Local weather forecast

Weather in Alton, IL

Updated 2026-08-11 12:30 local time · ZIP codes 62002

Sunny
Now91°F

Sunny

High / Low102° / 77°
Rain chance3%
Wind14 mph
Weather alerts

Active alerts

1
Heat Advisory issued August 11 at 2:17AM CDT until August 12 at 8:00PM CDT by NWS St Louis MO

* WHAT...Heat index values up to 106. * WHERE...Portions of south central, southwest, and west central Illinois and central, east central, northeast, and southeast Missouri. * WHEN...Until 8 PM CDT Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.

Safety instructions

Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1.

Hourly

Next hours

NowSunny91°1% rain
2 PMSunny102°1% rain
3 PMSunny101°1% rain
4 PMSunny101°1% rain
5 PMSunny100°1% rain
6 PMSunny99°1% rain
7 PMSunny96°1% rain
8 PMSunny91°1% rain
9 PMClear88°2% rain
10 PMClear85°3% rain
11 PMClear84°3% rain
12 AMClear80°4% rain
Forecast

3-day weather forecast

Today2026-08-11
Sunny
102° 77°Sunny
Rain 3%Gust 14 mph
Tomorrow2026-08-12
Sunny
93° 78°Sunny
Rain 36%Gust 10 mph
Thursday2026-08-13
Sunny
96° 72°Sunny
Rain 21%Gust 15 mph
Conditions

Weather details

Feels like97°F
Humidity59%
Pressure29.98 inHg
Visibility10 mi
Wind14 mph WSW
Wind gusts17 mph
Precipitation0.00 in
UV index8
Daylight

Sunrise, sunset and moon

Sunrise06:10 AM
Sunset08:00 PM
Moonrise04:13 AM
Moon phaseNew Moon
Practical guide

Weather insights for today

Umbrella not essential

Rain chance stays relatively low over the next 12 hours (up to 4%).

Choose light, breathable clothing

It feels like 97°F with winds near 14 mph.

Best window: 8 PM

91°F, 1% rain chance and 8 mph wind.

Driving conditions look generally normal

Visibility is around 10 mi; gusts may reach 17 mph.

Running conditions are less comfortable

Current temperature is 91°F, wind 14 mph, rain chance up to 4%.

High UV protection needed

UV index is 8. Sunscreen, shade and protective clothing are recommended.

Alton weather today

Sunny and 91°F in Alton, IL. Today's high is 102°F with a 3% rain chance. Winds are around 14 mph with gusts near 17 mph. Relative humidity is 59%, pressure is 29.98 inHg, and visibility is about 10 miles.

Tonight and tomorrow in Alton

Sunrise is at 06:10 AM and sunset is at 08:00 PM. Tomorrow's forecast calls for Sunny with a high near 93°F and a low near 78°F. The maximum rain chance is 36%.

Nearby

Weather near Alton

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