Casper Wwtp, WY Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Casper Wwtp's primary NOAA station, CASPER WWTP.
The climate verdict for Casper Wwtp
Dryness leads the climate profile for Casper Wwtp, Wyoming, with 13.4 inches of precipitation a year. NOAA records an annual average of 47°F. At 52/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 24% of scores.
- 47°F
- average temperature, NOAA 1991-2020 normal
- 52/100
- comfort score, above 24% of station-mapped location scores
- 13.4"
- precipitation, annual total
- 142 days
- frost-free growing season
Casper Wwtp: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00481569 · Casper Wwtp, WY 47°F mean · 13.4" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 47°F
- RANK-COOL #1,990
- PHOTO-FINISH ≈ Lapeer Wwtp
- PRCP-DRY 13.4"
- SWING-WIDE 45°F
- COMF-LOW 52/100
- LOAD-HEAT 6,956 HDD
- STN-1 USC00481569
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Lapeer Wwtp, MI (+ 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.
- Casper Wwtp (this station) 47°F
- Cold Charlotte, MI 47°F
- Hot Harrisburg, NE 47°F
- Near Lapeer Wwtp, MI 47°F
- Near Leverett, MA 47°F
Casper Wwtp 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 · Casper Wwtp
Casper Wwtp: 24/100 · grade F
Casper Wwtp publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Casper Wwtp, not an official NOAA rating. Rankings still use Comfort Score 52/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 47.4°F · 20.1° from 67.5°F | 29/100 · F |
| Precipitation balance | 13.4 in · 21.6 from 35 in | 23/100 · F |
| Normal heat + freeze calendar | 188 calendar days | 21/100 · F |
| Frost-free season | 142 days/year | 20/100 · F |
Casper Wwtp · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Casper Wwtp is a continental Köppen climate: Dfa
Coldest-month mean 27.3°F and warmest-month mean 72.3°F place this station in continental, no dry season, hot summer climates (Dfa). Class Dfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, hot summer.
- Köppen code
- Dfa
- Group
- Continental
- Warmest month
- 72.3°F
- Coldest month
- 27.3°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 Casper Wwtp sits across the climate record
Three NOAA fields for Casper Wwtp's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 71%
- Among 6,861 stations, Casper Wwtp sits in the cooler third of annual means.
- Annual precipitation
- Drier than 86%
- Casper Wwtp's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 59th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Casper Wwtp compares across U.S. station-mapped locations
Casper Wwtp's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
52 24th percentile score exceeds 24% 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%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). This entry sits in this band.
- 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
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 38°F (3°C) | 17°F (-9°C) | 27°F (-3°C) | 0.4" | 27.5 | 0.0 |
| February | 40°F (4°C) | 18°F (-8°C) | 29°F (-2°C) | 0.6" | 25.4 | 0.0 |
| March | 49°F (9°C) | 25°F (-4°C) | 37°F (3°C) | 1.0" | 24.3 | 0.0 |
| April | 57°F (14°C) | 31°F (-1°C) | 44°F (7°C) | 1.5" | 17.1 | 0.0 |
| May | 67°F (19°C) | 41°F (5°C) | 54°F (12°C) | 2.7" | 4.4 | 0.3 |
| June | 79°F (26°C) | 50°F (10°C) | 64°F (18°C) | 1.6" | 0.1 | 5.4 |
| July | 88°F (31°C) | 56°F (14°C) | 72°F (22°C) | 1.2" | 0.0 | 16.4 |
| August | 87°F (30°C) | 55°F (13°C) | 71°F (22°C) | 1.0" | 0.0 | 11.6 |
| September | 76°F (24°C) | 44°F (7°C) | 60°F (16°C) | 1.1" | 1.3 | 2.0 |
| October | 61°F (16°C) | 33°F (1°C) | 47°F (8°C) | 1.3" | 13.0 | 0.0 |
| November | 48°F (9°C) | 25°F (-4°C) | 36°F (2°C) | 0.5" | 22.5 | 0.0 |
| December | 38°F (3°C) | 17°F (-8°C) | 28°F (-2°C) | 0.7" | 27.0 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 90°F around July 24, short of 90°F on every date, while 188 dates carry a normal low at or below freezing, the coldest 16°F near December 28.
The freezing stretch
The normal low stays at or below 32°F into April 23, then returns to freezing around October 19, covering 188 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 10, when 31% of years recorded at least a hundredth of an inch. The driest is November 20 at 15%. Summed across the calendar, that is about 72 wet dates a year.
The widest day
September 6 carries the biggest normal gap between afternoon and dawn, 33°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Casper Wwtp.
Where Casper Wwtp Stands Nationally
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 188 nights a year, more than most ranked stations.
A drier-than-most normal water year — around 13 inches, below what four out of five ranked stations collect.
Casper Wwtp earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
4.8 days with precipitation
4.9 days with precipitation
5.2 days with precipitation
7.7 days with precipitation
9.6 days with precipitation
6.8 days with precipitation
6.4 days with precipitation
5.6 days with precipitation
6.2 days with precipitation
5.8 days with precipitation
4.3 days with precipitation
5.0 days with precipitation
Casper Wwtp spreads its precipitation across the year
Neither half of the year dominates here: June through August take 28% of the annual total and December through February 13%, with neither reaching the 35% that would mark a distinct wet season. Casper Wwtp has no dry season to plan around, though it does carry a wide 45°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: May averages 2.7" and January 0.4". The three wettest months together take 43% 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.
Casper Wwtp is dry, and what does fall arrives gently
Only about 72 days a year record measurable precipitation here, 20% of the calendar, and they carry 13.4" between them. At roughly 0.19 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 10 wet days; the driest is November at about 4.
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.
Frost Dates & Growing Season
First Fall Freeze
September 29
50% probability date
Last Spring Freeze
May 10
50% probability date
Growing Season
142 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,956
Higher = more heating needed
Cooling Degree Days
564
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside WY closest to Casper Wwtp 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 (47°F here).
- Allegan, MI 47°F · 0.0°F off
- Auburn, NY 47°F · 0.0°F off
- Bartow, WV 47°F · 0.0°F off
- Biddle, MT 47°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (13.4" here), excluding temperature-peer places.
- Briggsdale, CO 13.4" · 0.0" off
- Chinook, MT 13.4" · 0.0" off
- Glasgow, MT 13.4" · 0.0" off
- Stockton, CA 13.4" · 0.0" off
Scarce-water calendar
Where Casper Wwtp's limited precipitation lands
heating led · dry · mid swing
Casper Wwtp's energy balance leans toward cold weather: 6,956 annual heating degree days against 564 for cooling. Its 45.0°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 142 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
July and January mark the typical warm and cold ends of the calendar in Casper Wwtp's middle-range seasonal profile. The measured spread is 45.0°F. The annual average is 47°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Casper Wwtp's cold-season load does not imply a wet climate. Annual precipitation is 13.4 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
Casper Wwtp wettest normal
May
May concentrates the scarce annual total (13.4 inches).
Casper Wwtp driest normal
January
January is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Casper Wwtp's climate
How dry is Casper Wwtp? ▼
How many days above 90°F does Casper Wwtp get? ▼
How much energy does heating and cooling require in Casper Wwtp? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Casper Wwtp's primary station: CASPER WWTP (USC00481569). 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 Casper Wwtp; 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 Casper Wwtp 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.