Tolt S Fork Reservoir, Washington climate: Climate normals at a NOAA weather station
Tolt S Fork Reservoir's normal year runs from 32°F December nights to 72°F August afternoons, with 104.3 inches of precipitation and 55 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.9°C, December lows of 0°C, August highs of 22°C, 2,650 mm of precipitation a year.
- NOAA stationTolt S Fork Reservoir
- Station IDUSC00458508
- Location47.70°N 121.69°W
- Elevation2,000 ft (610 m)
On October 23, the normal high in Tolt S Fork Reservoir is 52°F and the normal low 41°F, and the chance of measurable rain or snow is 63%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Tolt S Fork Reservoir.
- Jan 41° 33°
- Feb 43° 33°
- Mar 46° 34°
- Apr 52° 37°
- May 61° 44°
- Jun 65° 49°
- Jul 72° 54°
- Aug 72° 54°
- Sep 66° 50°
- Oct 55° 43°
- Nov 45° 36°
- Dec 40° 32°
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 Tolt S Fork Reservoir each month?
August is the warmest month, with normal highs of 72°F; December the coldest, with normal lows of 32°F. The most precipitation falls in November (14.51 in), the least in August (2.41 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 33°F | 36.9°F | 13.63 | 12.0 | 22 | <1 | 16 | 8 h 50 min |
| February | 43°F | 33°F | 37.7°F | 9.22 | 9.4 | 19 | <1 | 17 | 10 h 10 min |
| March | 46°F | 34°F | 39.7°F | 11.47 | 9.8 | 23 | <1 | 14 | 11 h 50 min |
| April | 52°F | 37°F | 44.6°F | 9.67 | 4.7 | 21 | <1 | 5 | 13 h 30 min |
| May | 61°F | 44°F | 52.0°F | 6.94 | 0.4 | 18 | <1 | 1 | 15 h 10 min |
| June | 65°F | 49°F | 56.7°F | 6.06 | 0.0 | 16 | <1 | <1 | 16 h |
| July | 72°F | 54°F | 62.8°F | 2.54 | 0.0 | 9 | 1 | <1 | 15 h 40 min |
| August | 72°F | 54°F | 63.1°F | 2.41 | 0.0 | 9 | 2 | <1 | 14 h 20 min |
| September | 66°F | 50°F | 58.1°F | 5.58 | 0.0 | 13 | <1 | <1 | 12 h 40 min |
| October | 55°F | 43°F | 48.7°F | 10.47 | 0.2 | 18 | <1 | 1 | 11 h |
| November | 45°F | 36°F | 40.8°F | 14.51 | 8.2 | 22 | <1 | 7 | 9 h 20 min |
| December | 40°F | 32°F | 35.8°F | 11.84 | 10.5 | 22 | <1 | 17 | 8 h 30 min |
| Year (annual) | 55°F | 42°F | 48.1°F | 104.34 | 55.2 | 211 | 3 | 77 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | 0°C | 2.7°C | 346 mm | 30 cm |
| February | 6°C | 0°C | 3.2°C | 234 mm | 24 cm |
| March | 8°C | 1°C | 4.3°C | 291 mm | 25 cm |
| April | 11°C | 3°C | 7.0°C | 246 mm | 12 cm |
| May | 16°C | 6°C | 11.1°C | 176 mm | 1 cm |
| June | 18°C | 9°C | 13.7°C | 154 mm | 0 cm |
| July | 22°C | 12°C | 17.1°C | 65 mm | 0 cm |
| August | 22°C | 12°C | 17.3°C | 61 mm | 0 cm |
| September | 19°C | 10°C | 14.5°C | 142 mm | 0 cm |
| October | 13°C | 6°C | 9.3°C | 266 mm | 1 cm |
| November | 7°C | 2°C | 4.9°C | 369 mm | 21 cm |
| December | 4°C | 0°C | 2.1°C | 301 mm | 27 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00458508; 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 Tolt S Fork Reservoir?
Normal highs sit between 65°F and 85°F in July, August and September. Of those, August has the fewest days with rain (9).
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 USC00458508.
When is the last frost at Tolt S Fork Reservoir?
In Tolt S Fork Reservoir, the last spring frost (32°F) comes after April 13 in half of years and after May 4 in one year in ten; the first autumn frost comes before November 10 in half of years and before October 24 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 131 year in 10 after May 4; 9 in 10 after March 23
- First autumn frost, half of years before
- November 101 year in 10 before October 24; 9 in 10 before November 28
NOAA puts the median frost-free season at 210 days, and the season without a hard freeze (28°F) at 261 days.
A hard freeze (28°F) comes after March 14 in half of springs and before November 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Tolt S Fork Reservoir in zone 8a in ZIP code 98224, the nearest ZIP area.
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00458508; 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 Tolt S Fork Reservoir?
In a normal year in Tolt S Fork Reservoir, 3 days a year reach 90°F, 77 nights fall to 32°F or colder and 211 days bring measurable precipitation.
- Days at 90°F or more
- 3a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 77a normal year
- Days that stay below freezing
- 12high of 32°F or less
- Days with 0.01 inch of precipitation
- 211a normal year
- Days with 1 inch of snow or more
- 18a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00458508.
How sunny is it at Tolt S Fork Reservoir?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds at Tolt S Fork Reservoir, 3.8 kWh per square metre a day. July is the sunniest month (86%) and December the cloudiest (54%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 56% | 1.2 |
| February | 64% | 2.1 |
| March | 63% | 3.1 |
| April | 67% | 4.6 |
| May | 70% | 5.7 |
| June | 74% | 6.3 |
| July | 86% | 7.0 |
| August | 85% | 5.9 |
| September | 79% | 4.3 |
| October | 69% | 2.5 |
| November | 58% | 1.3 |
| December | 54% | 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 Tolt S Fork Reservoir record?
A normal year at Tolt S Fork Reservoir brings 6,287 heating degree days, 17% more than the median U.S. place (5,373), and 136 cooling degree days, 85% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,484 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 871 | 0 |
| February | 763 | 0 |
| March | 784 | 0 |
| April | 614 | 0 |
| May | 404 | 2 |
| June | 267 | 17 |
| July | 119 | 51 |
| August | 111 | 52 |
| September | 221 | 14 |
| October | 504 | 0 |
| November | 726 | 0 |
| December | 904 | 0 |
| Year (annual) | 6,287 | 136 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00458508. 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 Tolt S Fork Reservoir been warmer than normal?
2024 averaged 49.1°F, 1.0°F above the 1991-2020 normal of 48.1°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.0°F | +0.9°F | 108.05 | 99.8 |
| 2022 | 49.4°F | +1.3°F | 108.27 | 90.5 |
| 2023 | 50.0°F | +1.9°F | 85.30 | 51.8 |
| 2024 | 49.1°F | +1.0°F | 105.82 | 40.5 |
Source: observed years: ACIS, station USC00458508. A year counts only with all twelve months complete.
How does Tolt S Fork Reservoir's climate compare?
Tolt S Fork Reservoir is warmer than 16 of the 96 places with their own NOAA record in Washington, and wetter than 86. Across the 7,247 U.S. stations with normals, its annual mean of 48.1°F is warmer than 32%.
In the Köppen classification computed from these normals, Tolt S Fork Reservoir is Cfb: temperate, no dry season, 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 Tolt S Fork Reservoir share this climate record?
Lake Marcel-Stillwater 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.
- Lake Marcel-Stillwater, WA1,463 people · 10 mi W
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 Tolt S Fork Reservoir's climate
What is the coldest month at Tolt S Fork Reservoir?
December, with a normal high of 40°F and a normal low of 32°F. The warmest is August (72°F by day, 54°F at night).
Does it snow at Tolt S Fork Reservoir?
Yes: 55 inches in a normal year, falling on 22 days with 0.1 inch or more, the most in January (12.0 inches).
What is the rainiest month at Tolt S Fork Reservoir?
November, with 14.51 in of precipitation in a normal year; the driest is August with 2.41 in.
What plant hardiness zone is Tolt S Fork Reservoir in?
The USDA's 2023 map puts Tolt S Fork Reservoir in zone 8a in ZIP code 98224, the nearest ZIP area.
How late can frost come at Tolt S Fork Reservoir?
In half of years the last 32°F night comes after April 13; in one year in ten it comes after May 4. Waiting until May 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Baring, WA11 miles from this station, 49.7°F a year
- Startup, WA12 miles from this station, 51.6°F a year
- Snoqualmie, WA13 miles from this station, 51.7°F a year
- Monroe, WA17 miles from this station, 49.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made