Illinois · NWS LSX office

Collinsville, IL weather

It is 50°F and clear at St. Louis Downtown Airport as of Oct 28, 12:25 AM CDT. Overnight: Mostly Clear, low near 52°F. Forecast from the National Weather Service, issued Oct 28, 1:26 AM CDT.

Updated Oct 28, 1:30 AM CDT (snapshot)

Current conditions

Temperature

50°F

Clear

Wind

S 3 mph

Humidity 94% · dew point 48°F

Pressure · visibility

30.20 inHg

Visibility 10 mi

Observed at St. Louis Downtown Airport (KCPS), Oct 28, 12:25 AM CDT. Station readings can lag or be missing.

Alerts for this area

No active NWS alerts cover the Collinsville forecast zone right now.

Around the NWS LSX forecast area

No active alerts in zones served by the LSX office near Collinsville.

From the alert snapshot of Oct 28, 2026, 2:15 AM EDT. No alerts are active anywhere in Illinois.

For official warnings, check weather.gov and your local authorities. OpenForecast repeats National Weather Service alerts and may be delayed or incomplete. Follow instructions from emergency officials.

Next 24 hours

Hourly forecast for Collinsville (local time)
TimeTempForecastPrecip. chanceWind
Wed 1 AM56°FMostly Clear2%S 2 mph
Wed 2 AM55°FMostly Clear2%S 2 mph
Wed 3 AM54°FMostly Clear2%S 2 mph
Wed 4 AM54°FMostly Clear2%S 2 mph
Wed 5 AM53°FMostly Clear2%S 2 mph
Wed 6 AM52°FSunny2%S 2 mph
Wed 7 AM52°FSunny2%S 2 mph
Wed 8 AM53°FSunny2%S 3 mph
Wed 9 AM58°FSunny2%S 5 mph
Wed 10 AM65°FSunny2%S 5 mph
Wed 11 AM70°FSunny2%S 6 mph
Wed 12 PM74°FSunny3%S 7 mph
Wed 1 PM77°FSunny2%S 8 mph
Wed 2 PM78°FSunny0%S 9 mph
Wed 3 PM79°FSunny0%S 9 mph
Wed 4 PM80°FSunny2%S 9 mph
Wed 5 PM78°FSunny2%S 8 mph
Wed 6 PM75°FClear0%S 8 mph
Wed 7 PM70°FClear0%S 7 mph
Wed 8 PM65°FClear0%S 7 mph
Wed 9 PM64°FClear0%S 7 mph
Wed 10 PM63°FMostly Clear0%S 7 mph
Wed 11 PM62°FClear0%S 6 mph
Thu 12 AM61°FClear0%S 6 mph

Hourly values come from the NWS gridded forecast for the 2.5 km grid square that covers the city's center point. Conditions elsewhere in Collinsville can differ.

7-day forecast

Overnight

Low 52°F

Mostly clear, with a low around 52. South wind around 2 mph.

Wednesday

High 79°F·Low 56°F

Sunny, with a high near 79. South wind 2 to 9 mph.

Wednesday Night: Clear, with a low around 56. South wind 5 to 8 mph.

Thursday

High 82°F·Low 58°F

Sunny, with a high near 82. Southwest wind around 6 mph.

Thursday Night: Partly cloudy, with a low around 58. North wind around 3 mph.

Friday

High 80°F·Low 59°F

Mostly sunny, with a high near 80.

Friday Night: Mostly cloudy, with a low around 59.

Saturday

High 74°F·Low 57°F

Mostly cloudy, with a high near 74.

Saturday Night: A chance of rain showers after 7pm. Mostly cloudy, with a low around 57. Chance of precipitation is 50%.

Sunday

High 72°F·Low 56°F

A chance of rain showers. Mostly cloudy, with a high near 72. Chance of precipitation is 50%.

Sunday Night: A slight chance of rain showers after midnight. Mostly cloudy, with a low around 56. Chance of precipitation is 20%.

Monday

High 72°F·Low 58°F

A chance of rain showers. Mostly cloudy, with a high near 72. Chance of precipitation is 40%.

Monday Night: A chance of rain showers. Mostly cloudy, with a low around 58. Chance of precipitation is 50%.

Tuesday

High 72°F

Rain showers likely. Mostly cloudy, with a high near 72. Chance of precipitation is 60%.

Nearby cities

Larger cities in the area

Other cities in Madison County

See every city we cover in Illinois, or check all active alerts.

About this forecast

Forecast office
Collinsville is served by the National Weather Service LSX forecast office, forecast zone ILZ100, county zone ILC119.
Location used
The Census Bureau's internal point for Collinsville (38.6757, -90.0058), in Madison County. Population: 23,766 (2024 estimate), number 96 of the 121 Illinois cities on this site.
Radar
Nearest NWS radar: KLSX. View it on radar.weather.gov.

On Amazon

Weather-ready picks

As an Amazon Associate I earn from qualifying purchases.

Home & kitchen LEVOIT Air Purifier An air purifier for smoky or high-pollen days indoors. View on Amazon → Men’s fashion Hanes Fleece Hooded Sweatshirt A warm hoodie for chilly mornings. View on Amazon → Fitness & outdoors Stanley Quencher H2.0 Tumbler A big tumbler for long commutes and outdoor days. View on Amazon → Fitness & outdoors LifeStraw Personal Water Filter A personal water filter worth adding to an emergency kit. View on Amazon →

Sources

  • Forecast, hourly forecast, observations and alerts: National Weather Service API, api.weather.gov/points/38.6757,-90.0058 (forecast issued Oct 28, 1:26 AM CDT).
  • Official forecast page: forecast.weather.gov.
  • City location and population: U.S. Census Bureau, Vintage 2024 population estimates and 2024 Gazetteer files.
  • Snapshot taken Oct 28, 2026. The NWS and Census Bureau do not endorse OpenForecast.

More Illinois cities