Whalen Dam USBR, Wyoming climate: Climate normals at a NOAA weather station
Whalen Dam USBR's normal year runs from 13°F December nights to 88°F July afternoons, with 14.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.9°C, December lows of −10°C, July highs of 31°C, 359 mm of precipitation a year.
- NOAA stationWhalen Dam USBR
- Station IDUSC00489604
- Location42.25°N 104.63°W
- Elevation4,294 ft (1,309 m)
On October 23, the normal high in Whalen Dam USBR is 60°F and the normal low 29°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Whalen Dam USBR.
- Jan 41° 14°
- Feb 42° 15°
- Mar 53° 24°
- Apr 60° 32°
- May 69° 42°
- Jun 81° 51°
- Jul 88° 58°
- Aug 87° 56°
- Sep 78° 46°
- Oct 63° 32°
- Nov 50° 22°
- Dec 41° 13°
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 Whalen Dam USBR each month?
July is the warmest month, with normal highs of 88°F; December the coldest, with normal lows of 13°F. The most precipitation falls in May (2.70 in), the least in January (0.25 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 41°F | 14°F | 27.4°F | 0.25 | – | <1 | 30 | 9 h 20 min |
| February | 42°F | 15°F | 28.4°F | 0.38 | – | <1 | 27 | 10 h 30 min |
| March | 53°F | 24°F | 38.3°F | 0.80 | – | <1 | 24 | 11 h 50 min |
| April | 60°F | 32°F | 45.7°F | 1.78 | – | <1 | 15 | 13 h 20 min |
| May | 69°F | 42°F | 55.3°F | 2.70 | – | <1 | 3 | 14 h 30 min |
| June | 81°F | 51°F | 66.0°F | 2.10 | – | 8 | <1 | 15 h 10 min |
| July | 88°F | 58°F | 73.1°F | 1.79 | – | 15 | <1 | 15 h |
| August | 87°F | 56°F | 71.5°F | 1.26 | – | 12 | <1 | 14 h |
| September | 78°F | 46°F | 61.7°F | 1.21 | – | 5 | 1 | 12 h 30 min |
| October | 63°F | 32°F | 47.7°F | 1.12 | – | <1 | 16 | 11 h 10 min |
| November | 50°F | 22°F | 35.8°F | 0.45 | – | <1 | 27 | 9 h 50 min |
| December | 41°F | 13°F | 26.9°F | 0.30 | – | <1 | 30 | 9 h 10 min |
| Year (annual) | 63°F | 34°F | 48.1°F | 14.14 | – | 39 | 174 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −10°C | −2.6°C | 6 mm |
| February | 5°C | −9°C | −2.0°C | 10 mm |
| March | 12°C | −5°C | 3.5°C | 20 mm |
| April | 15°C | 0°C | 7.6°C | 45 mm |
| May | 20°C | 5°C | 12.9°C | 69 mm |
| June | 27°C | 11°C | 18.9°C | 53 mm |
| July | 31°C | 14°C | 22.8°C | 45 mm |
| August | 31°C | 13°C | 21.9°C | 32 mm |
| September | 25°C | 8°C | 16.5°C | 31 mm |
| October | 17°C | 0°C | 8.7°C | 28 mm |
| November | 10°C | −6°C | 2.1°C | 11 mm |
| December | 5°C | −10°C | −2.8°C | 8 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Old Fort Laramie (5 miles away), gets 28 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00489604; 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 Whalen Dam USBR?
Normal highs sit between 65°F and 85°F in May, June and September.
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 USC00489604.
When is the last frost at Whalen Dam USBR?
In Whalen Dam USBR, the last spring frost (32°F) comes after May 7 in half of years and after May 24 in one year in ten; the first autumn frost comes before October 3 in half of years and before September 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
- May 71 year in 10 after May 24; 9 in 10 after April 25
- First autumn frost, half of years before
- October 31 year in 10 before September 21; 9 in 10 before October 14
NOAA puts the median frost-free season at 146 days, and the season without a hard freeze (28°F) at 164 days.
A hard freeze (28°F) comes after April 27 in half of springs and before October 13 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Whalen Dam USBR in zone 5a in ZIP code 82212, the nearest ZIP area.
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00489604; 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 Whalen Dam USBR?
In a normal year in Whalen Dam USBR, 39 days a year reach 90°F (2 of them 100°F or more) and 174 nights fall to 32°F or colder.
- Days at 90°F or more
- 39a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 174a normal year
- Days that stay below freezing
- 29high of 32°F or less
The highest temperature in this station's record (since 1949) is 114°F, on June 24, 1988; the lowest is −43°F, on December 22, 1989.
The wettest calendar year on that record is 1965, with 19.57 in; the snowiest season is 1990–91, with 19.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00489604; records: ACIS (NOAA Regional Climate Centers), station USC00489604. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Whalen Dam USBR?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at Whalen Dam USBR, 4.5 kWh per square metre a day. July is the sunniest month (86%) and February the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.1 |
| February | 72% | 2.9 |
| March | 73% | 4.2 |
| April | 72% | 5.2 |
| May | 74% | 6.2 |
| June | 82% | 7.2 |
| July | 86% | 7.1 |
| August | 86% | 6.3 |
| September | 84% | 5.0 |
| October | 77% | 3.4 |
| November | 76% | 2.4 |
| December | 72% | 1.8 |
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 Whalen Dam USBR record?
A normal year at Whalen Dam USBR brings 6,731 heating degree days, 25% more than the median U.S. place (5,373), and 619 cooling degree days, 32% 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 2,580 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,166 | 0 |
| February | 1,024 | 0 |
| March | 828 | 0 |
| April | 579 | 0 |
| May | 315 | 13 |
| June | 58 | 87 |
| July | 3 | 254 |
| August | 13 | 215 |
| September | 149 | 50 |
| October | 537 | 1 |
| November | 876 | 0 |
| December | 1,182 | 0 |
| Year (annual) | 6,731 | 619 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00489604. 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 Whalen Dam USBR been warmer than normal?
2022 averaged 48.9°F, 0.8°F above the 1991-2020 normal of 48.1°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 49.2°F | +1.1°F | 8.11 |
| 2022 | 48.9°F | +0.8°F | 7.71 |
Over 39 complete years from 1951 to 2022, the station's annual mean temperature rose at a fitted 3.8°F per century (+0.21°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00489604; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Whalen Dam USBR's climate compare?
Whalen Dam USBR is warmer than 63 of the 71 places with their own NOAA record in Wyoming, and wetter than 41. 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, Whalen Dam USBR 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 Whalen Dam USBR's climate
What is the coldest month at Whalen Dam USBR?
December, with a normal high of 41°F and a normal low of 13°F. The warmest is July (88°F by day, 58°F at night).
Does it snow at Whalen Dam USBR?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Old Fort Laramie (5 miles away), records 28 inches of snow in a normal year.
What is the rainiest month at Whalen Dam USBR?
May, with 2.70 in of precipitation in a normal year; the driest is January with 0.25 in.
What plant hardiness zone is Whalen Dam USBR in?
The USDA's 2023 map puts Whalen Dam USBR in zone 5a in ZIP code 82212, the nearest ZIP area.
How late can frost come at Whalen Dam USBR?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 24. Waiting until May 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Old Fort Laramie, WY5 miles from this station, 49.1°F a year
- Guernsey, WY7 miles from this station, 48.7°F a year
- Lingle, WY15 miles from this station, 46.9°F a year
- Wheatland, WY19 miles from this station, 49.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made