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Big Flat Lake, IL Weather Forecast & Current Conditions

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Big Flat Lake Weather Map
UTC Time: 10/3/2026, 17:09
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Aeronautical Observation: Automated synoptic observations via NWS Gateway.
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Big Flat Lake, IL Regional Weather

Expires:202610031800;;471498
ASUS43 KLOT 031706
RWRIL 

ILLINOIS REGIONAL WEATHER ROUNDUP
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1200 PM CDT SAT OCT 03 2026

NOTE: "FAIR" INDICATES FEW OR NO CLOUDS BELOW 12,000 FEET WITH NO
SIGNIFICANT WEATHER AND/OR OBSTRUCTIONS TO VISIBILITY.

* THESE STATIONS ARE NOT UNDER NWS QUALITY CONTROL. THEY ALSO MAY NOT
  REPORT WEATHER SUCH AS PRECIPITATION OR FOG.


ILZ064>066-069>071-074>076-080>082-084>086-088>090-092>094-031800-
SOUTH-CENTRAL ILLINOIS
  
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS
CARBONDALE     SUNNY     70  55  60 NE8       30.22F TC  21           
CAIRO*         MOSUNNY   69  59  70 NE10      30.20F TC  20           
EFFINGHAM*     SUNNY     69  45  42 E12       30.27F TC  20           
MT. VERNON     SUNNY     70  46  42 NE10      30.24F TC  21           
CENTRALIA*     SUNNY     71  43  36 NE9       30.24F TC  22           
SALEM*         SUNNY     70  49  47 MISG      30.24F TC  21           
METROPOLIS*    MOSUNNY   70  56  59 NE7       30.20F TC  21           
$$


SKY/WX - Weather  TMP - Temperature  DP - Dew Point  RH - Humidity
WIND - Wind Direction/Speed  PRES - Barometric Pressure  VSB - Visibility
WCI - Wind Chill Index  E13G22 Wind - East Wind 13 mph/Gusts of 22 mph

Big Flat Lake, IL

Today
Sunny
75°/ 48° 24°/ 9°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Partly cloudy. Lows in the upper 40s. Northeast winds around 5 mph in the evening, becoming light and variable.

Centralia, IL

Today
Sunny
75°/ 48° 24°/ 9°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Partly cloudy. Lows in the upper 40s. Northeast winds around 5 mph in the evening, becoming light and variable.

Alton, IL

Today
Sunny
75°/ 50° 24°/ 10°
0%
Sunday
Sunny
78°/ 52° 26°/ 11°
0%
Monday
Sunny
75°/ 50° 24°/ 10°
0%
Tue Night
Clear
50°10°
0%
Wednesday
Sunny
82°/ 55° 28°/ 13°
0%
Thursday
Clear
85°29°
0%
Friday
Clear
85°29°
0%

Day: Sunny. Highs in the mid 70s. East winds around 5 mph.

Night: Partly cloudy in the evening, then clearing. Lows around 50. East winds around 5 mph in the evening, becoming light and variable.

Litchfield, IL

Today
Sunny
75°/ 45° 24°/ 7°
0%
Sunday
Sunny
78°/ 48° 26°/ 9°
0%
Monday
Sunny
72°/ 45° 22°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the mid 70s. East winds 5 to 10 mph.

Night: Partly cloudy in the evening, then becoming mostly clear. Lows in the mid 40s. East winds around 5 mph in the evening, becoming light and variable.

Mount Vernon, IL

Today
Sunny
75°/ 48° 24°/ 9°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 45° 24°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the upper 40s. Northeast winds around 5 mph in the evening, becoming light and variable.

Pinckneyville, IL

Today
Sunny
75°/ 50° 24°/ 10°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 45° 24°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows around 50. Northeast winds around 5 mph in the evening, becoming light and variable.

Chester, IL

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Clear
85°29°
0%
Thursday
Clear
85°29°
0%
Friday
Clear
85°29°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds around 5 mph.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Monroe County, IL

Today
Sunny
75°/ 50° 24°/ 10°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°/ 55° 28°/ 13°
0%
Friday
Sunny
85°29°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds around 5 mph.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows around 50. Northeast winds around 5 mph in the evening, becoming light and variable.

West Frankfort, IL

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 52° 26°/ 11°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Carbondale, IL

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 52° 26°/ 11°
0%
Monday
Sunny
72°/ 48° 22°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
80°/ 52° 27°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Greene County, IL

Today
Sunny
75°/ 45° 24°/ 7°
0%
Sunday
Sunny
78°/ 45° 26°/ 7°
0%
Monday
Sunny
72°/ 48° 22°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
82°/ 52° 28°/ 11°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the mid 70s. East winds around 5 mph.

Night: Mostly clear. Lows in the mid 40s. East winds around 5 mph in the evening, becoming light and variable.

Alton, MO

Today
Sunny
75°/ 50° 24°/ 10°
0%
Sunday
Sunny
78°/ 52° 26°/ 11°
0%
Monday
Sunny
75°/ 50° 24°/ 10°
0%
Tue Night
Clear
50°10°
0%
Wednesday
Sunny
82°/ 55° 28°/ 13°
0%
Thursday
Clear
85°29°
0%
Friday
Clear
85°29°
0%

Day: Sunny. Highs in the mid 70s. East winds around 5 mph.

Night: Partly cloudy in the evening, then clearing. Lows around 50. East winds around 5 mph in the evening, becoming light and variable.

Fairfield, IL

Today
Sunny
75°/ 48° 24°/ 9°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
72°/ 45° 22°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Partly cloudy. Lows in the upper 40s. Northeast winds around 5 mph in the evening, becoming light and variable.

Flora, IL

Today
Sunny
72°/ 48° 22°/ 9°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
72°/ 45° 22°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the lower 70s. East winds 5 to 10 mph.

Night: Partly cloudy. Lows in the upper 40s. Northeast winds around 5 mph.

McLeansboro, IL

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 52° 26°/ 11°
0%
Monday
Sunny
75°/ 45° 24°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Chester, MO

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Clear
85°29°
0%
Thursday
Clear
85°29°
0%
Friday
Clear
85°29°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds around 5 mph.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Herrin, IL

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
72°/ 48° 22°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Sunny
80°/ 52° 27°/ 11°
0%
Thursday
Clear
52°11°
0%
Friday
Clear
52°11°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows in the lower 50s. Northeast winds around 5 mph in the evening, becoming light and variable.

Jefferson County, MO

Today
Sunny
75°/ 50° 24°/ 10°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°/ 55° 28°/ 13°
0%
Friday
Sunny
85°29°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds around 5 mph.

Night: Mostly cloudy in the evening, then becoming partly cloudy. Lows around 50. Northeast winds around 5 mph in the evening, becoming light and variable.

Effingham, IL

Today
Sunny
72°/ 45° 22°/ 7°
0%
Sunday
Sunny
78°/ 48° 26°/ 9°
0%
Monday
Sunny
72°/ 45° 22°/ 7°
0%
Tue Night
Clear
45°7°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the lower 70s. East winds 5 to 10 mph.

Night: Partly cloudy. Lows in the mid 40s. Northeast winds around 5 mph.

Perryville, MO

Today
Sunny
75°/ 52° 24°/ 11°
0%
Sunday
Sunny
78°/ 50° 26°/ 10°
0%
Monday
Sunny
75°/ 48° 24°/ 9°
0%
Tue Night
Clear
48°9°
0%
Wednesday
Clear
82°28°
0%
Thursday
Clear
82°28°
0%
Friday
Clear
82°28°
0%

Day: Sunny. Highs in the mid 70s. Northeast winds 5 to 10 mph.

Night: Mostly cloudy. Lows in the lower 50s. Northeast winds around 5 mph, becoming north after midnight.

Names listed above may include county names.

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