Potosi, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Potosi, a city in Washington County, Missouri.
Overnight
61°F
Clear
Clear, with a low around 61. South wind around 2 mph.
7-day forecast for Potosi
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Clear | 2 mph S | 0% |
| Tuesday | 89°F | Sunny | 2 mph S | 0% |
| Tuesday Night | 67°F | Mostly Clear | 3 mph S | 0% |
| Wednesday | 91°F | Sunny | 5 mph S | 5% |
| Wednesday Night | 70°F | Partly Cloudy then Chance Showers And Thunderstorms | 5 mph S | 50% |
| Thursday | 88°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 3 mph S | 67% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms | 2 mph S | 47% |
| Friday | 88°F | Chance Showers And Thunderstorms | 3 mph SW | 47% |
| Friday Night | 69°F | Chance Showers And Thunderstorms | 2 mph SW | 45% |
| Saturday | 89°F | Chance Showers And Thunderstorms | 3 mph SW | 30% |
| Saturday Night | 70°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 5 mph S | 16% |
| Sunday | 91°F | Sunny | 6 mph SW | 3% |
| Sunday Night | 72°F | Mostly Clear | 5 mph S | 3% |
| Monday | 93°F | Sunny | 6 mph SW | 3% |
Forecast source: National Weather Service (api.weather.gov) for Potosi (37.934, -90.775). Updated through the day.
Growing snapshot for Potosi
Last spring frost
Apr 11
First fall frost
Oct 28
Growing season
198 days
Hardiness zone
6b
More local growing data for Potosi: nearby ZIP 63660 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Potosi 4 Sw, Mo (7.5 mi from Potosi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.