Dekalb, Illinois Weather Conditions

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Current Conditions

  • 31°
  • Overcast
  • Wind: SSE 12 mph
  • Humidity: 92%
  • Visibility: 4.0 miles
  • Dew Point: 28°
  • Pressure: 30.17 in. +
  • Heat Index: 21

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Next 12 Hours

9  am
12  pm
3  pm
6  pm
9  pm
Fog
Fog
Overcast
Overcast
Overcast
Overcast
Overcast
Overcast
Overcast
Overcast
30°
32°
36°
34°
32°
Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Sunday
  • Overcast
  • High: 36 °
  • Low: 28 °
  • Overcast
  • Monday
  • Ice Pellets
  • High: 41 °
  • Low: 39 °
  • Ice Pellets
  • Tuesday
  • Chance of Rain
  • High: 43 °
  • Low: 28 °
  • Chance of Rain
  • Wednesday
  • Overcast
  • High: 34 °
  • Low: 23 °
  • Overcast
  • Thursday
  • Mostly Cloudy
  • High: 34 °
  • Low: 25 °
  • Mostly Cloudy

Forecast for Dekalb, Illinois

Updated: 9:00 AM CST on December 21, 2014

  • Sunday

    Overcast with ice pellets. Fog early. High of 36F with a windchill as low as 21F. Winds from the SSE at 10 to 15 mph.

  • Sunday Night

    Overcast. Low of 28F with a windchill as low as 21F. Breezy. Winds from the SSE at 10 to 20 mph.

  • Monday

    Overcast with ice pellets and a chance of snow, then rain and a chance of snow in the afternoon. High of 41F. Breezy. Winds from the SE at 15 to 20 mph. Chance of precipitation 80% .

  • Monday Night

    Overcast with rain. Low of 39F. Breezy. Winds from the SSE at 10 to 20 mph. Chance of rain 80% with rainfall amounts near 0.3 in. possible.

  • Tuesday

    Overcast with a chance of rain. High of 43F. Winds from the SSW at 5 to 10 mph. Chance of rain 30%.

  • Tuesday Night

    Overcast with a chance of snow. Fog overnight. Low of 28F. Winds from the WSW at 5 to 10 mph.

  • Wednesday

    Overcast. Fog early. High of 34F with a windchill as low as 23F. Winds from the NNW at 10 to 15 mph.

  • Wednesday Night

    Overcast. Low of 23F. Winds from the NW at 10 to 15 mph.

  • Thursday

    Mostly cloudy in the morning, then overcast. High of 34F with a windchill as low as 18F. Breezy. Winds from the SW at 10 to 20 mph.

  • Thursday Night

    Overcast. Fog overnight. Low of 25F with a windchill as low as 16F. Winds from the SSW at 5 to 15 mph.

  • Friday

    Overcast. High of 34F. Winds from the West at 5 to 15 mph shifting to the NNW in the afternoon.

  • Friday Night

    Overcast. Low of 19F. Winds from the NNW at 10 to 15 mph.

  • Saturday

    Clear. High of 27F with a windchill as low as 9F. Winds from the WNW at 5 to 15 mph.

  • Saturday Night

    Partly cloudy. Low of 14F with a windchill as low as 5F. Winds from the SW at 10 to 15 mph.

  • Sunday

    Partly cloudy. High of 16F with a windchill as low as -4F. Breezy. Winds from the NW at 15 to 20 mph.

  • Sunday Night

    Partly cloudy. Low of 10F. Winds from the West at 5 to 20 mph.

  • Monday

    Partly cloudy. High of 18F with a windchill as low as 1F. Winds from the West at 5 to 10 mph.

  • Monday Night

    Clear. Low of 7F with a windchill as low as -4F. Winds from the WNW at 5 to 10 mph.

  • Tuesday

    Clear. High of 9F with a windchill as low as -6F. Winds from the WNW at 10 to 15 mph.

  • Tuesday Night

    Clear. Low of 1F with a windchill as low as -9F. Winds from the WNW at 5 to 10 mph.

  • Wednesday

    Clear. High of 10F with a windchill as low as -8F. Winds from the West at 5 to 10 mph.

  • Wednesday Night

    Clear. Low of 1F. Winds from the West at 5 to 10 mph.

Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: South DeKalb, DeKalb, IL

Updated: 9:06 AM CST

Temperature: 31.9 °F Dew Point: 30 °F Humidity: 94% Wind: South at 2.0 mph Pressure: 30.19 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: DeKalb, IL

Updated: 9:05 AM CST

Temperature: 32.1 °F Dew Point: 31 °F Humidity: 95% Wind: SE at 10.0 mph Pressure: 30.18 in Hourly Precipitation: - Windchill: 24 °F Graphs

Location: Sycamore, IL

Updated: 9:05 AM CST

Temperature: 31.4 °F Dew Point: 30 °F Humidity: 94% Wind: South at 7.0 mph Pressure: 30.22 in Hourly Precipitation: 0.00 in Windchill: 25 °F Graphs

Location: Heron Creek, Sycamore, IL

Updated: 9:05 AM CST

Temperature: 31.8 °F Dew Point: 29 °F Humidity: 90% Wind: Calm Pressure: 30.16 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: OG Heron Creek, Sycamore, IL

Updated: 9:05 AM CST

Temperature: 31.8 °F Dew Point: 30 °F Humidity: 93% Wind: SE at 8.1 mph Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 25 °F Graphs

Location: Out On the Farm, Clare, IL

Updated: 9:05 AM CST

Temperature: 31.9 °F Dew Point: 30 °F Humidity: 94% Wind: SSE at 11.0 mph Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 23 °F Graphs

Location: Ellen Oaks Subdivision, Genoa, IL

Updated: 9:05 AM CST

Temperature: 32.0 °F Dew Point: 31 °F Humidity: 94% Wind: SSE at 8.0 mph Pressure: 30.21 in Hourly Precipitation: 0.00 in Windchill: 25 °F Graphs

Location: Country Meadows, Kirkland, IL

Updated: 8:51 AM CST

Temperature: 31.5 °F Dew Point: 30 °F Humidity: 92% Wind: SE at 6.0 mph Pressure: 30.15 in Hourly Precipitation: 0.00 in Windchill: 26 °F Graphs

Location: MesoWest ELBRN1 IL US UPR, Elburn, IL

Updated: 8:05 AM CST

Temperature: 33 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Windchill: 33 °F Graphs

Location: Genoa Road, Genoa, IL

Updated: 8:58 AM CST

Temperature: 33.1 °F Dew Point: 31 °F Humidity: 93% Wind: South at 7.0 mph Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 27 °F Graphs

Location: APRSWXNET Elburn IL US, Elburn, IL

Updated: 8:26 AM CST

Temperature: 32 °F Dew Point: 30 °F Humidity: 93% Wind: SSW at 1 mph Pressure: 30.21 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: Columbine, Elburn, IL

Updated: 8:52 AM CST

Temperature: 31.7 °F Dew Point: 30 °F Humidity: 92% Wind: SSE at 1.0 mph Pressure: 30.19 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: Columbine Square, Elburn, IL

Updated: 8:59 AM CST

Temperature: 31.6 °F Dew Point: 30 °F Humidity: 92% Wind: SE at 1.0 mph Pressure: 30.17 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: Prairie Highlands, Elburn, IL

Updated: 9:05 AM CST

Temperature: 33.1 °F Dew Point: 31 °F Humidity: 93% Wind: SE at 1.0 mph Pressure: 30.21 in Hourly Precipitation: 0.00 in Windchill: 33 °F Graphs

Location: Griffith Avenue, Elburn, IL

Updated: 9:01 AM CST

Temperature: 32.2 °F Dew Point: 30 °F Humidity: 92% Wind: North at - Pressure: 29.40 in Hourly Precipitation: - Windchill: 32 °F Graphs

Location: Hampshire, IL, Hampshire, IL

Updated: 9:05 AM CST

Temperature: 31.9 °F Dew Point: 29 °F Humidity: 89% Wind: SSE at 9.0 mph Pressure: 30.23 in Hourly Precipitation: 0.00 in Windchill: 24 °F Graphs

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

Updated: 9:05 AM CST

Temperature: 31.7 °F Dew Point: 30 °F Humidity: 92% Wind: South at 1.0 mph Pressure: 30.22 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: OakGrove, Hampshire, IL

Updated: 9:01 AM CST

Temperature: 31.8 °F Dew Point: 32 °F Humidity: 99% Wind: SSE at 4.2 mph Pressure: 30.06 in Hourly Precipitation: - Windchill: 28 °F Graphs

Location: Campton Hills, Campton Hills, IL

Updated: 9:05 AM CST

Temperature: 32.7 °F Dew Point: 31 °F Humidity: 92% Wind: SE at 6.0 mph Pressure: 30.24 in Hourly Precipitation: 0.00 in Windchill: 27 °F Graphs

Location: Windswept Acres, Marengo, IL

Updated: 9:05 AM CST

Temperature: 32.8 °F Dew Point: 31 °F Humidity: 94% Wind: SSE at 7.0 mph Pressure: 30.18 in Hourly Precipitation: 0.00 in Windchill: 26 °F Graphs

Location: Mill Creek, Geneva, IL

Updated: 8:55 AM CST

Temperature: 32.2 °F Dew Point: 29 °F Humidity: 89% Wind: SW at 2.0 mph Pressure: 30.17 in Hourly Precipitation: 0.00 in Windchill: 32 °F Graphs

Location: Mill Creek (NE), Geneva, IL

Updated: 9:05 AM CST

Temperature: 33.4 °F Dew Point: 31 °F Humidity: 89% Wind: South at 5.0 mph Pressure: 30.27 in Hourly Precipitation: 0.00 in Windchill: 29 °F Graphs

Location: 3 Lakes, St. Charles, IL

Updated: 7:13 AM CST

Temperature: 31.9 °F Dew Point: 29 °F Humidity: 90% Wind: North at 4.3 mph Pressure: 29.98 in Hourly Precipitation: - Windchill: 28 °F Graphs

Location: Paw Paw, Il, Paw Paw, IL

Updated: 8:18 AM CST

Temperature: 32.0 °F Dew Point: 31 °F Humidity: 95% Wind: SE at 4.0 mph Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 28 °F Graphs

Location: WB9NJJ, Rochelle, IL

Updated: 9:05 AM CST

Temperature: 32.9 °F Dew Point: 22 °F Humidity: 63% Wind: SE at 6.0 mph Pressure: 29.85 in Hourly Precipitation: 0.00 in Windchill: 27 °F Graphs

Location: Sweetbriar Place, Plano, IL

Updated: 8:40 AM CST

Temperature: 36.0 °F Dew Point: 29 °F Humidity: 76% Wind: North at - Pressure: 30.27 in Hourly Precipitation: - Windchill: 36 °F Graphs

Location: Plano, Plano, IL

Updated: 8:58 AM CST

Temperature: 33.3 °F Dew Point: 31 °F Humidity: 90% Wind: Calm Pressure: 30.19 in Hourly Precipitation: 0.00 in Windchill: 33 °F Graphs

Location: Waterford Oaks, North Aurora, IL

Updated: 9:05 AM CST

Temperature: 33.2 °F Dew Point: 30 °F Humidity: 90% Wind: SSE at 7.0 mph Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 27 °F Graphs

Location: West Batavia, Batavia, IL

Updated: 9:04 AM CST

Temperature: 32.7 °F Dew Point: 30 °F Humidity: 89% Wind: Calm Pressure: 30.18 in Hourly Precipitation: - Windchill: 33 °F Graphs

MSN Maps of:

Temp: Dew Point: Humidity Wind Pressure Hr Precip -

NWS Forecaster Discussion




Area forecast discussion 
National Weather Service Chicago/Romeoville Illinois 
804 am CST sun Dec 21 2014 


Short term... 
620 am CST 


The main concerns during this period will mainly be focused on 
the timing of rainfall expected Monday and Monday night. 


Warm air advection/isentropic ascent has produced some drizzle and 
even some occasional light snow/flurries across portions of north 
central Illinois early this morning. Temperatures across the area 
continue to hold steady either right at freezing or a degree or two 
below in some areas. Therefore...there will continue to be threat 
for some minor glazing on untreated surfaces across portions of 
north central Illinois through around daybreak. 
Thereafter...temperatures should warm above freezing...essentially 
ending this threat. Aside from some lingering patchy drizzle this 
morning most areas will be cloudy again...but dry as temperatures 
warm into the upper 30s this afternoon. 


Model guidance continues to be in fairly good agreement through 
Tuesday...with an initial area of low pressure tracking eastward 
from the northern High Plains later today...to the upper Mississippi 
Valley by Tuesday. This still would keep all of northern 
Illinois/northwestern Indiana in the warm sector through Tuesday. It 
this system looks to be a decent rainfall producer for much of the 
area...with the best timing being Monday afternoon through late 
Monday night/early Tuesday morning. Several upper level short wave 
disturbances rotating through the larger scale upper low over the 
plains...should result in what appears to be two rounds of 
rainfall...with the first around the Monday afternoon 
timeframe...and the second Monday night. There is a small chance 
that as the precipitation onsets late Monday morning...that it could 
start as a mix of sleet and light snow...given the initial cool 
atmospheric profile. However...warm air advection will quickly warm 
things enough to result in all rain area-wide by early Monday 
afternoon. 


During the day on Tuesday it appears that we may experience a middle 
level dry punch...which if does occur would result in low clouds 
and perhaps some lingering drizzle and lower chances of much 
additional rain. Given this...I have lowered probability of precipitation a bit during the day 
on Tuesday. Temperatures across the area Monday night and Tuesday 
as we remain in the warm sector look to be mild for this time of 
year...with 40s expected. 


&& 


Long term... 
620 am CST 


Tuesday night through Saturday... 


Forecast model solutions concerning the evolution of the surface and 
upper level pattern across the central Continental U.S. From Tuesday night 
through Christmas have become more divergent over the past couple 
runs...with several solutions even now indicating the possibility 
of a much weaker surface system over the Great Lakes into 
Christmas evening due to the failure of the upper level trough 
becoming negatively tilted over the Mississippi Valley...as many 
models had been previously advertising. However...given this 
system is still 3.5 to 4 days away...I am hesitant to make any 
major changes to the going forecast for this period...as it 
appears the latest deterministic model solutions are really just 
showing US the inherent high amount of chaos in the system with 
such a rapidly changing pattern. As such...I really have no 
confidence in any of the latest 00 UTC deterministic guidance and 
would prefer to see additional runs over the next day or two show 
similar trends before beginning to making any big changes. My 
hunch is we will continue to see adjustments in the deterministic 
runs over the next couple of days as the models attempt to resolve 
the evolution of the upper level pattern over the central Continental U.S.. 


Following this system...model guidance is indicating another 
disturbance digging across the plains state by Thursday...and this 
could result in another period of precipitation across portions of 
the area by Friday. However...uncertainty with this storm is 
extremely high...given that the actual evolution of the first storm 
system will need to be ironed out first. 


Kjb 


&& 


Aviation... 


//Ord and mdw concerns...updated 14z... 


* very light snizzle/MVFR haze/br early this morning. 


* VFR ceilings likely lowering to MVFR by afternoon and continuing 
tonight. 


* South-southeast winds increasing 10-15 knots by midday...becoming southeast later 
tonight. A few gusts over 15 knots possible this afternoon. 


Ratzer/bmd 


//discussion...updated 12z... 


Southwest flow just above the surface bringing increased low level 
moisture into the area. Extensive MVFR/IFR and LIFR ceilings to the 
west and southwest...though lower ceilings more patchy across northern 
Illinois/in terminals. Weak middle-level disturbance passing early this am 
producing some very light --sn/--dz with some MVFR visible in haze/br 
but should be of relatively little impact. Otherwise...immediate 
upstream surface observation mainly VFR ceilings in 3000-4000 feet range. MVFR 
ceilings in 2000-2500 feet range across Missouri and western Illinois then 
expected to move in during the late morning/midday hours. Low 
pressure over the northern plains tonight will back winds a 
bit...with model trends supporting improvement to VFR at some 
point...though confidence lowers with extensive upstream lower 
clouds. 


South winds near 10 knots expected to increase into 10-15 knots range by 
midday...with some sporadic gusts above 15 knots possible this 
afternoon though not frequent. Winds back more southeast later 
tonight into Monday morning...increasing after sunrise. 


Ratzer 


//Ord and mdw confidence...updated 14z... 


* medium in light precipitation and ceiling trends. 


* Medium-high in winds. 


Ratzer/bmd 


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


Monday night...rain. MVFR/IFR likely. S-southeast winds. 


Tuesday...chance of rain and MVFR/IFR especially early. S-SW winds. 


Wednesday...chance of snow...possibly mixed with rain early. 
MVFR/IFR likely. Northwest winds becoming west. 


Thursday...dry. MVFR ceilings possible early. West winds becoming SW. 


Friday...chance of rain or snow. MVFR possible. S winds becoming west. 


Saturday...dry. Mainly VFR. West winds. 


Ratzer 


&& 


Marine... 
240 am CST 


Main marine concerns continue to focus on strengthening 
south-southeast winds today through late Monday...and potential for 
gusty northwest-west winds...possibly gales...from late Wednesday 
into Thursday. 


Surface high pressure ridge moved east of the lake on Saturday 
allowing winds to become southerly. The surface pressure gradient 
will slowly tighten across the upper Midwest and western lakes today 
as an area of low pressure moves southeast from the Lee of the 
Canadian rockies...with south-southeast winds increasing into the 
25-30 knots range from later this afternoon into Monday as the low 
approaches from the northern plains. The is expected to occlude and 
being to fill late Monday night...allowing the gradient to weaken 
and winds to diminish early Tuesday. The remnant surface trough will 
cross the lake late Tuesday night or early Wednesday...with light 
winds shifting to the west-northwest. 


Forecast model solutions for the surface pattern from Wednesday 
afternoon through Thursday have become more divergent over the past 
few runs...with quite a spread in the location track and depth of a 
second surface low which is expected to develop somewhere across the 
Ohio or Tennessee River valleys. Overall...guidance indicating a 
weaker low during this period...though models are obviously 
struggling with development of digging southern stream jet streak 
and the resulting upper trough and downstream surface low 
development. With such divergent solutions have avoided making large 
swings in the forecast...and have held on to the general scenario of 
previous forecast...though with slightly weaker wind field during 
the late Wednesday-Thursday period. Adjustments will undoubtedly be 
required as suite of models develop better convergence/agreement in 
their solutions. 


Ratzer 


&& 


Lot watches/warnings/advisories... 
Illinois...none. 
In...none. 
Lm...Small Craft Advisory...lmz740...10 PM Sunday to 3 am Tuesday. 


&& 


$$ 


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