Williams Fork Dam, Colorado climate: Climate normals at a NOAA weather station
Williams Fork Dam's normal year runs from 0°F January nights to 79°F July afternoons, with 14.3 inches of precipitation and 81 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 3.4°C, January lows of −18°C, July highs of 26°C, 362 mm of precipitation a year.
- NOAA stationWilliams Fork Dam
- Station IDUSC00059096
- Location40.04°N 106.20°W
- Elevation7,618 ft (2,322 m)
On October 23, the normal high in Williams Fork Dam is 53°F and the normal low 23°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Williams Fork Dam.
- Jan 26° 0°
- Feb 31° 4°
- Mar 42° 15°
- Apr 52° 24°
- May 62° 32°
- Jun 73° 38°
- Jul 79° 45°
- Aug 77° 43°
- Sep 70° 35°
- Oct 57° 25°
- Nov 41° 15°
- Dec 28° 4°
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 Williams Fork Dam each month?
July is the warmest month, with normal highs of 79°F; January the coldest, with normal lows of 0°F. The most precipitation falls in May (1.53 in), the least in December (0.88 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 26°F | 0°F | 13.0°F | 1.00 | 14.2 | 10 | <1 | 31 | 9 h 40 min |
| February | 31°F | 4°F | 17.4°F | 0.95 | 13.6 | 10 | <1 | 28 | 10 h 40 min |
| March | 42°F | 15°F | 28.5°F | 0.98 | 10.4 | 8 | <1 | 31 | 11 h 50 min |
| April | 52°F | 24°F | 37.9°F | 1.46 | 11.9 | 10 | <1 | 28 | 13 h 10 min |
| May | 62°F | 32°F | 46.9°F | 1.53 | 2.7 | 10 | <1 | 19 | 14 h 20 min |
| June | 73°F | 38°F | 55.8°F | 0.99 | 0.1 | 7 | <1 | 4 | 15 h |
| July | 79°F | 45°F | 61.9°F | 1.44 | 0.0 | 9 | <1 | <1 | 14 h 50 min |
| August | 77°F | 43°F | 60.1°F | 1.44 | 0.0 | 10 | <1 | 1 | 13 h 50 min |
| September | 70°F | 35°F | 52.5°F | 1.40 | 0.3 | 8 | <1 | 12 | 12 h 30 min |
| October | 57°F | 25°F | 41.0°F | 1.26 | 4.8 | 8 | <1 | 27 | 11 h 10 min |
| November | 41°F | 15°F | 27.9°F | 0.92 | 9.9 | 8 | <1 | 30 | 10 h |
| December | 28°F | 4°F | 15.8°F | 0.88 | 13.3 | 9 | <1 | 31 | 9 h 20 min |
| Year (annual) | 53°F | 23°F | 38.2°F | 14.25 | 81.2 | 107 | <1 | 242 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −18°C | −10.6°C | 25 mm | 36 cm |
| February | 0°C | −16°C | −8.1°C | 24 mm | 35 cm |
| March | 6°C | −10°C | −1.9°C | 25 mm | 26 cm |
| April | 11°C | −5°C | 3.3°C | 37 mm | 30 cm |
| May | 17°C | 0°C | 8.3°C | 39 mm | 7 cm |
| June | 23°C | 4°C | 13.2°C | 25 mm | 0 cm |
| July | 26°C | 7°C | 16.6°C | 37 mm | 0 cm |
| August | 25°C | 6°C | 15.6°C | 37 mm | 0 cm |
| September | 21°C | 2°C | 11.4°C | 36 mm | 1 cm |
| October | 14°C | −4°C | 5.0°C | 32 mm | 12 cm |
| November | 5°C | −10°C | −2.3°C | 23 mm | 25 cm |
| December | −2°C | −16°C | −9.0°C | 22 mm | 34 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00059096; 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 Williams Fork Dam?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, June 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 USC00059096.
When is the last frost at Williams Fork Dam?
In Williams Fork Dam, the last spring frost (32°F) comes after June 12 in half of years and after June 25 in one year in ten; the first autumn frost comes before September 10 in half of years and before August 31 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
- June 121 year in 10 after June 25; 9 in 10 after May 31
- First autumn frost, half of years before
- September 101 year in 10 before August 31; 9 in 10 before September 21
NOAA puts the median frost-free season at 89 days, and the season without a hard freeze (28°F) at 115 days.
A hard freeze (28°F) comes after May 26 in half of springs and before September 20 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Williams Fork Dam in zone 5a in ZIP code 80468, 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 4b: the coldest night of a typical year reaches −24°F (30 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 Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00059096; 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 Williams Fork Dam?
In a normal year in Williams Fork Dam, a 90°F day is rare, 242 nights fall to 32°F or colder and 107 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 242a normal year
- Days that stay below freezing
- 67high of 32°F or less
- Days with 0.01 inch of precipitation
- 107a normal year
- Days with 1 inch of snow or more
- 38a normal year
The highest temperature in this station's record (since 1982) is 99°F, on August 8, 2026; the lowest is −44°F, on February 8, 1989.
The wettest calendar year on that record is 1985, with 21.65 in; the snowiest season is 2013–14, with 125.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00059096; records: ACIS (NOAA Regional Climate Centers), station USC00059096. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Williams Fork Dam?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds at Williams Fork Dam, 4.7 kWh per square metre a day. June is the sunniest month (82%) and December the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 73% | 2.4 |
| February | 73% | 3.3 |
| March | 77% | 4.8 |
| April | 73% | 5.6 |
| May | 73% | 6.3 |
| June | 82% | 7.5 |
| July | 81% | 7.0 |
| August | 79% | 6.0 |
| September | 81% | 5.2 |
| October | 75% | 3.6 |
| November | 72% | 2.5 |
| December | 69% | 2.0 |
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 Williams Fork Dam record?
A normal year at Williams Fork Dam brings 9,756 heating degree days, 82% more than the median U.S. place (5,373), and 18 cooling degree days, 98% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,036 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,612 | 0 |
| February | 1,333 | 0 |
| March | 1,133 | 0 |
| April | 813 | 0 |
| May | 561 | 0 |
| June | 279 | 1 |
| July | 110 | 12 |
| August | 159 | 5 |
| September | 375 | 0 |
| October | 744 | 0 |
| November | 1,115 | 0 |
| December | 1,524 | 0 |
| Year (annual) | 9,756 | 18 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00059096. 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 Williams Fork Dam been warmer than normal?
2025 averaged 41.0°F, 2.8°F above the 1991-2020 normal of 38.2°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 39.8°F | +1.6°F | 15.38 | 76.4 |
| 2022 | 35.4°F | −2.8°F | 15.89 | 96.7 |
| 2024 | 38.7°F | +0.5°F | 16.33 | 99.9 |
| 2025 | 41.0°F | +2.8°F | 10.86 | 49.8 |
Over 35 complete years from 1983 to 2025, the station's annual mean temperature rose at a fitted 6.1°F per century (+0.34°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00059096; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Williams Fork Dam's climate compare?
Williams Fork Dam is warmer than 12 of the 125 places with their own NOAA record in Colorado, and wetter than 42. Across the 7,247 U.S. stations with normals, its annual mean of 38.2°F is warmer than 3%.
In the Köppen classification computed from these normals, Williams Fork Dam is Dfb: continental, 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 Williams Fork Dam share this climate record?
2 places have no NOAA station with 1991-2020 normals of their 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.
- Hot Sulphur Springs, CO654 people · 6 mi NE
- Parshall, CO34 people · 2 mi NE
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 Williams Fork Dam's climate
What is the coldest month at Williams Fork Dam?
January, with a normal high of 26°F and a normal low of 0°F. The warmest is July (79°F by day, 45°F at night).
Does it snow at Williams Fork Dam?
Yes: 81 inches in a normal year, falling on 43 days with 0.1 inch or more, the most in January (14.2 inches).
What is the rainiest month at Williams Fork Dam?
May, with 1.53 in of precipitation in a normal year; the driest is December with 0.88 in.
What plant hardiness zone is Williams Fork Dam in?
The USDA's 2023 map puts Williams Fork Dam in zone 5a in ZIP code 80468, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −24°F (30 years, 1991-2020): zone 4b.
How late can frost come at Williams Fork Dam?
In half of years the last 32°F night comes after June 12; in one year in ten it comes after June 25. Waiting until June 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Kremmling, CO9 miles from this station, 38.5°F a year
- Green Mount Dam, CO13 miles from this station, 38.6°F a year
- Fraser, CO22 miles from this station, 36.0°F a year
- Grand Lake, CO25 miles from this station, 36.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made