Johnstown, WY Weather & Growing Conditions
Today
80°F
Areas Of Smoke
Areas of smoke. Sunny, with a high near 80. East wind 3 to 12 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 80°F | Areas Of Smoke | 3 to 12 mph E | 0% |
| Tonight | 50°F | Areas Of Smoke | 3 to 12 mph NW | 2% |
| Wednesday | 87°F | Sunny | 3 to 10 mph SW | 0% |
| Wednesday Night | 53°F | Mostly Clear | 12 mph WNW | 0% |
| Thursday | 93°F | Sunny | 6 to 13 mph NW | 0% |
| Thursday Night | 59°F | Mostly Clear | 10 to 16 mph WNW | 0% |
| Friday | 96°F | Sunny | 6 to 15 mph WNW | 1% |
| Friday Night | 61°F | Mostly Clear | 16 to 21 mph WNW | 0% |
| Saturday | 96°F | Sunny | 15 mph NW | 1% |
| Saturday Night | 60°F | Mostly Clear | 12 to 17 mph WNW | 0% |
| Sunday | 95°F | Sunny | 10 mph NNW | 4% |
| Sunday Night | 60°F | Partly Cloudy | 10 to 16 mph WNW | 1% |
| Monday | 93°F | Sunny | 9 mph N | 5% |
| Monday Night | 59°F | Partly Cloudy | 10 to 14 mph NW | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Johnstown, WY
Last spring frost
May 21
First fall frost
Sep 20
Growing season
119 days
Hardiness zone
5a
Explore more for Johnstown, WY: full frost dates · planting calendar · Wyoming frost dates
Climate data from the nearest NOAA station, Diversion Dam, Wy (4.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.