Afton, WY Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from Afton's primary NOAA station, AFTON.
The climate verdict for Afton
Dryness leads the climate profile for Afton, Wyoming, with 17.7 inches of precipitation a year. NOAA records an annual average of 39°F. At 34/100 (below average) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 2% of scores.
- 39°F
- yearly average temperature, NOAA normal
- 34/100
- comfort score, above 2% of station-mapped location scores
- 17.7"
- annual precipitation · 88" snow
- 73 days
- frost-free days per growing season
Afton: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00480027 · Afton, WY 39°F mean · 17.7" precip
TEMP-COLD · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COLD 39°F
- RANK-COOL #274
- PHOTO-FINISH ≈ Rainier Paradis…
- PRCP-DRY 17.7"
- SWING-WIDE 47°F
- COMF-LOW 34/100
- LOAD-HEAT 9,688 HDD
- STN-1 USC00480027
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Rainier Paradise Ranger Station, WA ( -0.1 °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.
- Afton (this station) 39°F
- Hot Sage, WY 39°F
- Cold Rainier Paradis…, WA 38°F
- Near Cooper Lake Pro…, AK 38°F
- Near Fossil Butte, WY 38°F
Afton 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 · Afton
Afton: 8/100 · grade F
Afton publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Afton, not an official NOAA rating. Rankings still use Comfort Score 34/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 17.7 in · 17.3 from 35 in | 39/100 · F |
| Snowfall burden | 87.8 inches/year | 3/100 · F |
| Annual temperature balance | 38.5°F · 29.0° from 67.5°F | 1/100 · F |
| Normal heat + freeze calendar | 230 calendar days | 1/100 · F |
| Frost-free season | 73 days/year | 0/100 · F |
Afton · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Afton is a continental Köppen climate: Dfb
Coldest-month mean 15.3°F and warmest-month mean 62.0°F place this station in continental, no dry season, warm summer climates (Dfb). Class Dfb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, warm summer.
- Köppen code
- Dfb
- Group
- Continental
- Warmest month
- 62.0°F
- Coldest month
- 15.3°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 Afton sits across the climate record
Three NOAA fields for Afton's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 96%
- Among 6,861 stations, Afton sits in the cooler third of annual means.
- Annual precipitation
- Drier than 76%
- Afton's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 67th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Afton compares across U.S. station-mapped locations
Afton's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
34 2nd percentile score exceeds 2% 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%). This entry sits in this band.
- 40–50: 1,113 station-mapped locations (18%). Above this entry.
- 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
Afton's measured station temperature trend
MethodologyAcross 35 complete annual observations from 1958 to 2025, AFTON warmed at a fitted rate of 0.14°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Afton primary station fitted change +0.14 °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 | 26°F (-4°C) | 5°F (-15°C) | 15°F (-9°C) | 1.3" | 21.8" | 30.8 | 0.0 |
| February | 31°F (-1°C) | 8°F (-14°C) | 19°F (-7°C) | 1.3" | 15.0" | 27.8 | 0.0 |
| March | 40°F (5°C) | 17°F (-9°C) | 28°F (-2°C) | 1.5" | 12.2" | 30.1 | 0.0 |
| April | 50°F (10°C) | 25°F (-4°C) | 38°F (3°C) | 1.5" | 5.0" | 26.4 | 0.0 |
| May | 60°F (16°C) | 33°F (1°C) | 47°F (8°C) | 2.4" | 0.8" | 12.6 | 0.0 |
| June | 71°F (21°C) | 38°F (4°C) | 55°F (13°C) | 1.8" | 0.2" | 3.5 | 0.2 |
| July | 80°F (27°C) | 44°F (7°C) | 62°F (17°C) | 1.1" | 0.0" | 0.5 | 2.6 |
| August | 79°F (26°C) | 43°F (6°C) | 61°F (16°C) | 1.1" | 0.0" | 1.1 | 2.0 |
| September | 69°F (21°C) | 34°F (1°C) | 52°F (11°C) | 1.5" | 0.2" | 9.3 | 0.0 |
| October | 56°F (13°C) | 26°F (-4°C) | 41°F (5°C) | 1.6" | 3.7" | 25.4 | 0.0 |
| November | 39°F (4°C) | 16°F (-9°C) | 28°F (-2°C) | 1.3" | 11.4" | 28.7 | 0.0 |
| December | 27°F (-3°C) | 7°F (-14°C) | 17°F (-8°C) | 1.4" | 17.5" | 30.5 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 82°F around July 27, short of 90°F on every date, while 230 dates carry a normal low at or below freezing, the coldest 4°F near January 1.
The freezing stretch
The normal low stays at or below 32°F into May 10, then returns to freezing around September 24, covering 230 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 December 21, when 41% of years recorded at least a hundredth of an inch. The driest is August 17 at 18%. Summed across the calendar, that is about 111 wet dates a year.
The widest day
August 13 carries the biggest normal gap between afternoon and dawn, 37°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Afton.
Where Afton Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 230 nights a year, placing this among the most frost-prone tenth of ranked stations.
Day-to-night contrast is extreme by national standards — the widest normal daily swing reaches about 37°F, sharper than nine in ten ranked stations see.
Afton earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 21.8"
11.8 days with precipitation
Snow: 15.0"
10.7 days with precipitation
Snow: 12.2"
9.3 days with precipitation
Snow: 5.0"
9.7 days with precipitation
Snow: 0.8"
11.0 days with precipitation
Snow: 0.2"
8.2 days with precipitation
6.5 days with precipitation
5.7 days with precipitation
Snow: 0.2"
7.1 days with precipitation
Snow: 3.7"
8.5 days with precipitation
Snow: 11.4"
9.5 days with precipitation
Snow: 17.5"
12.5 days with precipitation
Afton spreads its precipitation across the year
Neither half of the year dominates here: June through August take 22% of the annual total and December through February 22%, with neither reaching the 35% that would mark a distinct wet season. Afton has no dry season to plan around, though it does carry a wide 46.7°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: May averages 2.4" and July 1.1". The three wettest months together take 33% 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.
Afton is dry, and what does fall arrives gently
Only about 111 days a year record measurable precipitation here, 30% of the calendar, and they carry 17.7" 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 December at about 13 wet days; the driest is August at about 6.
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 Afton
Afton averages 87.8 inches of snowfall a year, with January the snowiest month on the normals, spread across roughly 50 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: 87.8 inches of depth.
- Days recording measurable snow: about 50 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 50% 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
September 1
50% probability date
Last Spring Freeze
June 20
50% probability date
Growing Season
73 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
9,688
Higher = more heating needed
Cooling Degree Days
41
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside WY closest to Afton 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 (39°F here).
- Kremmling, CO 39°F · 0.0°F off
- Baudette, MN 38°F · 0.1°F off
- Bottineau, ND 39°F · 0.1°F off
- Floodwood, MN 38°F · 0.1°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (17.7" here), excluding temperature-peer places.
- Hart, TX 17.7" · 0.0" off
- Jerome, AZ 17.7" · 0.0" off
- Dumas, TX 17.7" · 0.0" off
- Mccarthy, AK 17.7" · 0.0" off
Snow and freeze rhythm
When cold and snow define Afton
heating led · dry · mid swing
Afton's energy balance leans toward cold weather: 9,688 annual heating degree days against 41 for cooling. Its 46.7°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 73 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.
-
1. Afton coldest normal
January
Averaging 15°F (-9°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Afton typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Afton snow peak
January
Afton averages 87.8 inches of snow a year, with January the snowiest month on the normals.
Questions about Afton's climate
How much snow does Afton get? ▼
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Afton's primary station: AFTON (USC00480027). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 5600245). Match rule for Afton: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Afton 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.