Dayton, Wyoming climate: Normal weather by month, frost dates and records
Dayton's normal year runs from 10°F December nights to 85°F July afternoons, with 18.0 inches of precipitation and 68 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.6°C, December lows of −12°C, July highs of 30°C, 458 mm of precipitation a year.
- NOAA stationDayton
- Station IDUSC00482399
- Location44.88°N 107.26°W
- Elevation3,920 ft (1,195 m)
- Population829
On October 22, the normal high in Dayton is 56°F and the normal low 28°F, and the chance of measurable rain or snow is 26%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Dayton.
- Jan 36° 10°
- Feb 38° 12°
- Mar 47° 20°
- Apr 55° 29°
- May 65° 38°
- Jun 75° 45°
- Jul 85° 51°
- Aug 84° 50°
- Sep 73° 40°
- Oct 59° 30°
- Nov 46° 18°
- Dec 36° 10°
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 Dayton each month?
July is the warmest month, with normal highs of 85°F; December the coldest, with normal lows of 10°F. The most precipitation falls in May (3.36 in), the least in January (0.82 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 10°F | 23.1°F | 0.82 | 10.8 | 7 | <1 | 30 | 9 h 10 min |
| February | 38°F | 12°F | 25.0°F | 0.89 | 11.1 | 7 | <1 | 28 | 10 h 20 min |
| March | 47°F | 20°F | 33.5°F | 1.49 | 12.0 | 8 | <1 | 28 | 11 h 50 min |
| April | 55°F | 29°F | 42.1°F | 2.06 | 7.1 | 10 | <1 | 23 | 13 h 30 min |
| May | 65°F | 38°F | 51.3°F | 3.36 | 1.4 | 11 | <1 | 8 | 14 h 50 min |
| June | 75°F | 45°F | 60.1°F | 1.99 | 0.0 | 10 | 2 | 1 | 15 h 30 min |
| July | 85°F | 51°F | 68.2°F | 1.16 | 0.0 | 7 | 11 | <1 | 15 h 20 min |
| August | 84°F | 50°F | 67.0°F | 0.88 | 0.0 | 6 | 8 | <1 | 14 h 10 min |
| September | 73°F | 40°F | 56.8°F | 1.55 | 0.3 | 7 | 2 | 4 | 12 h 40 min |
| October | 59°F | 30°F | 44.5°F | 1.86 | 6.4 | 9 | <1 | 20 | 11 h |
| November | 46°F | 18°F | 31.9°F | 1.15 | 7.5 | 7 | <1 | 28 | 9 h 40 min |
| December | 36°F | 10°F | 22.9°F | 0.82 | 11.7 | 7 | <1 | 31 | 8 h 50 min |
| Year (annual) | 58°F | 29°F | 43.9°F | 18.03 | 68.3 | 94 | 24 | 197 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −12°C | −4.9°C | 21 mm | 27 cm |
| February | 3°C | −11°C | −3.9°C | 23 mm | 28 cm |
| March | 8°C | −7°C | 0.8°C | 38 mm | 30 cm |
| April | 13°C | −2°C | 5.6°C | 52 mm | 18 cm |
| May | 18°C | 3°C | 10.7°C | 85 mm | 4 cm |
| June | 24°C | 7°C | 15.6°C | 51 mm | 0 cm |
| July | 30°C | 11°C | 20.1°C | 29 mm | 0 cm |
| August | 29°C | 10°C | 19.4°C | 22 mm | 0 cm |
| September | 23°C | 5°C | 13.8°C | 39 mm | 1 cm |
| October | 15°C | −1°C | 6.9°C | 47 mm | 16 cm |
| November | 8°C | −8°C | −0.1°C | 29 mm | 19 cm |
| December | 2°C | −12°C | −5.1°C | 21 mm | 30 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00482399; 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 Dayton?
Normal highs sit between 65°F and 85°F in May, June, 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 USC00482399.
When is the last frost in Dayton?
In Dayton, the last spring frost (32°F) comes after May 24 in half of years and after June 7 in one year in ten; the first autumn frost comes before September 18 in half of years and before September 2 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 241 year in 10 after June 7; 9 in 10 after May 11
- First autumn frost, half of years before
- September 181 year in 10 before September 2; 9 in 10 before October 2
NOAA puts the median frost-free season at 114 days, and the season without a hard freeze (28°F) at 140 days.
A hard freeze (28°F) comes after May 9 in half of springs and before September 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Dayton in zone 5a in ZIP code 82844, 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 USC00482399; 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 Dayton?
In a normal year in Dayton, 24 days a year reach 90°F (1 of them 100°F or more), 197 nights fall to 32°F or colder and 94 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 197a normal year
- Days that stay below freezing
- 44high of 32°F or less
- Days with 0.01 inch of precipitation
- 94a normal year
- Days with 1 inch of snow or more
- 25a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00482399.
How sunny is Dayton?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Dayton, 4.4 kWh per square metre a day. July is the sunniest month (87%) and April the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.0 |
| February | 76% | 3.0 |
| March | 73% | 4.0 |
| April | 69% | 5.0 |
| May | 70% | 5.9 |
| June | 81% | 7.2 |
| July | 87% | 7.3 |
| August | 86% | 6.2 |
| September | 83% | 4.9 |
| October | 74% | 3.1 |
| November | 72% | 2.0 |
| December | 70% | 1.6 |
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 Dayton need?
A normal year in Dayton brings 7,972 heating degree days, 48% more than the median U.S. place (5,373), and 294 cooling degree days, 68% 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 1,854 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,300 | 0 |
| February | 1,119 | 0 |
| March | 977 | 0 |
| April | 689 | 0 |
| May | 427 | 4 |
| June | 170 | 21 |
| July | 31 | 130 |
| August | 56 | 118 |
| September | 266 | 19 |
| October | 637 | 2 |
| November | 993 | 0 |
| December | 1,306 | 0 |
| Year (annual) | 7,972 | 294 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00482399. 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 Dayton been warmer than normal lately?
2025 averaged 46.3°F, 2.4°F above the 1991-2020 normal of 43.9°F. 2 of the 2 complete years since 2023 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2023 | 47.5°F | +3.6°F | 22.04 | 80.8 |
| 2025 | 46.3°F | +2.4°F | – | – |
Source: observed years: ACIS, station USC00482399. A year counts only with all twelve months complete.
How does Dayton's climate compare?
Dayton is warmer than 32 of the other 70 places with their own NOAA record in Wyoming, and wetter than 55. Across the 7,247 U.S. stations with normals, its annual mean of 43.9°F is warmer than 15%.
In the Köppen classification computed from these normals, Dayton 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 Dayton share this climate record?
Ranchester has no NOAA station with 1991-2020 normals of its 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.
- Ranchester, WY1,176 people · 5 mi NE
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 Dayton's climate
What is the coldest month in Dayton?
December, with a normal high of 36°F and a normal low of 10°F. The warmest is July (85°F by day, 51°F at night).
Does it snow in Dayton?
Yes: 68 inches in a normal year, falling on 32 days with 0.1 inch or more, the most in March (12.0 inches).
What is the rainiest month in Dayton?
May, with 3.36 in of precipitation in a normal year; the driest is January with 0.82 in.
What plant hardiness zone is Dayton in?
The USDA's 2023 map puts Dayton in zone 5a in ZIP code 82844, the nearest ZIP area.
How late can frost come in Dayton?
In half of years the last 32°F night comes after May 24; in one year in ten it comes after June 7. Waiting until June 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
- Burgess Junction, WY14 miles from this station, 34.5°F a year
- Sheridan, WY16 miles from this station, 45.4°F a year
- Big Horn, WY18 miles from this station, 45.5°F a year
- Wyola, MT18 miles from this station, 46.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made