Yellowstone Park Mammoth, Wyoming climate: Climate normals at a NOAA weather station
Yellowstone Park Mammoth's normal year runs from 12°F December nights to 81°F July afternoons, with 14.8 inches of precipitation and 72 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.9°C, December lows of −11°C, July highs of 27°C, 376 mm of precipitation a year.
- NOAA stationYellowstone Park Mammoth
- Station IDUSC00489905
- Location44.98°N 110.70°W
- Elevation6,195 ft (1,888 m)
On October 23, the normal high in Yellowstone Park Mammoth is 50°F and the normal low 27°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Yellowstone Park Mammoth.
- Jan 31° 12°
- Feb 34° 12°
- Mar 42° 19°
- Apr 50° 26°
- May 60° 35°
- Jun 70° 42°
- Jul 81° 48°
- Aug 80° 47°
- Sep 69° 39°
- Oct 54° 29°
- Nov 39° 19°
- Dec 30° 12°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Yellowstone Park Mammoth each month?
July is the warmest month, with normal highs of 81°F; December the coldest, with normal lows of 12°F. The most precipitation falls in June (1.86 in), the least in February (0.79 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 12°F | 21.7°F | 0.91 | 11.5 | 11 | <1 | 31 | 9 h 10 min |
| February | 34°F | 12°F | 23.3°F | 0.79 | 11.5 | 11 | <1 | 27 | 10 h 20 min |
| March | 42°F | 19°F | 30.5°F | 1.09 | 10.9 | 11 | <1 | 29 | 11 h 50 min |
| April | 50°F | 26°F | 38.0°F | 1.40 | 7.8 | 11 | <1 | 23 | 13 h 30 min |
| May | 60°F | 35°F | 47.1°F | 1.82 | 1.7 | 13 | <1 | 10 | 14 h 50 min |
| June | 70°F | 42°F | 55.8°F | 1.86 | 0.3 | 13 | <1 | 1 | 15 h 40 min |
| July | 81°F | 48°F | 64.6°F | 1.27 | 0.0 | 9 | 3 | <1 | 15 h 20 min |
| August | 80°F | 47°F | 63.1°F | 1.05 | 0.0 | 9 | 2 | <1 | 14 h 10 min |
| September | 69°F | 39°F | 53.9°F | 1.21 | 0.6 | 9 | <1 | 5 | 12 h 40 min |
| October | 54°F | 29°F | 41.3°F | 1.34 | 4.7 | 10 | <1 | 19 | 11 h |
| November | 39°F | 19°F | 29.3°F | 1.15 | 9.9 | 10 | <1 | 27 | 9 h 40 min |
| December | 30°F | 12°F | 21.1°F | 0.91 | 12.6 | 12 | <1 | 30 | 8 h 50 min |
| Year (annual) | 53°F | 28°F | 40.8°F | 14.80 | 71.5 | 127 | 6 | 202 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −11°C | −5.7°C | 23 mm | 29 cm |
| February | 1°C | −11°C | −4.8°C | 20 mm | 29 cm |
| March | 5°C | −7°C | −0.8°C | 28 mm | 28 cm |
| April | 10°C | −3°C | 3.3°C | 36 mm | 20 cm |
| May | 15°C | 1°C | 8.4°C | 46 mm | 4 cm |
| June | 21°C | 6°C | 13.2°C | 47 mm | 1 cm |
| July | 27°C | 9°C | 18.1°C | 32 mm | 0 cm |
| August | 27°C | 8°C | 17.3°C | 27 mm | 0 cm |
| September | 20°C | 4°C | 12.2°C | 31 mm | 2 cm |
| October | 12°C | −2°C | 5.2°C | 34 mm | 12 cm |
| November | 4°C | −7°C | −1.5°C | 29 mm | 25 cm |
| December | −1°C | −11°C | −6.1°C | 23 mm | 32 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00489905; 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.
Which months are mildest at Yellowstone Park Mammoth?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, August has the fewest days with rain (9).
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 USC00489905.
When is the last frost at Yellowstone Park Mammoth?
In Yellowstone Park Mammoth, the last spring frost (32°F) comes after June 3 in half of years and after June 19 in one year in ten; the first autumn frost comes before September 14 in half of years and before August 31 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 31 year in 10 after June 19; 9 in 10 after May 18
- First autumn frost, half of years before
- September 141 year in 10 before August 31; 9 in 10 before September 30
NOAA puts the median frost-free season at 102 days, and the season without a hard freeze (28°F) at 133 days.
A hard freeze (28°F) comes after May 16 in half of springs and before September 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Yellowstone Park Mammoth in zone 4b in ZIP code 59030, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 5a: the coldest night of a typical year reaches −18°F (28 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00489905; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 at Yellowstone Park Mammoth?
In a normal year in Yellowstone Park Mammoth, 6 days a year reach 90°F, 202 nights fall to 32°F or colder and 127 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 202a normal year
- Days that stay below freezing
- 57high of 32°F or less
- Days with 0.01 inch of precipitation
- 127a normal year
- Days with 1 inch of snow or more
- 29a normal year
The highest temperature in this station's record (since 1894) is 99°F, on July 15, 2002; the lowest is −36°F, on January 29, 1951.
The wettest calendar year on that record is 1947, with 20.34 in; the snowiest season is 2018–19, with 113.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00489905; records: ACIS (NOAA Regional Climate Centers), station USC00489905. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Yellowstone Park Mammoth?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds at Yellowstone Park Mammoth, 4.2 kWh per square metre a day. July is the sunniest month (85%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.7 |
| February | 67% | 2.6 |
| March | 67% | 3.8 |
| April | 69% | 5.2 |
| May | 67% | 5.8 |
| June | 74% | 6.7 |
| July | 85% | 7.3 |
| August | 82% | 6.1 |
| September | 78% | 4.7 |
| October | 66% | 2.9 |
| November | 61% | 1.8 |
| December | 58% | 1.3 |
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 many heating and cooling degree days does Yellowstone Park Mammoth record?
A normal year at Yellowstone Park Mammoth brings 8,924 heating degree days, 66% more than the median U.S. place (5,373), and 126 cooling degree days, 86% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,335 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,344 | 0 |
| February | 1,169 | 0 |
| March | 1,070 | 0 |
| April | 810 | 0 |
| May | 555 | 0 |
| June | 287 | 9 |
| July | 80 | 66 |
| August | 103 | 46 |
| September | 338 | 5 |
| October | 736 | 0 |
| November | 1,071 | 0 |
| December | 1,361 | 0 |
| Year (annual) | 8,924 | 126 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00489905. 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.
Have recent years at Yellowstone Park Mammoth been warmer than normal?
2024 averaged 42.5°F, 1.7°F above the 1991-2020 normal of 40.8°F. 1 of the 2 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2022 | 39.2°F | −1.6°F | 20.16 | – |
| 2024 | 42.5°F | +1.7°F | 12.61 | 82.3 |
Over 99 complete years from 1887 to 2024, the station's annual mean temperature rose at a fitted 0.1°F per century (+0.00°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00489905; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Yellowstone Park Mammoth's climate compare?
Yellowstone Park Mammoth is warmer than 17 of the 71 places with their own NOAA record in Wyoming, and wetter than 42. Across the 7,247 U.S. stations with normals, its annual mean of 40.8°F is warmer than 7%.
In the Köppen classification computed from these normals, Yellowstone Park Mammoth 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 Yellowstone Park Mammoth 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.
- Pray, MT1,018 people · 31 mi N
- Emigrant, MT387 people · 28 mi N
- South Glastonbury, MT263 people · 24 mi N
- Corwin Springs, MT177 people · 12 mi NW
- Jardine, MT63 people · 7 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 Yellowstone Park Mammoth's climate
What is the coldest month at Yellowstone Park Mammoth?
December, with a normal high of 30°F and a normal low of 12°F. The warmest is July (81°F by day, 48°F at night).
Does it snow at Yellowstone Park Mammoth?
Yes: 72 inches in a normal year, falling on 53 days with 0.1 inch or more, the most in December (12.6 inches).
What is the rainiest month at Yellowstone Park Mammoth?
June, with 1.86 in of precipitation in a normal year; the driest is February with 0.79 in.
What plant hardiness zone is Yellowstone Park Mammoth in?
The USDA's 2023 map puts Yellowstone Park Mammoth in zone 4b in ZIP code 59030, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −18°F (28 years, 1991-2020): zone 5a.
How late can frost come at Yellowstone Park Mammoth?
In half of years the last 32°F night comes after June 3; in one year in ten it comes after June 19. Waiting until June 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Gardiner, MT4 miles from this station, 46.3°F a year
- Tower Falls, WY14 miles from this station, 36.9°F a year
- Lamar Ranger Station, WY23 miles from this station, 37.3°F a year
- West Yellowstone, MT29 miles from this station, 35.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made