Skip to main content
One weather site to rule them all
checkweather.io
CheckWeather US›Illinois›Upper Alton

Upper Alton weather

Loading live data…

CheckWeather.io on iPhoneFree. No ads, no account.

Upper Alton weather alerts and warnings

active National Weather Service watches, warnings and advisories

Checking the National Weather Service for active alerts covering Upper Alton…

Upper Alton weather in numbers

measured normals and 10 years of recorded weather

Upper Alton swings 63°F across the year, from 87°F highs in July to 24°F lows in January, and May is usually the wettest month in a year that brings about 44 in of precipitation. Over 10 years of recorded weather it averages 136 days a year at 77°F or above, 59 of them at 86°F or above, 78 frost nights, and rain on 126 days.

Warmest month
July
87°F average high
Coldest month
January
24°F average low
Wettest month
May
44 in a year
Comfortable
3 months
April, September and October
Residents
29,000
share this forecast
Most accurate here
European
93/100 CheckWeather Score
Warm days
136 days
a year at 77°F or above
Frost nights
78 nights
a year below 32°F
Rain days
126 days
a year with 0.04 in or more

Day counts are from the ERA5 reanalysis for Upper Alton’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.

The weather map: all three models at once

NWS, American, European side by side around Upper Alton and nearby towns.Live rain radar →
Loading the three model maps…

Upper Alton hourly forecast: next 14 hours

consensus of the three models

Rain in the next 24 hours, model by model

each model's own hourly precipitation, side by side

Loading the three models…

Upper Alton 10-day forecast, out to 14 days

where the models agree, and where they split

Upper Alton, Illinois (IL) is at its warmest in Jul (average highs near 87°F) and coldest in Jan (lows around 24°F), with roughly 44 in of precipitation across the year. Below, compare what NWS, American, European forecast for Upper Alton right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

Upper Alton climate by month

average daytime high and overnight low across a typical year (1991-2020)
Jan
38°
24°
Feb
46°
26°
Mar
54°
35°
Apr
66°
46°
May
77°
57°
Jun
84°
64°
Jul
87°
70°
Aug
84°
68°
Sep
77°
60°
Oct
66°
48°
Nov
52°
37°
Dec
42°
29°

Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.

How Upper Alton's weather has changed since 1995

30 years of daily data, 1995-2024, shown as change
+1.1°F

Around Upper Alton, the difference between 1995-2004 and 2015-2024 is +1.1°F, within the normal swing from year to year.

1995: −1.8°F vs the 30-year average1996: −2.3°F vs the 30-year average1997: −1.4°F vs the 30-year average1998: +1.3°F vs the 30-year average1999: +0.8°F vs the 30-year average2000: −0.7°F vs the 30-year average2001: +0.8°F vs the 30-year average2002: −0.1°F vs the 30-year average2003: −0.7°F vs the 30-year average2004: −0.3°F vs the 30-year average2005: +0.9°F vs the 30-year average2006: +1.5°F vs the 30-year average2007: +1.3°F vs the 30-year average2008: −2.5°F vs the 30-year average2009: −1.6°F vs the 30-year average2010: −0.5°F vs the 30-year average2011: +0.2°F vs the 30-year average2012: +3.3°F vs the 30-year average2013: −1.9°F vs the 30-year average2014: −2.8°F vs the 30-year average2015: ±0.0°F vs the 30-year average2016: +1.3°F vs the 30-year average2017: +2.0°F vs the 30-year average2018: −0.3°F vs the 30-year average2019: −0.7°F vs the 30-year average2020: −0.3°F vs the 30-year average2021: +0.6°F vs the 30-year average2022: −0.7°F vs the 30-year average2023: +2.6°F vs the 30-year average2024: +2.4°F vs the 30-year average
1995each stripe is one year2024
cooler than averagearound averagewarmer than average

Days above 95°F

4 fewer days a year

2015-2024 against 1995-2004. Within the normal year-to-year swing

1995: −8 vs the 30-year average1996: −4 vs the 30-year average1997: +0 vs the 30-year average1998: −6 vs the 30-year average1999: +12 vs the 30-year average2000: +0 vs the 30-year average2001: +9 vs the 30-year average2002: −2 vs the 30-year average2003: +5 vs the 30-year average2004: −7 vs the 30-year average2005: +10 vs the 30-year average2006: +12 vs the 30-year average2007: +11 vs the 30-year average2008: −8 vs the 30-year average2009: −8 vs the 30-year average2010: −8 vs the 30-year average2011: −2 vs the 30-year average2012: +32 vs the 30-year average2013: −3 vs the 30-year average2014: −6 vs the 30-year average2015: −8 vs the 30-year average2016: −8 vs the 30-year average2017: +0 vs the 30-year average2018: −8 vs the 30-year average2019: −8 vs the 30-year average2020: −8 vs the 30-year average2021: −8 vs the 30-year average2022: −2 vs the 30-year average2023: +8 vs the 30-year average2024: −1 vs the 30-year average

Frost nights

10 fewer nights a year

2015-2024 against 1995-2004, below 32°F. Within the normal year-to-year swing

1995: +13 vs the 30-year average1996: +23 vs the 30-year average1997: +8 vs the 30-year average1998: −18 vs the 30-year average1999: −2 vs the 30-year average2000: +9 vs the 30-year average2001: +0 vs the 30-year average2002: +4 vs the 30-year average2003: +7 vs the 30-year average2004: −11 vs the 30-year average2005: −1 vs the 30-year average2006: −11 vs the 30-year average2007: +10 vs the 30-year average2008: +18 vs the 30-year average2009: −7 vs the 30-year average2010: −2 vs the 30-year average2011: −8 vs the 30-year average2012: −9 vs the 30-year average2013: +23 vs the 30-year average2014: +23 vs the 30-year average2015: −18 vs the 30-year average2016: −9 vs the 30-year average2017: −20 vs the 30-year average2018: +14 vs the 30-year average2019: +10 vs the 30-year average2020: −1 vs the 30-year average2021: −7 vs the 30-year average2022: +9 vs the 30-year average2023: −25 vs the 30-year average2024: −22 vs the 30-year average

Average wind

no clear change

2015-2024 against 1995-2004. Within the normal year-to-year swing

1995: −4% vs the 30-year average1996: +6% vs the 30-year average1997: −1% vs the 30-year average1998: −4% vs the 30-year average1999: +3% vs the 30-year average2000: +1% vs the 30-year average2001: −1% vs the 30-year average2002: −1% vs the 30-year average2003: +1% vs the 30-year average2004: +1% vs the 30-year average2005: −4% vs the 30-year average2006: +3% vs the 30-year average2007: −1% vs the 30-year average2008: +6% vs the 30-year average2009: +1% vs the 30-year average2010: −4% vs the 30-year average2011: +1% vs the 30-year average2012: +1% vs the 30-year average2013: +1% vs the 30-year average2014: +1% vs the 30-year average2015: −1% vs the 30-year average2016: −4% vs the 30-year average2017: +1% vs the 30-year average2018: −1% vs the 30-year average2019: +1% vs the 30-year average2020: −4% vs the 30-year average2021: −1% vs the 30-year average2022: +6% vs the 30-year average2023: −1% vs the 30-year average2024: +1% vs the 30-year average

Bars: each year against the area's 30-year average. Dashed lines: the average of the first and the last ten years.

See the numbers year by year
YearTemp vs averageDays >95°F vs avgFrost nights vs avgWind vs avg
1995−1.8°F−8+13−4%
1996−2.3°F−4+23+6%
1997−1.4°F+0+8−1%
1998+1.3°F−6−18−4%
1999+0.8°F+12−2+3%
2000−0.7°F+0+9+1%
2001+0.8°F+9+0−1%
2002−0.1°F−2+4−1%
2003−0.7°F+5+7+1%
2004−0.3°F−7−11+1%
2005+0.9°F+10−1−4%
2006+1.5°F+12−11+3%
2007+1.3°F+11+10−1%
2008−2.5°F−8+18+6%
2009−1.6°F−8−7+1%
2010−0.5°F−8−2−4%
2011+0.2°F−2−8+1%
2012+3.3°F+32−9+1%
2013−1.9°F−3+23+1%
2014−2.8°F−6+23+1%
2015±0.0°F−8−18−1%
2016+1.3°F−8−9−4%
2017+2.0°F+0−20+1%
2018−0.3°F−8+14−1%
2019−0.7°F−8+10+1%
2020−0.3°F−8−1−4%
2021+0.6°F−8−7−1%
2022−0.7°F−2+9+6%
2023+2.6°F+8−25−1%
2024+2.4°F−1−22+1%

Source: NASA POWER daily data from the MERRA-2 reanalysis, 1995-2024. Each value describes a grid square of about 50 km around Upper Alton, not a weather station, and a square that takes in sea or a large lake runs milder than the city itself. That is why this section shows change against the square's own 30-year average rather than counts you could compare with a local station. Rain and snow are left out because their long-term record in this dataset is not consistent over time. "Within the normal year-to-year swing" means the change is smaller than the usual differences between single years.

Which forecast is most accurate in Upper Alton?

CheckWeather Score, graded against the weather that actually happened
ProviderCheckWeather-scoreTempWindRainRun by
European logo
European ★ Best
93
/100rank #1
93±0.7°F98±0.6 mph8994% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
78
/100rank #2
78±2.2°F97±1.0 mph6581% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

What do you think of the forecasts?

your vote counts

The accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.

NWSNational Blend (NBM)
Loading ratings…
AmericanNOAA GFS
Loading ratings…
EuropeanECMWF
Loading ratings…

One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.

Common questions

What's the weather in Upper Alton today?
On this page we show what NWS, American, European each forecast for Upper Alton today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Upper Alton today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Upper Alton and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Upper Alton?
Over the last 30 days, the European model has been the most accurate for Upper Alton (CheckWeather Score 93/100), ahead of the American at 78. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Upper Alton?
July is typically the warmest month in Upper Alton, with average highs around 87°F.
How cold does Upper Alton get?
The coldest month in Upper Alton is January, when overnight lows average about 24°F.
How much rain does Upper Alton get?
Upper Alton sees roughly 44 in of precipitation a year, with May usually the wettest month.
Is Upper Alton getting warmer?
Not clearly. In NASA's reanalysis for the area around Upper Alton, the difference between 1995-2004 and 2015-2024 is 1.1°F, within the normal swing from year to year.

Nearby

AltonEast AltonGodfreyWood RiverBethaltoOld JamestownSpanish LakeBlack Jack

More US weather

Which forecast is most accurate in United States?US rain radarNWS vs American vs European: models comparedHow we measure forecast accuracyHow accurate is a 7-day forecast?Illinois weather todayAll US citiesHoliday weather abroadEmbed Upper Alton on your siteThe national forecast models, explained: NBM, UKMO, GEM and ACCESS