McNary Dam #2, Oregon climate: Climate normals at a NOAA weather station
McNary Dam #2's normal year runs from 30°F January nights to 89°F July afternoons, with 7.9 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.2°C, January lows of −1°C, July highs of 31°C, 201 mm of precipitation a year.
- NOAA stationMcNary Dam #2
- Station IDUSC00355392
- Location45.93°N 119.30°W
- Elevation361 ft (110 m)
On October 23, the normal high in McNary Dam #2 is 61°F and the normal low 42°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for McNary Dam #2.
- Jan 41° 30°
- Feb 46° 32°
- Mar 56° 35°
- Apr 63° 42°
- May 72° 48°
- Jun 79° 54°
- Jul 89° 61°
- Aug 88° 61°
- Sep 78° 53°
- Oct 64° 44°
- Nov 51° 35°
- Dec 41° 31°
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 McNary Dam #2 each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 30°F. The most precipitation falls in December (1.22 in), the least in July (0.19 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 41°F | 30°F | 35.6°F | 0.88 | 13 | <1 | 18 | 9 h |
| February | 46°F | 32°F | 38.9°F | 0.70 | 10 | <1 | 16 | 10 h 20 min |
| March | 56°F | 35°F | 45.4°F | 0.76 | 11 | <1 | 8 | 11 h 50 min |
| April | 63°F | 42°F | 52.2°F | 0.70 | 8 | <1 | 1 | 13 h 30 min |
| May | 72°F | 48°F | 60.0°F | 0.75 | 7 | <1 | <1 | 14 h 50 min |
| June | 79°F | 54°F | 66.7°F | 0.45 | 6 | 3 | <1 | 15 h 40 min |
| July | 89°F | 61°F | 74.5°F | 0.19 | 2 | 14 | <1 | 15 h 30 min |
| August | 88°F | 61°F | 74.3°F | 0.25 | 2 | 13 | <1 | 14 h 10 min |
| September | 78°F | 53°F | 65.7°F | 0.40 | 3 | 2 | <1 | 12 h 40 min |
| October | 64°F | 44°F | 54.2°F | 0.74 | 9 | <1 | 2 | 11 h |
| November | 51°F | 35°F | 42.9°F | 0.87 | 10 | <1 | 10 | 9 h 30 min |
| December | 41°F | 31°F | 36.0°F | 1.22 | 14 | <1 | 20 | 8 h 40 min |
| Year (annual) | 64°F | 44°F | 53.9°F | 7.91 | 95 | 33 | 74 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −1°C | 2.0°C | 22 mm |
| February | 8°C | 0°C | 3.8°C | 18 mm |
| March | 13°C | 2°C | 7.4°C | 19 mm |
| April | 17°C | 5°C | 11.2°C | 18 mm |
| May | 22°C | 9°C | 15.6°C | 19 mm |
| June | 26°C | 12°C | 19.3°C | 11 mm |
| July | 31°C | 16°C | 23.6°C | 5 mm |
| August | 31°C | 16°C | 23.5°C | 6 mm |
| September | 26°C | 12°C | 18.7°C | 10 mm |
| October | 18°C | 7°C | 12.3°C | 19 mm |
| November | 10°C | 2°C | 6.1°C | 22 mm |
| December | 5°C | −1°C | 2.2°C | 31 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Boardman (20 miles away), gets 4 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00355392; 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 McNary Dam #2?
Normal highs sit between 65°F and 85°F in May, June and September. 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 USC00355392.
When is the last frost at McNary Dam #2?
In McNary Dam #2, the last spring frost (32°F) comes after March 30 in half of years and after April 20 in one year in ten; the first autumn frost comes before November 4 in half of years and before October 21 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 April 20; 9 in 10 after March 12
- First autumn frost, half of years before
- November 41 year in 10 before October 21; 9 in 10 before November 19
NOAA puts the median frost-free season at 217 days, and the season without a hard freeze (28°F) at 247 days.
A hard freeze (28°F) comes after March 11 in half of springs and before November 14 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts McNary Dam #2 in zone 7b in ZIP code 97882, 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 USC00355392; 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 McNary Dam #2?
In a normal year in McNary Dam #2, 33 days a year reach 90°F (3 of them 100°F or more), 74 nights fall to 32°F or colder and 95 days bring measurable precipitation.
- Days at 90°F or more
- 33a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 74a normal year
- Days that stay below freezing
- 15high of 32°F or less
- Days with 0.01 inch of precipitation
- 95a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00355392.
How sunny is it at McNary Dam #2?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at McNary Dam #2, 4.2 kWh per square metre a day. July is the sunniest month (93%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.4 |
| February | 65% | 2.3 |
| March | 68% | 3.5 |
| April | 74% | 5.2 |
| May | 77% | 6.2 |
| June | 82% | 7.1 |
| July | 93% | 7.7 |
| August | 91% | 6.5 |
| September | 86% | 4.8 |
| October | 76% | 3.0 |
| November | 64% | 1.6 |
| December | 56% | 1.1 |
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 McNary Dam #2 record?
A normal year at McNary Dam #2 brings 4,821 heating degree days, 10% fewer than the median U.S. place (5,373), and 788 cooling degree days, 13% 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 3,096 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 913 | 0 |
| February | 729 | 0 |
| March | 609 | 0 |
| April | 385 | 1 |
| May | 175 | 20 |
| June | 47 | 100 |
| July | 2 | 296 |
| August | 2 | 288 |
| September | 59 | 80 |
| October | 339 | 4 |
| November | 662 | 0 |
| December | 900 | 0 |
| Year (annual) | 4,821 | 788 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00355392. 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 McNary Dam #2 been warmer than normal?
2025 averaged 55.6°F, 1.7°F above the 1991-2020 normal of 53.9°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.9°F | +1.0°F | 5.37 |
| 2022 | 52.9°F | −1.0°F | 9.79 |
| 2023 | 54.5°F | +0.6°F | 6.39 |
| 2024 | 54.6°F | +0.7°F | 9.04 |
| 2025 | 55.6°F | +1.7°F | 8.36 |
Source: observed years: ACIS, station USC00355392. A year counts only with all twelve months complete.
How does McNary Dam #2's climate compare?
McNary Dam #2 is warmer than 83 of the 105 places with their own NOAA record in Oregon, and wetter than 0. Across the 7,247 U.S. stations with normals, its annual mean of 53.9°F is warmer than 57%.
In the Köppen classification computed from these normals, McNary Dam #2 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 McNary Dam #2's climate
What is the coldest month at McNary Dam #2?
January, with a normal high of 41°F and a normal low of 30°F. The warmest is July (89°F by day, 61°F at night).
Does it snow at McNary Dam #2?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Boardman (20 miles away), records 4 inches of snow in a normal year.
What is the rainiest month at McNary Dam #2?
December, with 1.22 in of precipitation in a normal year; the driest is July with 0.19 in.
What plant hardiness zone is McNary Dam #2 in?
The USDA's 2023 map puts McNary Dam #2 in zone 7b in ZIP code 97882, the nearest ZIP area.
How late can frost come at McNary Dam #2?
In half of years the last 32°F night comes after March 30; in one year in ten it comes after April 20. Waiting until April 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- McNary Dam, WA1 miles from this station, 54.2°F a year
- Hermiston, OR7 miles from this station, 53.9°F a year
- Boardman, OR20 miles from this station, 54.0°F a year
- Kennewick, WA22 miles from this station, 55.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made