Dekalb, Illinois Weather Conditions

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Current Conditions

  • 61°
  • Clear
  • Wind: WSW 5 mph
  • Humidity: 89%
  • Visibility: 10.0 miles
  • Dew Point: 58°
  • Pressure: 30.01 in. +

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Next 12 Hours

1  am
4  am
7  am
10  am
1  pm
Fog
Fog
Fog
Fog
Fog
Fog
Clear
Clear
Partly Cloudy
Partly Cloudy
63°
61°
57°
70°
79°
Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Wednesday
  • Partly Cloudy
  • High: 82 °
  • Low: 66 °
  • Partly Cloudy
  • Thursday
  • Chance of a Thunderstorm
  • High: 86 °
  • Low: 68 °
  • Chance of a Thunderstorm
  • Friday
  • Chance of a Thunderstorm
  • High: 73 °
  • Low: 57 °
  • Chance of T-Storms
  • Saturday
  • Partly Cloudy
  • High: 72 °
  • Low: 50 °
  • Partly Cloudy
  • Sunday
  • Clear
  • High: 72 °
  • Low: 48 °
  • Clear

Forecast for Dekalb, Illinois

Updated: 10:00 PM CDT on September 02, 2014

  • Wednesday

    Partly cloudy. Fog early. High of 82F. Winds from the SSW at 5 to 15 mph.

  • Wednesday Night

    Partly cloudy with a chance of a thunderstorm and a chance of rain after midnight. Low of 66F. Winds from the South at 10 to 15 mph. Chance of rain 30%.

  • Thursday

    Partly cloudy with a chance of a thunderstorm and a chance of rain. High of 86F. Breezy. Winds from the SSW at 15 to 20 mph with gusts to 30 mph. Chance of rain 20%.

  • Thursday Night

    Partly cloudy with a chance of a thunderstorm and a chance of rain after midnight. Low of 68F. Winds from the SW at 5 to 15 mph. Chance of rain 30%.

  • Friday

    Partly cloudy with a chance of a thunderstorm and a chance of rain. Fog early. High of 73F. Winds from the NNW at 10 to 15 mph. Chance of rain 40%.

  • Friday Night

    Partly cloudy with a chance of rain. Low of 57F. Winds from the NNE at 5 to 10 mph.

  • Saturday

    Overcast in the morning, then partly cloudy. High of 72F. Winds from the NE at 5 to 10 mph.

  • Saturday Night

    Mostly cloudy in the evening, then clear. Low of 50F. Winds from the NE at 5 to 10 mph.

  • Sunday

    Clear. High of 72F. Winds from the NE at 5 to 10 mph.

  • Sunday Night

    Clear. Low of 48F. Winds from the ESE at 5 to 10 mph.

  • Monday

    Partly cloudy. High of 72F. Winds from the SE at 5 to 10 mph.

  • Monday Night

    Mostly cloudy. Fog overnight. Low of 55F. Winds from the SE at 5 to 10 mph.

  • Tuesday

    Overcast with a chance of a thunderstorm. High of 73F. Winds from the SSE at 5 to 10 mph. Chance of rain 50%.

  • Tuesday Night

    Overcast with thunderstorms. Fog overnight. Low of 63F. Winds from the South at 5 to 10 mph. Chance of rain 70% with rainfall amounts near 1.0 in. possible.

  • Wednesday

    Overcast with a chance of a thunderstorm. Fog early. High of 75F. Winds from the SSW at 5 to 10 mph. Chance of rain 40%.

  • Wednesday Night

    Mostly cloudy with a chance of a thunderstorm. Fog overnight. Low of 59F. Winds less than 5 mph. Chance of rain 40%.

  • Thursday

    Mostly cloudy with a chance of a thunderstorm. Fog early. High of 73F. Winds less than 5 mph. Chance of rain 50%.

  • Thursday Night

    Mostly 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 0.2 in. possible.

  • Friday

    Mostly cloudy with a chance of a thunderstorm. Fog early. High of 70F. Winds less than 5 mph. Chance of rain 50%.

  • Friday Night

    Overcast with a chance of a thunderstorm. Fog overnight. Low of 54F. Winds less than 5 mph. Chance of rain 60% with rainfall amounts near 1.1 in. possible.

  • Saturday

    Clear with a chance of a thunderstorm. Fog early. High of 72F. Winds less than 5 mph. Chance of rain 40%.

  • Saturday Night

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

Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: South DeKalb, DeKalb, IL

Updated: 1:57 AM CDT

Temperature: 59.8 °F Dew Point: 58 °F Humidity: 95% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Graphs

Location: Northern Illinois University, DeKalb, IL

Updated: 1:57 AM CDT

Temperature: 62.1 °F Dew Point: 58 °F Humidity: 88% Wind: Calm Pressure: 29.88 in Hourly Precipitation: 0.00 in Graphs

Location: Rob's Horsepower Haven, DeKalb, IL

Updated: 1:54 AM CDT

Temperature: 61.6 °F Dew Point: 60 °F Humidity: 93% Wind: Calm Pressure: 29.94 in Hourly Precipitation: 0.00 in Graphs

Location: DeKalb, IL

Updated: 1:43 AM CDT

Temperature: 62.2 °F Dew Point: 60 °F Humidity: 92% Wind: Calm Pressure: 29.93 in Hourly Precipitation: - Graphs

Location: MesoWest MALTA1 IL US UPR, Malta, IL

Updated: 1:10 AM CDT

Temperature: 62 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: MesoWest IL-64 @ Virgil Drainage Ditch IL US ILDOT, Sycamore, IL

Updated: 1:26 AM CDT

Temperature: 59 °F Dew Point: 59 °F Humidity: 98% Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Heron Creek, Sycamore, IL

Updated: 1:57 AM CDT

Temperature: 60.4 °F Dew Point: 59 °F Humidity: 96% Wind: Calm Pressure: 29.99 in Hourly Precipitation: 0.00 in Graphs

Location: OG Heron Creek, Sycamore, IL

Updated: 1:57 AM CDT

Temperature: 60.4 °F Dew Point: 60 °F Humidity: 97% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Graphs

Location: The Rockin' N, Waterman, IL

Updated: 1:57 AM CDT

Temperature: 76.1 °F Dew Point: - Humidity: - Wind: North at - Pressure: 29.95 in Hourly Precipitation: - Graphs

Location: CRN NIU AGRONOMY SHABONNA 5 NNE IL US, Shabbona, IL

Updated: 1:00 AM CDT

Temperature:  °F Dew Point: - Humidity: 94% Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Out On the Farm, Clare, IL

Updated: 1:51 AM CDT

Temperature: 58.2 °F Dew Point: 57 °F Humidity: 95% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Graphs

Location: Country Meadows, Kirkland, IL

Updated: 1:53 AM CDT

Temperature: 58.6 °F Dew Point: 57 °F Humidity: 93% Wind: Calm Pressure: 29.92 in Hourly Precipitation: 0.00 in Graphs

Location: Genoa Road, Genoa, IL

Updated: 1:54 AM CDT

Temperature: 61.3 °F Dew Point: 60 °F Humidity: 96% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Graphs

Location: Columbine Square, Elburn, IL

Updated: 1:53 AM CDT

Temperature: 59.5 °F Dew Point: 59 °F Humidity: 97% Wind: Calm Pressure: 29.91 in Hourly Precipitation: 0.00 in Graphs

Location: Prairie Highlands, Elburn, IL

Updated: 1:55 AM CDT

Temperature: 63.8 °F Dew Point: 60 °F Humidity: 89% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Graphs

Location: Cheval-De-Selle, Elburn, IL

Updated: 1:51 AM CDT

Temperature: 57.2 °F Dew Point: 55 °F Humidity: 93% Wind: Calm Pressure: 29.90 in Hourly Precipitation: - Graphs

Location: MesoWest I-39 @ MP 81 / Lee County IL US ILDOT, Steward, IL

Updated: 1:26 AM CDT

Temperature: 60 °F Dew Point: 59 °F Humidity: 96% Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Hampshire, IL, Hampshire, IL

Updated: 1:57 AM CDT

Temperature: 60.4 °F Dew Point: 58 °F Humidity: 90% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Graphs

Location: K9GPC, Rochelle, IL

Updated: 1:57 AM CDT

Temperature: 63.3 °F Dew Point: 62 °F Humidity: 96% Wind: Calm Pressure: 29.23 in Hourly Precipitation: 0.00 in Graphs

Location: CamptonHillsWeather.com Central Kane County, St Charles, IL

Updated: 1:57 AM CDT

Temperature: 61.7 °F Dew Point: 60 °F Humidity: 94% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Graphs

Location: OakGrove, Hampshire, IL

Updated: 1:43 AM CDT

Temperature: 60.1 °F Dew Point: 59 °F Humidity: 97% Wind: Calm Pressure: 29.88 in Hourly Precipitation: - Graphs

Location: Geneva, IL

Updated: 1:56 AM CDT

Temperature: 62.8 °F Dew Point: 60 °F Humidity: 90% Wind: Calm Pressure: 29.91 in Hourly Precipitation: 0.00 in Graphs

Location: Windswept Acres, Marengo, IL

Updated: 1:55 AM CDT

Temperature: 60.7 °F Dew Point: 60 °F Humidity: 99% Wind: Calm Pressure: 29.93 in Hourly Precipitation: 0.00 in Graphs

Location: Hidden Farms Estates, Marengo, IL

Updated: 1:56 AM CDT

Temperature: 58.7 °F Dew Point: 56 °F Humidity: 89% Wind: Calm Pressure: 29.97 in Hourly Precipitation: 0.00 in Graphs

Location: Mill Creek, Geneva, IL

Updated: 1:49 AM CDT

Temperature: 61.4 °F Dew Point: 60 °F Humidity: 96% Wind: Calm Pressure: 29.91 in Hourly Precipitation: 0.00 in Graphs

Location: Mill Creek (NE), Geneva, IL

Updated: 1:57 AM CDT

Temperature: 60.3 °F Dew Point: 59 °F Humidity: 95% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Graphs

Location: WB9NJJ, Rochelle, IL

Updated: 1:57 AM CDT

Temperature: 57.7 °F Dew Point: 50 °F Humidity: 74% Wind: Calm Pressure: 29.70 in Hourly Precipitation: 0.00 in Graphs

Location: Thornwood, South Elgin, IL

Updated: 1:50 AM CDT

Temperature: 59.4 °F Dew Point: 58 °F Humidity: 95% Wind: Calm Pressure: 29.85 in Hourly Precipitation: - Graphs

Location: Plano, Plano, IL

Updated: 1:52 AM CDT

Temperature: 63.0 °F Dew Point: 61 °F Humidity: 93% Wind: Calm Pressure: 29.93 in Hourly Precipitation: 0.00 in Graphs

Location: Creek Side, Elgin, IL

Updated: 1:41 AM CDT

Temperature: 60.7 °F Dew Point: 57 °F Humidity: 89% Wind: Calm Pressure: 29.08 in Hourly Precipitation: 0.00 in Graphs

Location: Waterford Oaks, North Aurora, IL

Updated: 1:57 AM CDT

Temperature: 63.8 °F Dew Point: 62 °F Humidity: 94% Wind: Calm Pressure: 29.95 in Hourly Precipitation: 0.00 in Graphs

Location: West Batavia, Batavia, IL

Updated: 1:55 AM CDT

Temperature: 62.5 °F Dew Point: 61 °F Humidity: 95% Wind: Calm Pressure: 29.92 in Hourly Precipitation: - Graphs

Location: Dover Ridge, Geneva, IL

Updated: 1:57 AM CDT

Temperature: 62.4 °F Dew Point: 60 °F Humidity: 93% Wind: Calm Pressure: 29.94 in Hourly Precipitation: 0.00 in Graphs

Location: Rural--2.75 mi WSW Sandwich, IL, Sandwich, IL

Updated: 1:49 AM CDT

Temperature: 64.2 °F Dew Point: 61 °F Humidity: 88% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Graphs

Location: Gilberts, IL, Gilberts, IL

Updated: 1:57 AM CDT

Temperature: 60.3 °F Dew Point: 59 °F Humidity: 96% Wind: Calm Pressure: 30.18 in Hourly Precipitation: 0.00 in Graphs

Location: Belvidere, Belvidere, IL

Updated: 1:50 AM CDT

Temperature: 59.4 °F Dew Point: 59 °F Humidity: 98% Wind: Calm Pressure: 29.73 in Hourly Precipitation: - Graphs

Location: MesoWest I-39 @ Kishwaukee River Bridge IL US ILDOT, Rockford, IL

Updated: 1:26 AM CDT

Temperature: 62 °F Dew Point: 59 °F Humidity: 90% Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

MSN Maps of:

Temp: Dew Point: Humidity Wind Pressure Hr Precip -

NWS Forecaster Discussion




Area forecast discussion 
National Weather Service Chicago/Romeoville Illinois 
1204 am CDT Wednesday Sep 3 2014 


Discussion... 
324 PM CDT 


Cold front which moved through the forecast area last night has 
settled into the Ohio River valley this afternoon...with weak high 
pressure center developing eastward from the lower Missouri Valley. 
Modest west-southwest low level winds were noted across the County Warning Area... 
several weak convergent zones including an outflow boundary from 
morning thunderstorms over northwest Illinois...the lake breeze boundary 
along the Illinois shore and extending east across northern 
Indiana...and a subtle trough axis/moisture gradient across our 
southeastern counties. Visible satellite imagery has shown cumulus/towering cumulus 
development along these boundaries at times with a few isolated 
showers having formed along the boundaries across far east central 
Illinois and Northwest Indiana. Another weak convergence axis was from 
near Milwaukee back into northwest Illinois...also with some cumulus 
development along it. While an isolated shower will be possible 
along any of these boundaries during the remainder of the afternoon 
hours...the higher surface dew point and MLCAPE axis over the far 
southeastern County Warning Area will have the best chance (and only isolated 
coverage at that) of any more significant showers or isolated 
thunder. Loss of diurnal instability should end isolated precipitation 
threat by early evening. Weak surface pressure gradient north of 
surface high pressure center will allow for light winds overnight... 
and with mainly clear skies should see some patchy fog develop 
especially across areas south of Chicago where dew point temperatures will 
be a little higher and where ground likely remains moist from recent 
heavy rains. 


Attention then turns toward the west Wednesday...as surface low 
pressure development takes place across the High Plains in response 
to strong middle-level short wave crossing the northern rockies. 
Guidance has trended deeper with the middle-level wave and the 
resulting surface low...with southerly return flow developing and 
strengthening across the Mississippi Valley and western lakes region 
by later Wednesday and Wednesday night. This will result in the cold 
front to our south returning north as a warm front Wednesday 
night...and bringing very warm/hot and humid conditions back for 
Thursday and Friday. Thunderstorm potential increases Wednesday 
night and early Thursday as the warm front pushes north...before 
capping inversion develops in 900-700 mb layer within warm sector 
Thursday. Hot and humid conditions expected Thursday...with 850 mb 
temperatures in excess of +20 c and 950 mb temperatures approaching +28 c. 
Provided that any morning clouds/precipitation with early morning warm 
frontal passage scatter...and no significant convective outflow 
remains...afternoon highs around 90/lower 90s look reasonable. 
Combined with dew point temperatures climbing into the 70s... heat index 
values of 95-105 would make for uncomfortable conditions. 


Deep surface low continues to deepen as it moves east across Ontario 
Thursday night...with a trailing cold front pushing into northern 
Illinois pre-dawn Friday. Shower/thunderstorm potential increases 
early Friday with arrival of front...and continues through Friday 
night as front sags south into downstate IL/in. With front 
bisecting County Warning Area during the day...a fairly large temperature spread is 
anticipated with upper 70s/low 80s along the Wisconsin border...and 
upper 80s/near 90 again across the southern counties of the forecast 
area with most of the cloud cover and precipitation expected along/north of 
the advancing front as capping remains in place south of the 
boundary. 


Broad surface high pressure then spreads across the upper Midwest 
and Great Lakes region Saturday and Sunday...with dry and much 
cooler conditions with easterly low level flow and lake breezes. 
Next chance of organized precipitation appears to arrive at the end of the 
forecast period on Tuesday. 


Ratzer 


&& 


Aviation... 


//Ord and mdw concerns...updated 06z... 


* very small threat of a short period of thunderstorms late 
Wednesday night into early Thursday morning. 


* None. 


Kjb 


//discussion...updated 06z... 


Light winds under a surface ridge of high pressure will likely 
allow for the development for at least some patchy fog again across 
portions of the area overnight. Therefore...this is the main 
aviation concern this morning. However...this fog should not 
impact kmdw or kord. 


Winds will turn southerly during the day today as the surface high 
shifts towards the East Coast. These southerly winds will likely 
remain elevated Wednesday night into Thursday as a Stout area of 
low pressure moves eastward across the Dakotas. This should set 
the stage for thunderstorms across much of the upper Midwest and 
into Wisconsin Wednesday night into Thursday. There is a small 
chance (~20%) that a few of storms could try to shift 
southeastward into far northern Illinois late Wednesday night into 
early Thursday morning before weakening. However...it appears the 
main threat will by far remain north of the area in Wisconsin...so 
I will hold off on introducing any showers or storms at this time. 


Kjb 




//Ord and mdw confidence...updated 06z... 


* low on any storms impacting the terminals late Wednesday night. 


* High for all other elements. 


Kjb 


//outlook for Ord/mdw for 12z Thursday-12z Tuesday...updated 00z... 


Thursday...chance of morning thunderstorms and rain. 


Friday...chance of thunderstorms and rain. 


Saturday through Monday...VFR with northeast to east winds. 


Tuesday...chance thunderstorms and rain. 


Kmd 


&& 


Marine... 
251 PM CDT 


Main forecast concern is with strong southerly winds ahead of 
deepening low pressure moving from the northern plains on Thursday 
to James Bay by Friday morning. Tightening pressure gradient and 
pressure falls will result in strengthening southerly flow during 
the day Wednesday and especially Wednesday night. Sustained winds 
will peak on Thursday in the lower 20 knots range...but have lower 
confidence in gust speeds due warm air mass overspreading the 
region. Will continue to mention 30 knots gusts in the Gulf. Its 
possible that near shore waters could see more frequent gusts up to 
30 knots in strong offshore flow...with forecast soundings indicating 
that potential. Small Craft Advisory winds are likely Thursday 
morning into Thursday evening for the entire nearshore. 


Then a strong cold front trailing from the low pressure area will 
sweep down the lake Thursday night through Friday afternoon. A 
period of decent northerly winds could set up especially on the 
southern half of the lake...but high pressure will quickly spread 
eastward and reduce speeds. Therefore...it is uncertain whether 
duration of northerly winds will be sufficient to result in waves 
building to Small Craft Advisory criteria. For now do have waves 
above criteria in grids. Winds will become relatively light over 
the weekend with expansive high pressure slowly sliding 
eastward...though northerly. 


Rc 


&& 


Lot watches/warnings/advisories... 
Illinois...none. 
In...none. 
Lm...none. 
&& 


$$ 


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