Weather in Mount Vernon, Illinois
Live weather conditions. Source: Open-Meteo
Updated May 30, 2026 · 03:27 AMET · Refreshes every hour
69°F
Partly cloudy
Feels like 72°F
85%
Humidity
3 mph
Wind Speed
7-Day Forecast
Sat
May 30
☁️
Cloudy
86°
66°
Sun
May 31
☁️
Cloudy
86°
64°
Mon
Jun 1
🌧️
Rain
81°
62°
Tue
Jun 2
⛅
Partly Cloudy
76°
58°
Wed
Jun 3
☁️
Cloudy
76°
54°
Thu
Jun 4
☁️
Cloudy
79°
57°
Fri
Jun 5
☁️
Cloudy
82°
60°
About Weather in Mount Vernon
Mount Vernon is located in Illinois at coordinates 38.314205°N, 88.91747°W. Weather data is sourced from Open-Meteo, a free and open meteorological API that combines data from national weather services including NOAA, the European Centre for Medium-Range Weather Forecasts (ECMWF), and others.
All temperatures are displayed in Fahrenheit. Wind speed is in miles per hour. The 7-day forecast uses the best available global forecast model for Mount Vernon's location. Data is refreshed every hour.
Other Cities in Illinois
Frequently Asked Questions
How accurate is this weather data?▾
Weather data from Open-Meteo achieves approximately ±2°F accuracy for temperature within the first 24 hours. Accuracy decreases with forecast range — 1-3 day forecasts are quite reliable, while 5-7 day forecasts are directionally accurate but less precise. Open-Meteo uses multiple global weather models and selects the best one for each location.
Why are temperatures shown in Fahrenheit?▾
This site is designed primarily for a US audience, so temperatures are shown in Fahrenheit (°F), the standard unit used in the United States. To convert: °C = (°F - 32) × 5/9. For example, 77°F = 25°C, 32°F = 0°C (freezing), 98.6°F = 37°C (body temperature).
What is the climate like in Mount Vernon?▾
Mount Vernon is located in Illinois in the central United States. The current conditions shown reflect real-time weather. For historical climate normals (average temperatures by month), the NOAA Climate Data Online tool provides 30-year climate averages for most US cities.
How often is weather data updated?▾
Current conditions are refreshed every hour. The 7-day forecast uses Open-Meteo's latest model run, which is updated every 6 hours with new data from global weather observations including weather balloons, satellites, and ground stations.