Newhalem, Washington climate: Climate normals at a NOAA weather station
Newhalem's normal year runs from 33°F December nights to 79°F August afternoons, with 78.8 inches of precipitation and 30 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, December lows of 0°C, August highs of 26°C, 2,003 mm of precipitation a year.
- NOAA stationNewhalem
- Station IDUSC00455840
- Location48.68°N 121.24°W
- Elevation525 ft (160 m)
On October 23, the normal high in Newhalem is 53°F and the normal low 42°F, and the chance of measurable rain or snow is 60%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Newhalem.
- Jan 40° 32°
- Feb 44° 33°
- Mar 49° 35°
- Apr 58° 40°
- May 67° 46°
- Jun 70° 50°
- Jul 78° 54°
- Aug 79° 54°
- Sep 71° 50°
- Oct 57° 44°
- Nov 45° 37°
- Dec 40° 33°
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 Newhalem each month?
August is the warmest month, with normal highs of 79°F; December the coldest, with normal lows of 33°F. The most precipitation falls in November (13.58 in), the least in July (1.40 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 32°F | 36.2°F | 12.40 | 10.2 | 19 | <1 | 14 | 8 h 40 min |
| February | 44°F | 33°F | 38.3°F | 7.16 | 7.7 | 15 | <1 | 12 | 10 h 10 min |
| March | 49°F | 35°F | 42.2°F | 8.36 | 2.8 | 19 | <1 | 9 | 11 h 50 min |
| April | 58°F | 40°F | 48.7°F | 4.65 | 0.1 | 17 | <1 | 2 | 13 h 40 min |
| May | 67°F | 46°F | 56.1°F | 3.01 | 0.0 | 13 | 1 | <1 | 15 h 10 min |
| June | 70°F | 50°F | 60.2°F | 2.58 | 0.0 | 13 | 2 | <1 | 16 h 10 min |
| July | 78°F | 54°F | 65.8°F | 1.40 | 0.0 | 7 | 4 | <1 | 15 h 50 min |
| August | 79°F | 54°F | 66.4°F | 1.68 | 0.0 | 7 | 4 | <1 | 14 h 30 min |
| September | 71°F | 50°F | 60.6°F | 3.55 | 0.0 | 11 | 1 | <1 | 12 h 40 min |
| October | 57°F | 44°F | 50.3°F | 8.78 | 0.0 | 17 | <1 | <1 | 10 h 50 min |
| November | 45°F | 37°F | 41.2°F | 13.58 | 2.4 | 21 | <1 | 6 | 9 h 10 min |
| December | 40°F | 33°F | 36.0°F | 11.70 | 6.3 | 19 | <1 | 15 | 8 h 20 min |
| Year (annual) | 58°F | 42°F | 50.2°F | 78.85 | 29.5 | 177 | 11 | 58 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | 0°C | 2.3°C | 315 mm | 26 cm |
| February | 7°C | 0°C | 3.5°C | 182 mm | 20 cm |
| March | 10°C | 2°C | 5.7°C | 212 mm | 7 cm |
| April | 14°C | 4°C | 9.3°C | 118 mm | 0 cm |
| May | 19°C | 8°C | 13.4°C | 76 mm | 0 cm |
| June | 21°C | 10°C | 15.7°C | 66 mm | 0 cm |
| July | 26°C | 12°C | 18.8°C | 36 mm | 0 cm |
| August | 26°C | 12°C | 19.1°C | 43 mm | 0 cm |
| September | 22°C | 10°C | 15.9°C | 90 mm | 0 cm |
| October | 14°C | 7°C | 10.2°C | 223 mm | 0 cm |
| November | 7°C | 3°C | 5.1°C | 345 mm | 6 cm |
| December | 4°C | 0°C | 2.2°C | 297 mm | 16 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00455840; 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 Newhalem?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, August has the fewest days with rain (7).
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 USC00455840.
When is the last frost at Newhalem?
In Newhalem, the last spring frost (32°F) comes after April 2 in half of years and after April 27 in one year in ten; the first autumn frost comes before November 14 in half of years and before October 28 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
- April 21 year in 10 after April 27; 9 in 10 after March 9
- First autumn frost, half of years before
- November 141 year in 10 before October 28; 9 in 10 before December 5
NOAA puts the median frost-free season at 224 days, and the season without a hard freeze (28°F) at 277 days.
A hard freeze (28°F) comes after March 2 in half of springs and before December 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Newhalem in zone 7a in ZIP code 98283, 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 8b: the coldest night of a typical year reaches 16°F (29 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00455840; 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 Newhalem?
In a normal year in Newhalem, 11 days a year reach 90°F, 58 nights fall to 32°F or colder and 177 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 58a normal year
- Days that stay below freezing
- 6high of 32°F or less
- Days with 0.01 inch of precipitation
- 177a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1909) is 113°F, on June 29, 2021; the lowest is 1°F, on January 20, 1935.
The wettest calendar year on that record is 1959, with 102.85 in; the snowiest season is 1948–49, with 144.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00455840; records: ACIS (NOAA Regional Climate Centers), station USC00455840. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Newhalem?
Over a year 68% of the sunlight that would reach the ground under clear skies gets through the clouds at Newhalem, 3.5 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (53%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 55% | 1.1 |
| February | 62% | 2.0 |
| March | 59% | 2.9 |
| April | 63% | 4.3 |
| May | 66% | 5.3 |
| June | 67% | 5.8 |
| July | 81% | 6.7 |
| August | 81% | 5.7 |
| September | 75% | 4.0 |
| October | 64% | 2.3 |
| November | 55% | 1.2 |
| December | 53% | 0.9 |
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 Newhalem record?
A normal year at Newhalem brings 5,644 heating degree days, 5% more than the median U.S. place (5,373), and 257 cooling degree days, 72% 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 1,980 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 894 | 0 |
| February | 748 | 0 |
| March | 707 | 0 |
| April | 490 | 1 |
| May | 288 | 12 |
| June | 175 | 29 |
| July | 62 | 88 |
| August | 52 | 97 |
| September | 160 | 29 |
| October | 455 | 0 |
| November | 716 | 0 |
| December | 899 | 0 |
| Year (annual) | 5,644 | 257 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00455840. 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 Newhalem been warmer than normal?
2025 averaged 52.0°F, 1.8°F above the 1991-2020 normal of 50.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 50.6°F | +0.4°F | 93.82 | 29.7 |
| 2022 | 50.2°F | at normal | 67.94 | 52.2 |
| 2023 | 51.8°F | +1.6°F | 50.68 | 15.8 |
| 2024 | 51.3°F | +1.1°F | 65.47 | 24.3 |
| 2025 | 52.0°F | +1.8°F | 79.07 | 6.4 |
Over 49 complete years from 1959 to 2025, the station's annual mean temperature rose at a fitted 3.5°F per century (+0.20°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00455840; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Newhalem's climate compare?
Newhalem is warmer than 44 of the 96 places with their own NOAA record in Washington, and wetter than 82. Across the 7,247 U.S. stations with normals, its annual mean of 50.2°F is warmer than 41%.
In the Köppen classification computed from these normals, Newhalem 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 Newhalem share this climate record?
Marblemount has no NOAA station with 1991-2020 normals of its 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.
- Marblemount, WA318 people · 13 mi SW
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 Newhalem's climate
What is the coldest month at Newhalem?
December, with a normal high of 40°F and a normal low of 33°F. The warmest is August (79°F by day, 54°F at night).
Does it snow at Newhalem?
Yes: 30 inches in a normal year, falling on 12 days with 0.1 inch or more, the most in January (10.2 inches).
What is the rainiest month at Newhalem?
November, with 13.58 in of precipitation in a normal year; the driest is July with 1.40 in.
What plant hardiness zone is Newhalem in?
The USDA's 2023 map puts Newhalem in zone 7a in ZIP code 98283, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 16°F (29 years, 1991-2020): zone 8b.
How late can frost come at Newhalem?
In half of years the last 32°F night comes after April 2; in one year in ten it comes after April 27. Waiting until April 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Diablo Dam, WA5 miles from this station, 49.2°F a year
- Ross Dam, WA9 miles from this station, 49.1°F a year
- Upper Baker Dam, WA21 miles from this station, 47.4°F a year
- Concrete, WA25 miles from this station, 50.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made