San Jose, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for San Jose, a village in Mason County, Illinois.
Today
87°F
Mostly Sunny
Mostly sunny, with a high near 87. South wind around 6 mph.
7-day forecast for San Jose
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Mostly Sunny | 6 mph S | 0% |
| Tonight | 67°F | Partly Cloudy | 5 mph SSE | 6% |
| Wednesday | 85°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 3 to 7 mph S | 29% |
| Wednesday Night | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 mph SSE | 83% |
| Thursday | 81°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph SSW | 81% |
| Thursday Night | 64°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph SSE | 18% |
| Friday | 83°F | Mostly Sunny | 2 mph SSW | 6% |
| Friday Night | 66°F | Slight Chance Showers And Thunderstorms | 2 mph S | 23% |
| Saturday | 86°F | Sunny | 2 to 6 mph SSW | 13% |
| Saturday Night | 71°F | Mostly Clear | 6 mph S | 9% |
| Sunday | 88°F | Sunny | 6 to 10 mph SSW | 6% |
| Sunday Night | 71°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 6 to 9 mph SSW | 15% |
| Monday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 6 to 9 mph SSW | 15% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms | 8 mph SSW | 26% |
Forecast source: National Weather Service (api.weather.gov) for San Jose (40.305, -89.605). Updated through the day.
Growing snapshot for San Jose
Last spring frost
Apr 17
First fall frost
Oct 18
Growing season
182 days
Hardiness zone
6a
More local growing data for San Jose: nearby ZIP 62682 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mason City 4Se, Il (9.4 mi from San Jose). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.