Johnstown, WY Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Johnstown, a community in Fremont County, Wyoming.
Today
82°F
Areas Of Smoke
Areas of smoke. Sunny, with a high near 82. East wind 6 to 9 mph.
7-day forecast for Johnstown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 82°F | Areas Of Smoke | 6 to 9 mph E | 1% |
| Tonight | 52°F | Areas Of Smoke | 2 to 10 mph N | 1% |
| Wednesday | 88°F | Areas Of Smoke | 2 to 7 mph NE | 0% |
| Wednesday Night | 53°F | Areas Of Smoke | 7 to 12 mph WNW | 0% |
| Thursday | 96°F | Areas Of Smoke then Sunny | 5 to 15 mph NW | 0% |
| Thursday Night | 57°F | Mostly Clear | 6 to 17 mph NW | 0% |
| Friday | 97°F | Sunny | 5 to 12 mph NW | 0% |
| Friday Night | 59°F | Mostly Clear | 10 to 16 mph WNW | 0% |
| Saturday | 98°F | Sunny | 7 mph NNW | 1% |
| Saturday Night | 60°F | Mostly Clear | 10 to 16 mph WNW | 0% |
| Sunday | 97°F | Sunny | 6 to 12 mph WNW | 4% |
| Sunday Night | 62°F | Mostly Clear | 8 to 14 mph WNW | 2% |
| Monday | 96°F | Sunny | 9 mph N | 6% |
| Monday Night | 61°F | Partly Cloudy | 8 to 13 mph NW | 4% |
Forecast source: National Weather Service (api.weather.gov) for Johnstown (43.114, -108.690). Updated through the day.
Growing snapshot for Johnstown
Last spring frost
May 16
First fall frost
Sep 28
Growing season
133 days
Hardiness zone
5a
More local growing data for Johnstown: nearby ZIP 82510 weather · frost dates · planting calendar · Wyoming frost dates
Nearby towns & communities
Arapahoe
Atlantic City
Boulder Flats
Crowheart
Dubois
Ethete
Fort Washakie
Hudson
Jeffrey City
Lander
Pavillion
Riverton
Shoshoni
Climate data from the nearest NOAA station, Riverton, Wy (8.1 mi from Johnstown). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.