 90°F (16 of them 100°F or more), 133 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 66a normal year
- Days at 100°F or more
- 16a normal year
- Nights at 32°F or colder
- 133a normal year
- Days that stay below freezing
- 13high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
- Days with 1 inch of snow or more
- 2a normal year
The highest temperature in this station's record (since 1935) is 112°F, on July 14, 2002; the lowest is −22°F, on January 22, 1962.
The wettest calendar year on that record is 1983, with 17.36 in; the snowiest season is 1955–56, with 28.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00356405; records: ACIS (NOAA Regional Climate Centers), station USC00356405. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Owyhee Dam?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds at Owyhee Dam, 4.5 kWh per square metre a day. July is the sunniest month (92%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.6 |
| February | 68% | 2.6 |
| March | 72% | 4.0 |
| April | 77% | 5.5 |
| May | 79% | 6.6 |
| June | 85% | 7.5 |
| July | 92% | 7.7 |
| August | 91% | 6.7 |
| September | 88% | 5.2 |
| October | 82% | 3.5 |
| November | 72% | 2.1 |
| December | 58% | 1.3 |
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 Owyhee Dam record?
A normal year at Owyhee Dam brings 5,745 heating degree days, 7% more than the median U.S. place (5,373), and 775 cooling degree days, 15% 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 2,863 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,069 | 0 |
| February | 820 | 0 |
| March | 668 | 0 |
| April | 461 | 1 |
| May | 231 | 26 |
| June | 81 | 97 |
| July | 8 | 307 |
| August | 12 | 266 |
| September | 109 | 73 |
| October | 422 | 5 |
| November | 802 | 0 |
| December | 1,060 | 0 |
| Year (annual) | 5,745 | 775 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00356405. 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.
Have recent years at Owyhee Dam been warmer than normal?
2023 averaged 52.5°F, 1.2°F above the 1991-2020 normal of 51.3°F. 3 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 54.8°F | +3.5°F | 6.63 | 10.2 |
| 2022 | 51.7°F | +0.4°F | 9.63 | 17.6 |
| 2023 | 52.5°F | +1.2°F | 9.68 | 5.0 |
Over 77 complete years from 1938 to 2023, the station's annual mean temperature rose at a fitted 1.7°F per century (+0.09°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00356405; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Owyhee Dam's climate compare?
Owyhee Dam is warmer than 45 of the 105 places with their own NOAA record in Oregon, and wetter than 3. Across the 7,247 U.S. stations with normals, its annual mean of 51.3°F is warmer than 46%.
In the Köppen classification computed from these normals, Owyhee Dam is BSk: cold semi-arid steppe. 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.
Questions about Owyhee Dam's climate
What is the coldest month at Owyhee Dam?
January, with a normal high of 40°F and a normal low of 21°F. The warmest is July (95°F by day, 55°F at night).
Does it snow at Owyhee Dam?
Yes: 6 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in December (3.1 inches).
What is the rainiest month at Owyhee Dam?
May, with 1.14 in of precipitation in a normal year; the driest is August with 0.21 in.
What plant hardiness zone is Owyhee Dam in?
The USDA's 2023 map puts Owyhee Dam in zone 7a in ZIP code 97913, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 4°F (28 years, 1991-2020): zone 7a.
How late can frost come at Owyhee Dam?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 27. Waiting until May 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Homedale, ID17 miles from this station, 51.8°F a year
- Parma, ID19 miles from this station, 51.5°F a year
- Nyssa, OR21 miles from this station, 51.8°F a year
- Rockville (5 mi N), OR21 miles from this station, 48.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made