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WeatherLiveIllinoisGreater Grand CrossingMonthly Outlook

Greater Grand Crossing, IL Monthly Outlook

30-day outlook · Greater Grand Crossing

All 30 days, one strip

swipe sideways · tap a day for detail

30 days of temperature & precip

Greater Grand Crossing · first 14 days — live forecast · rest of month — climate corridor

🗺️ 14-day forecast map

Greater Grand Crossing & neighbors — hit play
Every city on the map carries real forecast data from the same models as its city page, refreshed several times a day. The icon is the day's overall look; the number is the afternoon high.

Next 14 days at a glance

from the model forecast
Hottest day
98°
Tue, Sep 1
Coldest night
54°
Wed, Sep 9
Days with precip
9 / 14
of 14 forecast days
Nicest day
Mon, Sep 14
mild, dry, light wind

The next 4 weekends

plan ahead
Sat 5 – Sun 6 Sep
84° 67°
77% precip chance
Sat 12 – Sun 13 Sep
83° 65°
84% precip chance
Sat 19 – Sun 20 Sep
81° 65°
typical range
Sat 26 – Sun 27 Sep
78° 65°
typical range

30 days — Greater Grand Crossing

14 forecast + 16 climatology

How does a 30-day outlook work?

The first 14 days are a live model forecast. The back half of the month shows the typical range for those dates — useful for planning, not a literal prediction.

First 14 days: a real forecast, blended from NBM, ECMWF and GFS runs. Trust it most inside three days; by the second week treat it as a lean, not a promise.

Rest of the month: past day 14 we stop pretending to forecast and switch to the climate corridor — the range those dates have produced over three decades computed directly for Greater Grand Crossing, with mild week-to-week wiggle.

Good question for this page: "Is late August usually humid in Chicago?" Bad question: "Do I need an umbrella on the 29th?" — three weeks out no one knows, and that's the honest answer.

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Updated: 12:07 PM