Billy Creek, Wyoming climate: Climate normals at a NOAA weather station
Billy Creek's normal year runs from 12°F January nights to 86°F July afternoons, with 13.4 inches of precipitation and 36 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.5°C, January lows of −11°C, July highs of 30°C, 342 mm of precipitation a year.
- NOAA stationBilly Creek
- Station IDUSC00480740
- Location44.12°N 106.73°W
- Elevation4,975 ft (1,516 m)
On October 12, the normal high in Billy Creek is 61°F and the normal low 32°F, and the chance of measurable rain or snow is 20%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Billy Creek.
- Jan 39° 12°
- Feb 40° 15°
- Mar 49° 22°
- Apr 55° 30°
- May 64° 39°
- Jun 76° 48°
- Jul 86° 55°
- Aug 84° 53°
- Sep 74° 43°
- Oct 60° 31°
- Nov 48° 21°
- Dec 39° 12°
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 Billy Creek each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 12°F. The most precipitation falls in May (2.79 in), the least in January (0.33 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 39°F | 12°F | 25.3°F | 0.33 | 5.0 | 5 | <1 | 30 | 9 h 10 min |
| February | 40°F | 15°F | 27.1°F | 0.40 | 5.2 | 5 | <1 | 27 | 10 h 30 min |
| March | 49°F | 22°F | 35.6°F | 0.63 | 5.5 | 6 | <1 | 27 | 11 h 50 min |
| April | 55°F | 30°F | 42.5°F | 1.54 | 6.2 | 9 | <1 | 20 | 13 h 20 min |
| May | 64°F | 39°F | 51.6°F | 2.79 | 1.1 | 12 | <1 | 7 | 14 h 40 min |
| June | 76°F | 48°F | 61.8°F | 2.08 | 0.0 | 11 | 2 | 1 | 15 h 30 min |
| July | 86°F | 55°F | 70.1°F | 1.55 | 0.0 | 8 | 11 | <1 | 15 h 10 min |
| August | 84°F | 53°F | 68.3°F | 0.84 | 0.0 | 6 | 10 | <1 | 14 h |
| September | 74°F | 43°F | 58.7°F | 1.29 | 0.2 | 6 | 2 | 4 | 12 h 40 min |
| October | 60°F | 31°F | 45.2°F | 1.13 | 3.1 | 6 | <1 | 18 | 11 h 10 min |
| November | 48°F | 21°F | 34.3°F | 0.52 | 4.8 | 5 | <1 | 27 | 9 h 40 min |
| December | 39°F | 12°F | 25.7°F | 0.35 | 4.6 | 4 | <1 | 31 | 8 h 50 min |
| Year (annual) | 59°F | 32°F | 45.5°F | 13.45 | 35.7 | 83 | 26 | 192 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −11°C | −3.7°C | 8 mm | 13 cm |
| February | 4°C | −10°C | −2.7°C | 10 mm | 13 cm |
| March | 9°C | −5°C | 2.0°C | 16 mm | 14 cm |
| April | 13°C | −1°C | 5.8°C | 39 mm | 16 cm |
| May | 18°C | 4°C | 10.9°C | 71 mm | 3 cm |
| June | 24°C | 9°C | 16.6°C | 53 mm | 0 cm |
| July | 30°C | 13°C | 21.2°C | 39 mm | 0 cm |
| August | 29°C | 12°C | 20.2°C | 21 mm | 0 cm |
| September | 24°C | 6°C | 14.8°C | 33 mm | 1 cm |
| October | 15°C | −1°C | 7.3°C | 29 mm | 8 cm |
| November | 9°C | −6°C | 1.3°C | 13 mm | 12 cm |
| December | 4°C | −11°C | −3.5°C | 9 mm | 12 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00480740; 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 Billy Creek?
Normal highs sit between 65°F and 85°F in June, August and September. Of those, August has the fewest days with rain (6).
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 USC00480740.
When is the last frost at Billy Creek?
In Billy Creek, the last spring frost (32°F) comes after May 19 in half of years and after May 31 in one year in ten; the first autumn frost comes before September 21 in half of years and before September 6 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 191 year in 10 after May 31; 9 in 10 after May 7
- First autumn frost, half of years before
- September 211 year in 10 before September 6; 9 in 10 before October 4
NOAA puts the median frost-free season at 123 days, and the season without a hard freeze (28°F) at 145 days.
A hard freeze (28°F) comes after May 8 in half of springs and before September 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Billy Creek in zone 5a in ZIP code 82834, 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 −20°F (18 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 Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00480740; 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 Billy Creek?
In a normal year in Billy Creek, 26 days a year reach 90°F (2 of them 100°F or more), 192 nights fall to 32°F or colder and 83 days bring measurable precipitation.
- Days at 90°F or more
- 26a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 192a normal year
- Days that stay below freezing
- 36high of 32°F or less
- Days with 0.01 inch of precipitation
- 83a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1962) is 107°F, on July 26, 2000; the lowest is −41°F, on February 3, 1989.
The wettest calendar year on that record is 1968, with 19.52 in; the snowiest season is 1977–78, with 84.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00480740; records: ACIS (NOAA Regional Climate Centers), station USC00480740. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Billy Creek?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds at Billy Creek, 4.3 kWh per square metre a day. July is the sunniest month (86%) and April the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 74% | 1.9 |
| February | 73% | 2.8 |
| March | 72% | 4.0 |
| April | 70% | 5.0 |
| May | 72% | 5.9 |
| June | 80% | 7.0 |
| July | 86% | 7.2 |
| August | 85% | 6.1 |
| September | 82% | 4.8 |
| October | 75% | 3.1 |
| November | 73% | 2.1 |
| December | 70% | 1.6 |
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 Billy Creek record?
A normal year at Billy Creek brings 7,516 heating degree days, 40% more than the median U.S. place (5,373), and 452 cooling degree days, 50% 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 2,123 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,229 | 0 |
| February | 1,060 | 0 |
| March | 913 | 0 |
| April | 676 | 1 |
| May | 420 | 6 |
| June | 149 | 54 |
| July | 35 | 193 |
| August | 52 | 156 |
| September | 231 | 42 |
| October | 615 | 2 |
| November | 921 | 0 |
| December | 1,217 | 0 |
| Year (annual) | 7,516 | 452 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00480740. 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.
How does Billy Creek's climate compare?
Billy Creek is warmer than 48 of the 71 places with their own NOAA record in Wyoming, and wetter than 39. Across the 7,247 U.S. stations with normals, its annual mean of 45.5°F is warmer than 21%.
In the Köppen classification computed from these normals, Billy Creek 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 Billy Creek's climate
What is the coldest month at Billy Creek?
January, with a normal high of 39°F and a normal low of 12°F. The warmest is July (86°F by day, 55°F at night).
Does it snow at Billy Creek?
Yes: 36 inches in a normal year, falling on 28 days with 0.1 inch or more, the most in April (6.2 inches).
What is the rainiest month at Billy Creek?
May, with 2.79 in of precipitation in a normal year; the driest is January with 0.33 in.
What plant hardiness zone is Billy Creek in?
The USDA's 2023 map puts Billy Creek in zone 5a in ZIP code 82834, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −20°F (18 years, 1991-2020): zone 4b.
How late can frost come at Billy Creek?
In half of years the last 32°F night comes after May 19; in one year in ten it comes after May 31. Waiting until May 31 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Buffalo, WY18 miles from this station, 46.4°F a year
- Kaycee, WY29 miles from this station, 45.2°F a year
- Story, WY32 miles from this station, 43.5°F a year
- Tensleep (4 mi NE), WY32 miles from this station, 47.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made