Afton, Wyoming climate: Normal weather by month, frost dates and records
Afton's normal year runs from 5°F January nights to 80°F July afternoons, with 17.7 inches of precipitation and 88 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 3.6°C, January lows of −15°C, July highs of 27°C, 450 mm of precipitation a year.
- NOAA stationAfton
- Station IDUSC00480027
- Location42.73°N 110.92°W
- Elevation6,248 ft (1,904 m)
- Population2,280
On October 23, the normal high in Afton is 52°F and the normal low 24°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Afton.
- Jan 26° 5°
- Feb 31° 8°
- Mar 40° 17°
- Apr 50° 25°
- May 60° 33°
- Jun 71° 38°
- Jul 80° 44°
- Aug 79° 43°
- Sep 69° 34°
- Oct 56° 26°
- Nov 39° 16°
- Dec 27° 7°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Afton each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 5°F. The most precipitation falls in May (2.36 in), the least in July (1.05 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 26°F | 5°F | 15.3°F | 1.25 | 21.8 | 12 | <1 | 31 | 9 h 20 min |
| February | 31°F | 8°F | 19.1°F | 1.31 | 15.0 | 11 | <1 | 28 | 10 h 30 min |
| March | 40°F | 17°F | 28.4°F | 1.47 | 12.2 | 9 | <1 | 30 | 11 h 50 min |
| April | 50°F | 25°F | 37.5°F | 1.46 | 5.0 | 10 | <1 | 26 | 13 h 20 min |
| May | 60°F | 33°F | 46.7°F | 2.36 | 0.8 | 11 | <1 | 13 | 14 h 40 min |
| June | 71°F | 38°F | 54.5°F | 1.82 | 0.2 | 8 | <1 | 4 | 15 h 20 min |
| July | 80°F | 44°F | 62.0°F | 1.05 | 0.0 | 7 | 3 | 1 | 15 h |
| August | 79°F | 43°F | 61.0°F | 1.11 | 0.0 | 6 | 2 | 1 | 14 h |
| September | 69°F | 34°F | 51.9°F | 1.52 | 0.2 | 7 | <1 | 9 | 12 h 30 min |
| October | 56°F | 26°F | 40.7°F | 1.63 | 3.7 | 9 | <1 | 25 | 11 h 10 min |
| November | 39°F | 16°F | 27.8°F | 1.34 | 11.4 | 10 | <1 | 29 | 9 h 50 min |
| December | 27°F | 7°F | 16.8°F | 1.41 | 17.5 | 13 | <1 | 31 | 9 h |
| Year (annual) | 52°F | 25°F | 38.5°F | 17.73 | 87.8 | 111 | 5 | 227 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −4°C | −15°C | −9.3°C | 32 mm | 55 cm |
| February | −1°C | −14°C | −7.2°C | 33 mm | 38 cm |
| March | 5°C | −9°C | −2.0°C | 37 mm | 31 cm |
| April | 10°C | −4°C | 3.1°C | 37 mm | 13 cm |
| May | 16°C | 1°C | 8.2°C | 60 mm | 2 cm |
| June | 21°C | 4°C | 12.5°C | 46 mm | 1 cm |
| July | 27°C | 7°C | 16.7°C | 27 mm | 0 cm |
| August | 26°C | 6°C | 16.1°C | 28 mm | 0 cm |
| September | 21°C | 1°C | 11.1°C | 39 mm | 1 cm |
| October | 13°C | −4°C | 4.8°C | 41 mm | 9 cm |
| November | 4°C | −9°C | −2.3°C | 34 mm | 29 cm |
| December | −3°C | −14°C | −8.4°C | 36 mm | 44 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00480027; 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.
When is the best weather to visit Afton?
Normal highs sit between 65°F and 85°F in June, July, 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 USC00480027.
When is the last frost in Afton?
In Afton, the last spring frost (32°F) comes after June 20 in half of years and after July 7 in one year in ten; the first autumn frost comes before September 1 in half of years and before August 12 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
- June 201 year in 10 after July 7; 9 in 10 after June 2
- First autumn frost, half of years before
- September 11 year in 10 before August 12; 9 in 10 before September 15
NOAA puts the median frost-free season at 71 days, and the season without a hard freeze (28°F) at 104 days.
A hard freeze (28°F) comes after June 1 in half of springs and before September 13 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Afton in zone 5b in ZIP code 83110, 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 USC00480027; 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 in Afton?
In a normal year in Afton, 5 days a year reach 90°F, 227 nights fall to 32°F or colder and 111 days bring measurable precipitation.
- Days at 90°F or more
- 5a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 227a normal year
- Days that stay below freezing
- 63high of 32°F or less
- Days with 0.01 inch of precipitation
- 111a normal year
- Days with 1 inch of snow or more
- 31a normal year
The highest temperature in this station's record (since 1957) is 95°F, on July 16, 1976; the lowest is −46°F, on January 1, 1979.
The wettest calendar year on that record is 2023, with 29.20 in; the snowiest season is 2022–23, with 187.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00480027; records: ACIS (NOAA Regional Climate Centers), station USC00480027. Records use complete months only; a month missing more than three days is left out.
How sunny is Afton?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Afton, 4.7 kWh per square metre a day. July is the sunniest month (86%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.2 |
| February | 74% | 3.1 |
| March | 76% | 4.5 |
| April | 75% | 5.6 |
| May | 74% | 6.3 |
| June | 83% | 7.5 |
| July | 86% | 7.5 |
| August | 85% | 6.4 |
| September | 83% | 5.1 |
| October | 77% | 3.5 |
| November | 73% | 2.3 |
| December | 70% | 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 much heating and cooling does Afton need?
A normal year in Afton brings 9,688 heating degree days, 80% more than the median U.S. place (5,373), and 41 cooling degree days, 95% fewer than the median (908). Ten months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,061 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,542 | 0 |
| February | 1,287 | 0 |
| March | 1,135 | 0 |
| April | 825 | 0 |
| May | 566 | 0 |
| June | 316 | 1 |
| July | 115 | 24 |
| August | 141 | 16 |
| September | 395 | 0 |
| October | 755 | 0 |
| November | 1,116 | 0 |
| December | 1,496 | 0 |
| Year (annual) | 9,688 | 41 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00480027. 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.
Has Afton been warmer than normal lately?
2025 averaged 41.1°F, 2.6°F above the 1991-2020 normal of 38.5°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 40.3°F | +1.8°F | 20.73 | 105.7 |
| 2022 | 36.8°F | −1.7°F | 19.49 | 116.2 |
| 2023 | 38.1°F | −0.4°F | 29.20 | 147.4 |
| 2024 | 40.6°F | +2.1°F | 19.40 | 140.3 |
| 2025 | 41.1°F | +2.6°F | 23.66 | 102.3 |
Over 35 complete years from 1958 to 2025, the station's annual mean temperature rose at a fitted 2.5°F per century (+0.14°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00480027; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Afton's climate compare?
Afton is warmer than 10 of the other 70 places with their own NOAA record in Wyoming, and wetter than 53. Across the 7,247 U.S. stations with normals, its annual mean of 38.5°F is warmer than 4%.
In the Köppen classification computed from these normals, Afton is Dfb: continental, no dry season, warm summer. 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.
Which places near Afton share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Osmond, WY1,270 people · 4 mi S
- Grover, WY1,046 people · 5 mi N
- Smoot, WY745 people · 8 mi S
- Auburn, WY286 people · 7 mi NW
- Fairview, WY97 people · 5 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Afton's climate
What is the coldest month in Afton?
January, with a normal high of 26°F and a normal low of 5°F. The warmest is July (80°F by day, 44°F at night).
Does it snow in Afton?
Yes: 88 inches in a normal year, falling on 50 days with 0.1 inch or more, the most in January (21.8 inches).
What is the rainiest month in Afton?
May, with 2.36 in of precipitation in a normal year; the driest is July with 1.05 in.
What plant hardiness zone is Afton in?
The USDA's 2023 map puts Afton in zone 5b in ZIP code 83110, the nearest ZIP area.
How late can frost come in Afton?
In half of years the last 32°F night comes after June 20; in one year in ten it comes after July 7. Waiting until July 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Bedford, WY10 miles from this station, 38.6°F a year
- Soda Springs, ID34 miles from this station, 42.4°F a year
- Bern, ID36 miles from this station, 41.1°F a year
- Bondurant, WY42 miles from this station, 37.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made