Current Conditions

Alton, Illinois

83°F29°C

Hot

Wind

SSW 8 mph14 km/h

Humidity

61%

Cloud Cover

As of Wednesday, September 2, 2026 at 1:23 AM CDT

Today's Outlook

Day

Mostly clear and hot, with a high of 101°F38°C and morning low of 78°F26°C. Breezy from the SW at 7 mph11 km/h. Heat risk in the afternoon.

Night

Mostly clear, with a low around 81°F27°C. Breezy from the S at 7 to 8 mph11 to 14 km/h.

7-Day Forecast

Condition	High (°F)	Low (°F)	Precip (mm)	Cloud Cover (%)	Wind (mph)
Hot	High 101°F38°C	Low 78°F26°C	Precip 0 in0 mm—	Cloud 14%	Wind SSW 7 mph11 km/h	Wednesday: Mostly clear and hot, with a high of 101°F38°C and morning low of 78°F26°C. Breezy from the SW at 7 mph11 km/h. Heat risk in the afternoon. Wednesday Night: Mostly clear, with a low around 81°F27°C. Breezy from the S at 7 to 8 mph11 to 14 km/h.
Hot	High 100°F38°C	Low 77°F25°C	Precip 0 in0 mm—	Cloud 8%	Wind SSW 6 mph10 km/h	Thursday: Mostly clear and hot, with a high of 100°F38°C and morning low of 77°F25°C. Light wind from the SW around 6 mph10 km/h. Heat risk in the afternoon. Thursday Night: Mostly clear, with a low around 80°F27°C. Breezy from the S at 6 to 8 mph10 to 13 km/h.
Hot	High 101°F38°C	Low 78°F25°C	Precip 0 in0 mm—	Cloud 12%	Wind SSW 4 mph7 km/h	Friday: Mostly clear and hot, with a high of 101°F38°C and morning low of 78°F25°C. Light wind from the SW around 4 mph6 km/h. Heat risk in the afternoon. Friday Night: Mostly clear, with a low around 80°F27°C. Breezy from the S at 5 to 7 mph8 to 11 km/h.
Drizzle	High 100°F38°C	Low 78°F26°C	Precip 0.02 in0.6 mm23%	Cloud 41%	Wind ESE 4 mph6 km/h	Saturday: Partly cloudy and hot, with a high of 100°F38°C and morning low of 78°F26°C. Light wind from the NNW around 3 mph5 km/h. 23% chance of drizzle in the afternoon. Heat risk in the afternoon. Saturday Night: Partly cloudy, with a low around 81°F27°C. Light wind from the SE around 4 mph7 km/h. 22% chance of drizzle in the evening.
Drizzle	High 93°F34°CFeels 98°F37°C	Low 76°F25°C	Precip 0.03 in0.7 mm16%	Cloud 48%	Wind ENE 5 mph8 km/h	Sunday: Mostly cloudy and hot, with a high of 93°F34°C and morning low of 76°F25°C. Light wind from the ENE around 5 mph8 km/h. 16% chance of drizzle in the afternoon. Heat risk in the afternoon. Sunday Night: Partly cloudy, with a low around 79°F26°C. Light wind from the E around 5 mph9 km/h. 12% chance of drizzle before dawn.
Partly Cloudy	High 93°F34°C	Low 73°F23°C	Precip 0.02 in0.5 mm4%	Cloud 44%	Wind ESE 6 mph9 km/h	Monday: Partly cloudy and hot, with a high of 93°F34°C and morning low of 73°F23°C. Light wind from the ESE around 5 mph8 km/h. Humid. Monday Night: Partly cloudy, with a low around 76°F24°C. Breezy from the E at 6 to 7 mph10 to 12 km/h.
Hot	High 97°F36°C	Low 73°F23°C	Precip 0 in0.1 mm3%	Cloud 43%	Wind SSE 7 mph11 km/h	Tuesday: Partly cloudy and hot, with a high of 97°F36°C and morning low of 73°F23°C. Breezy from the S at 6 to 7 mph10 to 11 km/h. Heat risk in the afternoon. Tuesday Night: Partly cloudy, with a low around 75°F24°C. Breezy from the SSE at 7 to 9 mph11 to 14 km/h.

15-Day Forecast

	Day	High	Low	Precip	Cloud Cover	Condition	Wind
	WednesdaySep 2	101°F38°C	78°F26°C	0 in0 mm· —	14%	Hot	SSW 7 mph11 km/h
DayMostly clear and hot, with a high of 101°F38°C and morning low of 78°F26°C. Breezy from the SW at 7 mph11 km/h. Heat risk in the afternoon. NightMostly clear, with a low around 81°F27°C. Breezy from the S at 7 to 8 mph11 to 14 km/h.
	ThursdaySep 3	100°F38°C	77°F25°C	0 in0 mm· —	8%	Hot	SSW 6 mph10 km/h
DayMostly clear and hot, with a high of 100°F38°C and morning low of 77°F25°C. Light wind from the SW around 6 mph10 km/h. Heat risk in the afternoon. NightMostly clear, with a low around 80°F27°C. Breezy from the S at 6 to 8 mph10 to 13 km/h.
	FridaySep 4	101°F38°C	78°F25°C	0 in0 mm· —	12%	Hot	SSW 4 mph7 km/h
DayMostly clear and hot, with a high of 101°F38°C and morning low of 78°F25°C. Light wind from the SW around 4 mph6 km/h. Heat risk in the afternoon. NightMostly clear, with a low around 80°F27°C. Breezy from the S at 5 to 7 mph8 to 11 km/h.
	SaturdaySep 5	100°F38°C	78°F26°C	0.02 in0.6 mm· 23%	41%	Drizzle	ESE 4 mph6 km/h
DayPartly cloudy and hot, with a high of 100°F38°C and morning low of 78°F26°C. Light wind from the NNW around 3 mph5 km/h. 23% chance of drizzle in the afternoon. Heat risk in the afternoon. NightPartly cloudy, with a low around 81°F27°C. Light wind from the SE around 4 mph7 km/h. 22% chance of drizzle in the evening.
	SundaySep 6	93°F34°C Feels 98°F37°C	76°F25°C	0.03 in0.7 mm· 16%	48%	Drizzle	ENE 5 mph8 km/h
DayMostly cloudy and hot, with a high of 93°F34°C and morning low of 76°F25°C. Light wind from the ENE around 5 mph8 km/h. 16% chance of drizzle in the afternoon. Heat risk in the afternoon. NightPartly cloudy, with a low around 79°F26°C. Light wind from the E around 5 mph9 km/h. 12% chance of drizzle before dawn.
	MondaySep 7	93°F34°C	73°F23°C	0.02 in0.5 mm· 4%	44%	Partly Cloudy	ESE 6 mph9 km/h
DayPartly cloudy and hot, with a high of 93°F34°C and morning low of 73°F23°C. Light wind from the ESE around 5 mph8 km/h. Humid. NightPartly cloudy, with a low around 76°F24°C. Breezy from the E at 6 to 7 mph10 to 12 km/h.
	TuesdaySep 8	97°F36°C	73°F23°C	0 in0.1 mm· 3%	43%	Hot	SSE 7 mph11 km/h
DayPartly cloudy and hot, with a high of 97°F36°C and morning low of 73°F23°C. Breezy from the S at 6 to 7 mph10 to 11 km/h. Heat risk in the afternoon. NightPartly cloudy, with a low around 75°F24°C. Breezy from the SSE at 7 to 9 mph11 to 14 km/h.
	WednesdaySep 9	98°F36°C Feels 102°F39°C	78°F26°C	0.01 in0.2 mm· 8%	26%	Hot	SSW 8 mph13 km/h
DayPartly cloudy and hot, with a high of 98°F36°C and morning low of 78°F26°C. Breezy from the SSW at 8 mph13 km/h. Heat risk in the afternoon. NightPartly cloudy, with a low around 80°F27°C. Breezy from the S at 8 to 9 mph13 to 14 km/h.
	ThursdaySep 10	95°F35°C Feels 99°F37°C	78°F26°C	0.06 in1.6 mm· 15%	37%	Drizzle	SW 8 mph12 km/h
DayPartly cloudy and hot, with a high of 95°F35°C and morning low of 78°F26°C. Breezy from the SW at 7 to 8 mph12 to 12 km/h. 10% chance of drizzle throughout the day. Heat risk in the afternoon. NightPartly cloudy, with a low around 80°F27°C. Breezy from the SSW at 8 to 9 mph12 to 14 km/h. 15% chance of drizzle throughout the night.
	FridaySep 11	90°F32°C	75°F24°C	0.14 in3.5 mm· 22%	48%	Showers	SSW 7 mph11 km/h
DayMostly cloudy and hot, with a high of 90°F32°C and morning low of 75°F24°C. Breezy from the SW at 7 to 8 mph11 to 12 km/h. 21% chance of showers throughout the day. Humid. NightPartly cloudy, with a low around 77°F25°C. Breezy from the S at 7 to 8 mph11 to 12 km/h. 22% chance of showers throughout the night.
	SaturdaySep 12	89°F32°C	72°F22°C	0.13 in3.4 mm· 18%	51%	Showers	S 7 mph12 km/h
DayMostly cloudy and hot, with a high of 89°F32°C and morning low of 72°F22°C. Breezy from the SSW at 7 to 8 mph12 to 13 km/h. 18% chance of showers throughout the day. Humid. NightMostly cloudy, with a low around 74°F24°C. Breezy from the S at 7 mph11 km/h. 17% chance of showers throughout the night.
	SundaySep 13	88°F31°C	72°F22°C	0.15 in3.9 mm· 19%	54%	Showers	SSW 8 mph12 km/h
DayMostly cloudy and hot, with a high of 88°F31°C and morning low of 72°F22°C. Breezy from the SSW at 8 mph13 km/h. 19% chance of showers throughout the day. Humid. NightMostly cloudy, with a low around 74°F23°C. Breezy from the S at 7 to 8 mph12 to 12 km/h. 19% chance of showers throughout the night.
	MondaySep 14	85°F30°C	71°F22°C	0.19 in4.9 mm· 26%	56%	Showers	SSW 7 mph11 km/h
DayMostly cloudy and warm, with a high of 85°F30°C and morning low of 71°F22°C. Breezy from the SSW at 7 to 8 mph12 to 13 km/h. 26% chance of showers throughout the day. Humid. NightMostly cloudy, with a low around 73°F23°C. Breezy from the S at 7 mph11 km/h. 19% chance of showers throughout the night.
	TuesdaySep 15	85°F29°C	69°F20°C	0.17 in4.3 mm· 22%	54%	Showers	S 7 mph11 km/h
DayMostly cloudy and warm, with a high of 85°F29°C and morning low of 69°F20°C. Breezy from the SSW at 7 mph11 km/h. 22% chance of showers throughout the day. NightMostly cloudy, with a low around 70°F21°C. Breezy from the SSE at 6 to 7 mph10 to 11 km/h. 19% chance of showers throughout the night.
	WednesdaySep 16	84°F29°C	67°F19°C	0.08 in2 mm· 14%	49%	Showers	SSE 6 mph10 km/h
DayMostly cloudy and warm, with a high of 84°F29°C and morning low of 67°F19°C. Breezy from the SW at 6 to 7 mph10 to 11 km/h. 14% chance of drizzle throughout the day. NightPartly cloudy, with a low around 69°F20°C. Light wind from the ESE around 6 mph10 km/h. 12% chance of showers throughout the night.

Nearby Cities

Upper Alton2 mi4 km Godfrey4 mi7 km Old Jamestown7 mi11 km Spanish Lake7 mi12 km Florissant10 mi16 km Ferguson12 mi19 km

About This Forecast

This forecast is powered by WeatherMesh, the world's most advanced and accurate weather model powered by AI. WeatherMesh is built on proprietary data from WindBorne's Global Sounding Balloon constellation — the world's largest fleet of autonomous, long-duration weather balloons — collecting observations across 100% of Earth, including over oceans and remote regions where no other data exists.

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Coordinates: 38.8906°N, 90.1843°W·Elevation: 150m·Timezone: America/Chicago·Population: 27,003