Boysen Dam, WY Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Boysen Dam's primary NOAA station, BOYSEN DAM.
The climate verdict for Boysen Dam
Winter sets the terms in Boysen Dam, Wyoming. A pronounced 57.6°F seasonal swing and heating demand above twice the cooling total frame an annual average of 46°F. At 44/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 10% of scores.
- 46°F
- yearly average temperature, NOAA normal
- 44/100
- comfort score, above 10% of station-mapped location scores
- 9.0"
- annual precipitation · 16" snow
- 155 days
- frost-free growing season
Boysen Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00481000 · Boysen Dam, WY 46°F mean · 9.0" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-ARID · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 46°F
- RANK-COOL #1,715
- PHOTO-FINISH ≈ Bridgewater
- PRCP-ARID 9.0"
- SWING-WIDE 58°F
- COMF-LOW 44/100
- LOAD-HEAT 7,515 HDD
- STN-1 USC00481000
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Bridgewater, SD (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every WY station list.
- Boysen Dam (this station) 46°F
- Cold Greybull S Big…, WY 46°F
- Hot Centerville, SD 46°F
- Near Bridgewater, SD 46°F
- Near Minnesota City…, MN 46°F
Boysen Dam sits in Wyoming, the #5 coldest U.S. state at 43.3°F statewide annual average - see all 50 coldest states ranked by NOAA normals
Climate Living Index · Boysen Dam
Boysen Dam: 22/100 · grade F
Boysen Dam publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Boysen Dam, not an official NOAA rating. Rankings still use Comfort Score 44/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Snowfall burden | 16.1 inches/year | 54/100 · D |
| Frost-free season | 155 days/year | 29/100 · F |
| Annual temperature balance | 46.4°F · 21.1° from 67.5°F | 25/100 · F |
| Normal heat + freeze calendar | 208 calendar days | 10/100 · F |
| Precipitation balance | 9.0 in · 26.0 from 35 in | 9/100 · F |
Boysen Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Boysen Dam's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 75.1°F
- Coldest month
- 17.5°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Boysen Dam sits across the climate record
Three NOAA fields for Boysen Dam's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 75%
- Among 6,861 stations, Boysen Dam sits in the cooler third of annual means.
- Annual precipitation
- Drier than 95%
- Boysen Dam's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 95%
- Warmest-to-coldest month gap for Boysen Dam is large versus 6,861 complete station-years.
How Boysen Dam compares across U.S. station-mapped locations
Boysen Dam's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
44 10th percentile score exceeds 10% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Boysen Dam's measured station temperature trend
MethodologyAcross 47 complete annual observations from 1950 to 2025, BOYSEN DAM warmed at a fitted rate of 0.10°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Boysen Dam primary station fitted change +0.10 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 30°F (-1°C) | 5°F (-15°C) | 18°F (-8°C) | 0.2" | 2.8" | 30.9 | 0.0 |
| February | 37°F (3°C) | 11°F (-12°C) | 24°F (-4°C) | 0.3" | 3.2" | 27.8 | 0.0 |
| March | 50°F (10°C) | 23°F (-5°C) | 37°F (3°C) | 0.6" | 3.8" | 26.7 | 0.0 |
| April | 59°F (15°C) | 33°F (0°C) | 46°F (8°C) | 1.1" | 1.3" | 13.9 | 0.0 |
| May | 69°F (20°C) | 43°F (6°C) | 56°F (13°C) | 2.1" | 0.1" | 2.5 | 0.5 |
| June | 81°F (27°C) | 52°F (11°C) | 66°F (19°C) | 1.0" | 0.0" | 0.1 | 6.3 |
| July | 91°F (33°C) | 60°F (15°C) | 75°F (24°C) | 0.8" | 0.0" | 0.0 | 20.2 |
| August | 89°F (31°C) | 57°F (14°C) | 73°F (23°C) | 0.5" | 0.0" | 0.0 | 16.9 |
| September | 77°F (25°C) | 47°F (8°C) | 62°F (17°C) | 1.0" | 0.1" | 0.5 | 2.8 |
| October | 60°F (16°C) | 35°F (1°C) | 48°F (9°C) | 0.9" | 0.8" | 11.4 | 0.0 |
| November | 44°F (7°C) | 22°F (-5°C) | 33°F (1°C) | 0.3" | 1.8" | 27.5 | 0.0 |
| December | 31°F (0°C) | 9°F (-13°C) | 20°F (-7°C) | 0.4" | 2.2" | 30.7 | 0.0 |
The year, day by day
Boysen Dam works both ends of the calendar. Normal highs climb to 92°F by July 24 and hold at or above 90°F on 33 dates, then normal lows drop to freezing or below on 175 dates, bottoming at 5°F around January 5.
When the heat sits
Normal highs reach 90°F from July 11 through August 12, covering 33 dates. The broader mild season, normal highs of 70°F or more, runs May 20 to September 28.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
The freezing stretch
The normal low stays at or below 32°F into April 13, then returns to freezing around October 22, covering 175 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is May 21, when 26% of years recorded at least a hundredth of an inch. The driest is January 13 at 10%. Summed across the calendar, that is about 56 wet dates a year.
The widest day
August 20 carries the biggest normal gap between afternoon and dawn, 31°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Boysen Dam.
Where Boysen Dam Stands Nationally
Aridity defines the water calendar: about 9 inches in a normal year lands this among the driest tenth of ranked stations.
Boysen Dam earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 2.8"
2.9 days with precipitation
Snow: 3.2"
3.5 days with precipitation
Snow: 3.8"
4.1 days with precipitation
Snow: 1.3"
5.9 days with precipitation
Snow: 0.1"
8.1 days with precipitation
5.9 days with precipitation
5.0 days with precipitation
4.1 days with precipitation
Snow: 0.1"
4.8 days with precipitation
Snow: 0.8"
4.3 days with precipitation
Snow: 1.8"
3.3 days with precipitation
Snow: 2.2"
3.7 days with precipitation
Boysen Dam spreads its precipitation across the year
Neither half of the year dominates here: June through August take 25% of the annual total and December through February 10%, with neither reaching the 35% that would mark a distinct wet season. Boysen Dam has no dry season to plan around, though it does carry a wide 57.6°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: May averages 2.1" and January 0.2". The three wettest months together take 46% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
Boysen Dam is dry, and what does fall arrives gently
Only about 56 days a year record measurable precipitation here, 15% of the calendar, and they carry 9.0" between them. At roughly 0.16 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is May at about 8 wet days; the driest is January at about 3.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Winter brings real snow to Boysen Dam
Boysen Dam averages 16.1 inches of snowfall a year, with March the snowiest month on the normals, spread across roughly 11 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 16.1 inches of depth.
- Days recording measurable snow: about 11 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 18% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 7
50% probability date
Last Spring Freeze
May 5
50% probability date
Growing Season
155 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,515
Higher = more heating needed
Cooling Degree Days
769
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside WY closest to Boysen Dam on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (46°F here).
- Bad Axe, MI 46°F · 0.0°F off
- Bickleton, WA 46°F · 0.0°F off
- Bridgewater, SD 46°F · 0.0°F off
- Camp Crook, SD 46°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (9.0" here), excluding temperature-peer places.
- San Luis, CO 9.0" · 0.0" off
- Wenatchee, WA 9.0" · 0.0" off
- Ellensburg, WA 9.0" · 0.0" off
- Wellington, UT 9.1" · 0.0" off
Snow and freeze rhythm
When cold and snow define Boysen Dam
heating led · dry · high swing
Winter and seasonal range jointly define this record. Boysen Dam logs 7,515 heating degree days, more than twice its 769 cooling total, while the typical coldest-to-warmest-month gap reaches 57.6°F. The annual mean therefore compresses two materially different seasons.
Boysen Dam's frost-free season lasts about 155 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Boysen Dam coldest normal
January
Averaging 18°F (-8°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Boysen Dam typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Boysen Dam snow peak
March
Boysen Dam averages 16.1 inches of snow a year, with March the snowiest month on the normals.
Questions about Boysen Dam's climate
How much snow does Boysen Dam get? ▼
How many days above 90°F does Boysen Dam get? ▼
How much energy does heating and cooling require in Boysen Dam? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Boysen Dam's primary station: BOYSEN DAM (USC00481000). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Boysen Dam; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Boysen Dam comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.