Alto Pass, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Alto Pass, a village in Union County, Illinois.
This Afternoon
99°F
Slight Chance Showers And Thunderstorms
A slight chance of rain showers before 4pm, then a slight chance of showers and thunderstorms. Mostly sunny. High near 99, with temperatures falling to around 96 in the afternoon. Heat index values as high as 106. South wind around 6 mph. Chance of precipitation is 20%.
7-day forecast for Alto Pass
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 99°F | Slight Chance Showers And Thunderstorms | 6 mph S | 22% |
| Tonight | 72°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 2 mph SSE | 19% |
| Saturday | 97°F | Sunny | 2 to 7 mph SW | 3% |
| Saturday Night | 72°F | Partly Cloudy | 5 mph SSW | 0% |
| Sunday | 96°F | Sunny | 3 to 7 mph WSW | 4% |
| Sunday Night | 70°F | Partly Cloudy | 5 mph N | 10% |
| Monday | 87°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 7 mph N | 47% |
| Monday Night | 64°F | Chance Showers And Thunderstorms | 5 to 8 mph N | 47% |
| Tuesday | 76°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 7 to 12 mph N | 15% |
| Tuesday Night | 58°F | Partly Cloudy | 5 to 12 mph N | 8% |
| Wednesday | 76°F | Mostly Sunny | 8 mph N | 3% |
| Wednesday Night | 57°F | Partly Cloudy | 3 to 7 mph NNE | 2% |
| Thursday | 76°F | Mostly Sunny | 3 to 8 mph N | 3% |
| Thursday Night | 59°F | Partly Cloudy | 3 to 7 mph NNE | 3% |
Forecast source: National Weather Service (api.weather.gov) for Alto Pass (37.574, -89.320). Updated through the day.
Growing snapshot for Alto Pass
Last spring frost
Apr 8
First fall frost
Oct 29
Growing season
203 days
Hardiness zone
7a
More local growing data for Alto Pass: nearby ZIP 62905 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Anna 2 Nne, Il (9 mi from Alto Pass). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.