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CheckWeather USGranite City

Granite City weather

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Granite City weather alerts and warnings

active National Weather Service watches, warnings and advisories

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Granite City weather in numbers

from 30 years of measured normals

Granite City swings 61°F across the year, from 88°F highs in July to 27°F lows in January, and May is usually the wettest month in a year that brings about 45 in of precipitation.

Warmest month
July
88°F average high
Coldest month
January
27°F average low
Wettest month
May
45 in a year
Below freezing
1 month
January
Comfortable
2 months
April and October
Residents
29,000
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The weather map: all three models at once

NWS, American, European side by side around Granite City and nearby towns.Live rain radar →
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Granite City 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

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Granite City 10-day forecast, out to 14 days

where the models agree, and where they split

Granite City, Illinois (IL) is at its warmest in Jul (average highs near 88°F) and coldest in Jan (lows around 27°F), with roughly 45 in of precipitation across the year. Below, compare what NWS, American, European forecast for Granite City 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.

Granite City climate by month

average daytime high and overnight low across a typical year
Jan
42°
27°
Feb
54°
33°
Mar
58°
39°
Apr
69°
48°
May
79°
59°
Jun
86°
66°
Jul
88°
70°
Aug
85°
69°
Sep
81°
63°
Oct
70°
52°
Nov
57°
41°
Dec
48°
34°

Which forecast is most accurate in Granite City?

CheckWeather Score, graded against the weather that actually happened
ProviderCheckWeather-scoreTempWindRainRun by
European logo
European ★ Best
91
/100rank #1
94±0.6°F98±0.8 mph8290% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
78
/100rank #2
78±2.2°F96±1.4 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)
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AmericanNOAA GFS
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EuropeanECMWF
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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 Granite City today?
On this page we show what NWS, American, European each forecast for Granite City 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 Granite City today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Granite City 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 Granite City?
Over the last 30 days, the European model has been the most accurate for Granite City (CheckWeather Score 91/100), 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 Granite City?
July is typically the warmest month in Granite City, with average highs around 88°F.
How cold does Granite City get?
The coldest month in Granite City is January, when overnight lows average about 27°F.
How much rain does Granite City get?
Granite City sees roughly 45 in of precipitation a year, with May usually the wettest month.

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