Jeffrey City, Wyoming climate: Normal weather by month, frost dates and records
Jeffrey City's normal year runs from 9°F January nights to 85°F July afternoons, with 9.9 inches of precipitation and 60 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.7°C, January lows of −13°C, July highs of 30°C, 251 mm of precipitation a year.
- NOAA stationJeffrey City
- Station IDUSC00484925
- Location42.49°N 107.83°W
- Elevation6,319 ft (1,926 m)
- Population (census place)0
On October 23, the normal high in Jeffrey City is 54°F and the normal low 26°F, and the chance of measurable rain or snow is 14%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Jeffrey City.
- Jan 31° 9°
- Feb 34° 11°
- Mar 45° 20°
- Apr 54° 26°
- May 64° 35°
- Jun 76° 43°
- Jul 85° 50°
- Aug 83° 48°
- Sep 73° 39°
- Oct 58° 29°
- Nov 42° 18°
- Dec 31° 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 Jeffrey City each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 9°F. The most precipitation falls in May (1.97 in), the least in January (0.35 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 9°F | 20.0°F | 0.35 | 5.0 | 3 | <1 | 31 | 9 h 20 min |
| February | 34°F | 11°F | 22.3°F | 0.50 | 7.0 | 4 | <1 | 28 | 10 h 30 min |
| March | 45°F | 20°F | 32.1°F | 0.79 | 8.8 | 4 | <1 | 28 | 11 h 50 min |
| April | 54°F | 26°F | 40.2°F | 1.40 | 12.1 | 7 | <1 | 23 | 13 h 20 min |
| May | 64°F | 35°F | 49.6°F | 1.97 | 5.6 | 9 | <1 | 11 | 14 h 30 min |
| June | 76°F | 43°F | 59.8°F | 0.97 | 0.4 | 5 | 2 | 1 | 15 h 20 min |
| July | 85°F | 50°F | 67.6°F | 0.66 | 0.0 | 4 | 8 | <1 | 15 h |
| August | 83°F | 48°F | 65.8°F | 0.54 | 0.0 | 4 | 4 | <1 | 14 h |
| September | 73°F | 39°F | 56.0°F | 0.82 | 1.3 | 5 | <1 | 7 | 12 h 30 min |
| October | 58°F | 29°F | 43.3°F | 0.91 | 7.4 | 5 | <1 | 21 | 11 h 10 min |
| November | 42°F | 18°F | 30.1°F | 0.51 | 6.3 | 3 | <1 | 27 | 9 h 50 min |
| December | 31°F | 10°F | 20.3°F | 0.46 | 6.3 | 3 | <1 | 31 | 9 h 10 min |
| Year (annual) | 56°F | 28°F | 42.3°F | 9.88 | 60.2 | 56 | 13 | 207 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −13°C | −6.7°C | 9 mm | 13 cm |
| February | 1°C | −12°C | −5.4°C | 13 mm | 18 cm |
| March | 7°C | −7°C | 0.1°C | 20 mm | 22 cm |
| April | 12°C | −3°C | 4.6°C | 36 mm | 31 cm |
| May | 18°C | 2°C | 9.8°C | 50 mm | 14 cm |
| June | 25°C | 6°C | 15.4°C | 25 mm | 1 cm |
| July | 30°C | 10°C | 19.8°C | 17 mm | 0 cm |
| August | 29°C | 9°C | 18.8°C | 14 mm | 0 cm |
| September | 23°C | 4°C | 13.3°C | 21 mm | 3 cm |
| October | 14°C | −2°C | 6.3°C | 23 mm | 19 cm |
| November | 6°C | −8°C | −1.1°C | 13 mm | 16 cm |
| December | −1°C | −12°C | −6.5°C | 12 mm | 16 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00484925; 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 Jeffrey City?
Normal highs sit between 65°F and 85°F in June, August and September. Of those, August has the fewest days with rain (4).
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 USC00484925.
When is the last frost in Jeffrey City?
In Jeffrey City, the last spring frost (32°F) comes after June 1 in half of years and after June 16 in one year in ten; the first autumn frost comes before September 13 in half of years and before September 1 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 11 year in 10 after June 16; 9 in 10 after May 17
- First autumn frost, half of years before
- September 131 year in 10 before September 1; 9 in 10 before September 28
NOAA puts the median frost-free season at 104 days, and the season without a hard freeze (28°F) at 129 days.
A hard freeze (28°F) comes after May 17 in half of springs and before September 24 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Jeffrey City in zone 4b in ZIP code 82310. By the map's own method, the average of each year's coldest night over 1991-2020, Jeffrey City's NOAA station is in zone 4a: the coldest night of a typical year reaches −26°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 USC00484925; 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 in Jeffrey City?
In a normal year in Jeffrey City, 13 days a year reach 90°F, 207 nights fall to 32°F or colder and 56 days bring measurable precipitation.
- Days at 90°F or more
- 13a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 207a normal year
- Days that stay below freezing
- 59high of 32°F or less
- Days with 0.01 inch of precipitation
- 56a normal year
- Days with 1 inch of snow or more
- 23a normal year
The highest temperature in this station's record (since 1964) is 101°F, on July 16, 2026; the lowest is −49°F, on January 30, 2023.
The wettest calendar year on that record is 2023, with 16.13 in; the snowiest season is 1998–99, with 93.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00484925; records: ACIS (NOAA Regional Climate Centers), station USC00484925. Records use complete months only; a month missing more than three days is left out.
How sunny is Jeffrey City?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Jeffrey City, 4.7 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 2.0 |
| February | 70% | 2.9 |
| March | 72% | 4.2 |
| April | 74% | 5.5 |
| May | 77% | 6.5 |
| June | 85% | 7.6 |
| July | 87% | 7.4 |
| August | 86% | 6.5 |
| September | 86% | 5.2 |
| October | 79% | 3.6 |
| November | 77% | 2.4 |
| December | 67% | 1.7 |
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 Jeffrey City need?
A normal year in Jeffrey City brings 8,486 heating degree days, 58% more than the median U.S. place (5,373), and 230 cooling degree days, 75% 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 1,712 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,395 | 0 |
| February | 1,194 | 0 |
| March | 1,018 | 0 |
| April | 745 | 0 |
| May | 478 | 1 |
| June | 180 | 24 |
| July | 33 | 113 |
| August | 56 | 82 |
| September | 280 | 9 |
| October | 673 | 0 |
| November | 1,047 | 0 |
| December | 1,387 | 0 |
| Year (annual) | 8,486 | 230 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00484925. 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 Jeffrey City been warmer than normal lately?
2025 averaged 46.0°F, 3.7°F above the 1991-2020 normal of 42.3°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 44.2°F | +1.9°F | 9.38 | 47.8 |
| 2022 | 42.7°F | +0.4°F | 14.01 | – |
| 2023 | 41.3°F | −1.0°F | 16.13 | 61.9 |
| 2025 | 46.0°F | +3.7°F | 10.12 | 40.4 |
Over 30 complete years from 1989 to 2025, the station's annual mean temperature rose at a fitted 1.3°F per century (+0.07°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00484925; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Jeffrey City's climate compare?
Jeffrey City is warmer than 21 of the other 70 places with their own NOAA record in Wyoming, and wetter than 19. Across the 7,247 U.S. stations with normals, its annual mean of 42.3°F is warmer than 10%.
In the Köppen classification computed from these normals, Jeffrey City is BSk: cold semi-arid steppe. 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.
Questions about Jeffrey City's climate
What is the coldest month in Jeffrey City?
January, with a normal high of 31°F and a normal low of 9°F. The warmest is July (85°F by day, 50°F at night).
Does it snow in Jeffrey City?
Yes: 60 inches in a normal year, falling on 24 days with 0.1 inch or more, the most in April (12.1 inches).
What is the rainiest month in Jeffrey City?
May, with 1.97 in of precipitation in a normal year; the driest is January with 0.35 in.
What plant hardiness zone is Jeffrey City in?
The USDA's 2023 map puts Jeffrey City in zone 4b in ZIP code 82310. By the same method at Jeffrey City's NOAA station, the coldest night of a typical year reaches −26°F (28 years, 1991-2020): zone 4a.
How late can frost come in Jeffrey City?
In half of years the last 32°F night comes after June 1; in one year in ten it comes after June 16. Waiting until June 16 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Muddy Gap, WY22 miles from this station, 45.4°F a year
- Atlantic City, WY46 miles from this station, 36.5°F a year
- South Pass City, WY50 miles from this station, 35.8°F a year
- Pathfinder Dam, WY50 miles from this station, 46.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made