San Jose, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for San Jose, a village in Mason County, Illinois.
This Afternoon
71°F
Light Rain
Rain and a slight chance of thunderstorms. Mostly cloudy, with a high near 71. South wind around 18 mph, with gusts as high as 35 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for San Jose
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 71°F | Light Rain | 18 mph S | 87% |
| Tonight | 53°F | Rain | 13 to 17 mph S | 80% |
| Wednesday | 60°F | Chance Rain Showers then Mostly Cloudy | 12 to 15 mph SW | 13% |
| Wednesday Night | 44°F | Mostly Cloudy | 10 mph SW | 1% |
| Thursday | 60°F | Mostly Sunny | 8 to 13 mph WSW | 7% |
| Thursday Night | 42°F | Mostly Cloudy then Slight Chance Light Rain | 7 mph NW | 24% |
| Friday | 55°F | Partly Sunny then Slight Chance Light Rain | 7 to 10 mph NNW | 15% |
| Friday Night | 35°F | Partly Cloudy | 2 to 8 mph NNW | 3% |
| Saturday | 54°F | Mostly Sunny | 5 mph NW | 2% |
| Saturday Night | 34°F | Partly Cloudy | 2 mph W | 2% |
| Sunday | 61°F | Sunny | 2 to 8 mph WNW | 11% |
| Sunday Night | 34°F | Mostly Clear | 6 mph W | 5% |
| Monday | 64°F | Sunny | 3 to 10 mph SW | 2% |
| Monday Night | 39°F | Mostly Clear | 3 to 7 mph WSW | 1% |
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 Nov 4, 2026.