Alton, Illinois Weather Conditions

Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Current Conditions

  • 84°
  • Mostly Cloudy
  • Wind: SE 7 mph
  • Humidity: 79%
  • Visibility: 10.0 miles
  • Dew Point: 77°
  • Pressure: 30.01 in. 0
  • Heat Index: 94

Select a Section

Click a section below for more information.

Next 12 Hours

10  pm
1  am
4  am
7  am
10  am
Chance of a Thunderstorm
Chance of T-storms
Chance of a Thunderstorm
Chance of T-storms
Thunderstorm
T-storms
Chance of a Thunderstorm
Chance of T-storms
Chance of a Thunderstorm
Chance of T-storms
79°
79°
77°
75°
75°
Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Wednesday
  • Chance of a Thunderstorm
  • High: 81 °
  • Low: 59 °
  • Chance of T-Storms
  • Thursday
  • Clear
  • High: 77 °
  • Low: 57 °
  • Clear
  • Friday
  • Chance of a Thunderstorm
  • High: 81 °
  • Low: 70 °
  • Chance of a Thunderstorm
  • Saturday
  • Chance of a Thunderstorm
  • High: 88 °
  • Low: 68 °
  • Chance of T-Storms
  • Sunday
  • Chance of a Thunderstorm
  • High: 84 °
  • Low: 54 °
  • Chance of a Thunderstorm

Forecast for Alton, Illinois

Updated: 10:00 PM CDT on July 22, 2014

  • Tuesday

    Clear in the morning, then partly cloudy. High of 93F. Winds from the South at 5 to 15 mph.

  • Tuesday Night

    Partly cloudy with a chance of a thunderstorm and a chance of rain, then thunderstorms after midnight. Low of 75F. Winds from the South at 5 to 10 mph. Chance of rain 60% with rainfall amounts near 0.3 in. possible.

  • Wednesday

    Partly cloudy with a chance of a thunderstorm and a chance of rain. High of 81F. Winds from the NNW at 5 to 15 mph. Chance of rain 30%.

  • Wednesday Night

    Partly cloudy in the evening, then clear. Low of 59F. Winds from the NNE at 5 to 15 mph.

  • Thursday

    Clear. High of 77F. Winds from the NNE at 5 to 10 mph.

  • Thursday Night

    Partly cloudy. Low of 57F. Winds from the East at 5 to 10 mph.

  • Friday

    Clear in the morning, then partly cloudy. High of 81F. Winds from the SSE at 5 to 10 mph. Chance of rain 20%.

  • Friday Night

    Partly cloudy with a chance of a thunderstorm and a chance of rain. Low of 70F. Winds from the South at 10 to 15 mph.

  • Saturday

    Partly cloudy with a chance of a thunderstorm and rain, then a chance of rain in the afternoon. High of 88F with a heat index of 95F. Winds from the SSW at 10 to 15 mph. Chance of rain 70% with rainfall amounts near 0.3 in. possible.

  • Saturday Night

    Partly cloudy with a chance of a thunderstorm and rain. Fog overnight. Low of 68F. Winds from the SW at 5 to 10 mph. Chance of rain 70% with rainfall amounts near 0.7 in. possible.

  • Sunday

    Partly cloudy with a chance of a thunderstorm and rain. High of 84F. Winds from the NW at 10 to 15 mph. Chance of rain 20%.

  • Sunday Night

    Clear. Fog overnight. Low of 54F. Winds from the NNW at 5 to 15 mph.

  • Monday

    Partly cloudy. High of 77F. Winds from the NNW at 5 to 10 mph.

  • Monday Night

    Clear. Low of 55F. Winds less than 5 mph.

  • Tuesday

    Partly cloudy. High of 79F. Winds less than 5 mph.

  • Tuesday Night

    Clear. Low of 52F. Winds less than 5 mph.

  • Wednesday

    Clear with a chance of a thunderstorm. High of 79F. Winds less than 5 mph. Chance of rain 20%.

  • Wednesday Night

    Partly cloudy with a chance of a thunderstorm. Fog overnight. Low of 55F. Winds less than 5 mph. Chance of rain 50% with rainfall amounts near 0.3 in. possible.

  • Thursday

    Clear with a chance of a thunderstorm. High of 79F. Winds less than 5 mph. Chance of rain 50%.

  • Thursday Night

    Clear. Fog overnight. Low of 52F. Winds less than 5 mph.

  • Friday

    Clear with a chance of a thunderstorm. High of 81F. Winds less than 5 mph. Chance of rain 40%.

  • Friday Night

    Clear. Fog overnight. Low of 54F. Winds less than 5 mph.

  • Saturday

    Clear. High of 81F. Winds less than 5 mph.

  • Saturday Night

    Clear. Fog overnight. Low of 54F. Winds less than 5 mph.

Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: MesoWest ALTON IL US UPR, Alton, IL

Updated: 6:15 PM CDT

Temperature: 97 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 92 °F Graphs

Location: Alton - Beacon, Alton, IL

Updated: 8:38 PM CDT

Temperature: 85.0 °F Dew Point: 75 °F Humidity: 72% Wind: ENE at 2.0 mph Pressure: 29.97 in Hourly Precipitation: 0.00 in Heat Index: 93 °F Graphs

Location: Alton - Christian Hill Area, Alton, IL

Updated: 8:35 PM CDT

Temperature: 84.3 °F Dew Point: 72 °F Humidity: 67% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Heat Index: 90 °F Graphs

Location: Alton - Rock Gate Estates, Alton, IL

Updated: 8:38 PM CDT

Temperature: 84.5 °F Dew Point: 73 °F Humidity: 69% Wind: Calm Pressure: 30.02 in Hourly Precipitation: 0.00 in Heat Index: 91 °F Graphs

Location: Milton Area - Oscar, Alton, IL

Updated: 8:35 PM CDT

Temperature: 85.0 °F Dew Point: 72 °F Humidity: 66% Wind: Calm Pressure: 29.94 in Hourly Precipitation: 0.00 in Heat Index: 91 °F Graphs

Location: Brecht Ln, Godfrey, IL

Updated: 8:24 PM CDT

Temperature: 83.3 °F Dew Point: 73 °F Humidity: 71% Wind: SE at 2.7 mph Pressure: 29.85 in Hourly Precipitation: - Heat Index: 89 °F Graphs

Location: Godfrey River Aire Subdivision, Godfrey, IL

Updated: 8:38 PM CDT

Temperature: 83.1 °F Dew Point: 75 °F Humidity: 76% Wind: SSE at 1.0 mph Pressure: 29.94 in Hourly Precipitation: 0.00 in Heat Index: 90 °F Graphs

Location: Rosewood Heights, East Alton, IL

Updated: 8:38 PM CDT

Temperature: 83.8 °F Dew Point: 70 °F Humidity: 63% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Heat Index: 88 °F Graphs

Location: Foster Township, Alton, IL

Updated: 8:37 PM CDT

Temperature: 82.0 °F Dew Point: 75 °F Humidity: 79% Wind: Calm Pressure: 29.96 in Hourly Precipitation: - Heat Index: 89 °F Graphs

Location: Jersey County along IL 111, Brighton, IL

Updated: 8:38 PM CDT

Temperature: 83.1 °F Dew Point: 72 °F Humidity: 68% Wind: Calm Pressure: 29.68 in Hourly Precipitation: 0.00 in Heat Index: 88 °F Graphs

Location: Timber Ridge, Godfrey, IL

Updated: 8:35 PM CDT

Temperature: 81.7 °F Dew Point: 77 °F Humidity: 86% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Heat Index: 90 °F Graphs

Location: Jost Farm, Florissant, MO

Updated: 8:35 PM CDT

Temperature: 85.5 °F Dew Point: 67 °F Humidity: 54% Wind: SW at 2.2 mph Pressure: 29.78 in Hourly Precipitation: 0.00 in Heat Index: 88 °F Graphs

Location: MesoWest NAMOK2 IL US UPR, Granite City, IL

Updated: 7:30 PM CDT

Temperature: 90 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 87 °F Graphs

Location: MesoWest NAMOK1 IL US UPR, Granite City, IL

Updated: 6:55 PM CDT

Temperature: 92 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 88 °F Graphs

Location: Grand Ave, Edwardsville, IL

Updated: 8:38 PM CDT

Temperature: 83.3 °F Dew Point: 73 °F Humidity: 72% Wind: Calm Pressure: 29.84 in Hourly Precipitation: 0.00 in Heat Index: 90 °F Graphs

Location: Knight Compound, Dorsey, IL

Updated: 8:38 PM CDT

Temperature: 78.0 °F Dew Point: 74 °F Humidity: 87% Wind: Calm Pressure: 29.81 in Hourly Precipitation: 0.00 in Heat Index: 80 °F Graphs

Location: Riverwood Place, Florissant, MO

Updated: 8:38 PM CDT

Temperature: 86.1 °F Dew Point: 74 °F Humidity: 67% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Heat Index: 94 °F Graphs

Location: Nickel Plate Trail, Edwardsville, IL

Updated: 8:35 PM CDT

Temperature: 80.6 °F Dew Point: 74 °F Humidity: 81% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Heat Index: 86 °F Graphs

Location: Dunlap Lake, Edwardsville, IL

Updated: 8:31 PM CDT

Temperature: 82.9 °F Dew Point: 73 °F Humidity: 72% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Heat Index: 89 °F Graphs

Location: MesoWest SHPMAN IL US UPR, Shipman, IL

Updated: 7:35 PM CDT

Temperature: 81 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 79 °F Graphs

Location: Piasa, Piasa, IL

Updated: 8:35 PM CDT

Temperature: 82.0 °F Dew Point: 75 °F Humidity: 78% Wind: SE at 4.0 mph Pressure: 29.92 in Hourly Precipitation: 0.00 in Heat Index: 88 °F Graphs

Location: Kelly Greens Weather Station, Edwardsville, IL

Updated: 8:38 PM CDT

Temperature: 80.8 °F Dew Point: 73 °F Humidity: 77% Wind: Calm Pressure: 29.99 in Hourly Precipitation: 0.00 in Heat Index: 85 °F Graphs

Location: MesoWest GARD IL US UPR, Hamel, IL

Updated: 5:55 PM CDT

Temperature: 86 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Heat Index: 83 °F Graphs

Location: APRSWXNET Berkeley MO US, Woodson Terrace, MO

Updated: 4:46 PM CDT

Temperature: 91 °F Dew Point: 71 °F Humidity: 52% Wind: ESE at 3 mph Pressure: 30.03 in Hourly Precipitation: 0.00 in Heat Index: 98 °F Graphs

Location: Barbarotto Compound, Maryville, IL

Updated: 8:38 PM CDT

Temperature: 81.4 °F Dew Point: 72 °F Humidity: 72% Wind: Calm Pressure: 29.92 in Hourly Precipitation: 0.00 in Heat Index: 86 °F Graphs

Location: 1 Mile South of St. Louis Lambert Airport, Woodson Terrace, MO

Updated: 8:38 PM CDT

Temperature: 86.1 °F Dew Point: 75 °F Humidity: 69% Wind: Calm Pressure: 30.00 in Hourly Precipitation: 0.00 in Heat Index: 95 °F Graphs

Location: Rolling Meadows Dr, Maryville, IL

Updated: 8:38 PM CDT

Temperature: 81.9 °F Dew Point: 68 °F Humidity: 64% Wind: Calm Pressure: 29.38 in Hourly Precipitation: 0.00 in Heat Index: 85 °F Graphs

Location: Polestar Boating Center, St. Charles, MO

Updated: 8:38 PM CDT

Temperature: 83.4 °F Dew Point: 77 °F Humidity: 82% Wind: Calm Pressure: 30.03 in Hourly Precipitation: 0.00 in Heat Index: 93 °F Graphs

Location: St. Ann, MO, St. Ann, MO

Updated: 8:24 PM CDT

Temperature: 86.4 °F Dew Point: 74 °F Humidity: 66% Wind: Calm Pressure: 29.94 in Hourly Precipitation: - Heat Index: 94 °F Graphs

Location: Liberty Place, Troy, IL

Updated: 8:32 PM CDT

Temperature: 81.3 °F Dew Point: 72 °F Humidity: 73% Wind: SE at 3.0 mph Pressure: 29.40 in Hourly Precipitation: 0.00 in Heat Index: 86 °F Graphs

Location: Hamel, IL 55/140, Worden, IL

Updated: 8:38 PM CDT

Temperature: 81.0 °F Dew Point: 71 °F Humidity: 72% Wind: SSE at 2.7 mph Pressure: 28.53 in Hourly Precipitation: 0.00 in Heat Index: 85 °F Graphs

MSN Maps of:

Temp: Dew Point: Humidity Wind Pressure Hr Precip -

NWS Forecaster Discussion




Area forecast discussion...updated aviation 
National Weather Service St Louis MO 
708 PM CDT Tue Jul 22 2014 


Short term: (through late tonight) 
issued at 330 PM CDT Tue Jul 22 2014 


There is a considerable amount of uncertainty in the convective 
evolution and coverage tonight. Dew points in the 70s, strong 
heating and steep mid level lapse rates are currently contributing 
to SBCAPE of 3500-6000 j/kg across the northwest 2/3rds of the County Warning Area 
with the highest values across central and north central MO. There 
also is a significant cap in place due to warm mid level temperatures. 
The big question is when and how much of the cap will be reduced 
as the front moves southward out of Iowa and southeast Nebraska 
into northern MO this evening. Model solutions including the 
convection allowing models are quite varied on quantitative precipitation forecast and implied 
coverage. Recent runs of the hrrr are quite stingy on coverage 
with isolated storms at best. I don't have a great feel for what 
is going to occur, but the deterministic models suggest that height 
falls/cooling aloft should be sufficient to weaken the cap and 
allow for scattered development along front, mainly late this 
evening and especially overnight. I have attempted to follow this 
trend with the greatest coverage along/east of the MS river. The 
severe threat is conditional on development early enough this 
evening to realize the big cape, and the main threat would appear 
to be damaging winds given the warm air aloft. 


Glass 


Long term: (wednesday through next tuesday) 
issued at 330 PM CDT Tue Jul 22 2014 


The cold front should lie roughly from south central Illinois to near 
St. Louis into southwest MO at 12z and exit the County Warning Area by early 
afternoon. There will continue to be a threat of scattered showers 
and storms ahead of the advancing front. Temperatures should be 
cooler tomorrow with the main thrust of cooling and drying in the 
afternoon. Unseasonably deep upper troffing in the eastern U.S. 
Will keep a large surface high dominating the area Wednesday night 
into Friday, with most of this period dominated by lower humidity 
and below average temperatures. 


Beginning late Thursday night and into Friday the threat of precipitation 
will return in association with elevated showers/thunderstorms due to 
strong warm advection/moisture transport via a southwesterly low level jet ahead 
of the slowly retreating warm front and in association with impulses 
aloft dropping southeastward along the eastern periphery of the 
upper high. A cold front will then drop through the area Saturday 
afternoon-Sunday as a upper trof digs southeastward from the upper 
MS valley and into the Great Lakes bringing another threat of 
showers and thunderstorms. This upper wave will be part of large 
scale amplification of the upper air pattern across noam and will 
feature another deep trof over the eastern U.S. Through the first 
part of next week and send out July with another period of below 
average temperatures. 


Glass 


&& 


Aviation: (for the 00z tafs through 00z Wednesday evening) 
issued at 647 PM CDT Tue Jul 22 2014 


Focus remains on thunder potential this evening into the overnight 
and possible MVFR cigs Wednesday morning. Storms are expected to 
form along a cold front that currently stretches from ern Iowa into 
northwest MO then into NE Kansas. Tstms are fcst to dvlp later this evng and 
push slowly southeast. Think storms will eventually dvlp...but not 
confident on coverage or any particular cell impacting one of the 
terminals. The front is relatively weak and moving slowly...so it 
will take most of the night for it to clear the terminals. This 
means that storms may take longer to clear a terminal than is 
currently indicated. Tstms are expected to dvlp along the front 
again tomorrow aftn/evng...but should be well south of the 
terminals by then. There is the potential for some Post frontal 
high end MVFR stratus/stratocu Wednesday morning. If it 
dvlps...should not last long...burning off by mid/late mrng. If 
any terminal gets rain this evng or overnight...there is the 
potential for fog by morning as the bndry lyr remains quite moist 
behind the front...esp if the expected low clouds do not form. 
Beyond tomorrow morning...diurnal cu and a north/north-northeast breeze as high 
pressure builds into the region. 


Specifics for kstl: 


Possible for tstms overnight...but not sure of the coverage. There 
is the potential for storms to remain near the terminal later than 
indicated based on the slow mvmnt of the front. Models indicate 
the potential for high end MVFR clouds towards 12z...but again not 
confident on this scenario. If the terminal did get rain...then 
fog might be possible given the moist bndry layer behind the 
front...esp if the lower clouds do not form. 


2% 


&& 


Lsx watches/warnings/advisories: 
MO...none. 
Illinois...none. 
&& 


$$ 


Weather forecast office lsx 



National Weather Service Glossary of Abbreviations

Non-Expanded Version (with abbreviations)

Powered by the Weather Underground, Inc.