Dekalb, Illinois Weather Conditions

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Current Conditions

  • 65°
  • Clear
  • Wind: South 9 mph
  • Humidity: 90%
  • Visibility: 7.0 miles
  • Dew Point: 62°
  • Pressure: 29.87 in. +

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Next 12 Hours

10  am
1  pm
4  pm
7  pm
10  pm
Chance of a Thunderstorm
Chance of T-storms
Chance of a Thunderstorm
Chance of T-storms
Thunderstorm
T-storms
Thunderstorm
T-storms
Thunderstorm
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68°
73°
72°
66°
63°
Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Thursday
  • Thunderstorm
  • High: 73 °
  • Low: 54 °
  • T-Storms
  • Friday
  • Chance of Rain
  • High: 59 °
  • Low: 34 °
  • Chance of Rain
  • Saturday
  • Chance of Rain
  • High: 48 °
  • Low: 37 °
  • Chance of Rain
  • Sunday
  • Chance of Rain
  • High: 54 °
  • Low: 37 °
  • Chance of Rain
  • Monday
  • Chance of Rain
  • High: 55 °
  • Low: 34 °
  • Chance of Rain

Forecast for Dekalb, Illinois

Updated: 10:00 AM CDT on October 02, 2014

  • Thursday

    Overcast with a chance of a thunderstorm and a chance of rain, then thunderstorms in the afternoon. High of 73F. Winds from the South at 5 to 10 mph. Chance of rain 70%.

  • Thursday Night

    Overcast with thunderstorms and rain showers, then a chance of a thunderstorm and rain showers after midnight. Fog overnight. Low of 54F. Winds from the SSW at 10 to 15 mph. Chance of rain 100% with rainfall amounts near 1.1 in. possible.

  • Friday

    Overcast with a chance of rain. High of 59F. Windy. Winds from the WNW at 15 to 25 mph with gusts to 35 mph. Chance of rain 30%.

  • Friday Night

    Mostly cloudy with a chance of rain. Low of 34F. Breezy. Winds from the West at 10 to 20 mph. Chance of rain 20%.

  • Saturday

    Overcast with a chance of rain. High of 48F. Breezy. Winds from the West at 15 to 20 mph. Chance of rain 20%.

  • Saturday Night

    Partly cloudy. Low of 37F. Winds from the WSW at 5 to 10 mph.

  • Sunday

    Mostly cloudy in the morning, then overcast with a chance of rain. High of 54F. Winds from the SSW at 5 to 10 mph. Chance of rain 20%.

  • Sunday Night

    Partly cloudy in the evening, then overcast with a chance of rain. Fog overnight. Low of 37F. Winds from the South at 5 to 10 mph shifting to the WSW after midnight. Chance of rain 20%.

  • Monday

    Partly cloudy in the morning, then overcast with a chance of rain. High of 55F. Winds from the SW at 5 to 15 mph. Chance of rain 40%.

  • Monday Night

    Partly cloudy. Fog overnight. Low of 34F. Winds from the WSW at 5 to 10 mph.

  • Tuesday

    Clear. High of 61F. Winds from the WSW at 10 to 15 mph.

  • Tuesday Night

    Clear. Low of 43F. Winds from the WSW at 5 to 10 mph.

  • Wednesday

    Partly cloudy. High of 68F. Winds less than 5 mph.

  • Wednesday Night

    Clear. Fog overnight. Low of 34F. Winds from the East at 5 to 10 mph.

  • Thursday

    Mostly cloudy with a chance of a thunderstorm. Fog early. High of 64F. Winds from the SSE at 5 to 15 mph. Chance of rain 50%.

  • Thursday Night

    Overcast with a chance of a thunderstorm. Fog overnight. Low of 48F. Winds from the WSW at 5 to 15 mph shifting to the NW after midnight. Chance of rain 50% with rainfall amounts near 0.3 in. possible.

  • Friday

    Partly cloudy. High of 59F. Winds less than 5 mph.

  • Friday Night

    Partly cloudy. Low of 45F. Winds less than 5 mph.

  • Saturday

    Mostly cloudy with a chance of rain. High of 55F. Winds less than 5 mph. Chance of rain 40%.

  • Saturday Night

    Partly cloudy with a chance of rain. Fog overnight. Low of 41F. Winds less than 5 mph. Chance of rain 40%.

  • Sunday

    Clear. High of 54F. Winds less than 5 mph.

  • Sunday Night

    Clear. Fog overnight. Low of 41F. Winds less than 5 mph.

Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: South DeKalb, DeKalb, IL

Updated: 9:26 AM CDT

Temperature: 66.6 °F Dew Point: 64 °F Humidity: 93% Wind: Calm Pressure: 29.82 in Hourly Precipitation: 0.00 in Graphs

Location: Rob's Horsepower Haven, DeKalb, IL

Updated: 9:24 AM CDT

Temperature: 66.7 °F Dew Point: 64 °F Humidity: 91% Wind: Calm Pressure: 29.83 in Hourly Precipitation: 0.00 in Graphs

Location: DeKalb, IL

Updated: 9:21 AM CDT

Temperature: 66.8 °F Dew Point: 65 °F Humidity: 93% Wind: South at 7.0 mph Pressure: 29.81 in Hourly Precipitation: - Graphs

Location: Sycamore, IL

Updated: 9:26 AM CDT

Temperature: 66.6 °F Dew Point: 64 °F Humidity: 91% Wind: SE at 3.0 mph Pressure: 29.86 in Hourly Precipitation: 0.00 in Graphs

Location: MesoWest MALTA1 IL US UPR, Malta, IL

Updated: 8:20 AM CDT

Temperature: 64 °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: 8:56 AM CDT

Temperature: 67 °F Dew Point: 66 °F Humidity: 98% Wind: SSE at 9 mph Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Heron Creek, Sycamore, IL

Updated: 9:26 AM CDT

Temperature: 67.3 °F Dew Point: 64 °F Humidity: 89% Wind: Calm Pressure: 29.87 in Hourly Precipitation: 0.00 in Graphs

Location: OG Heron Creek, Sycamore, IL

Updated: 9:26 AM CDT

Temperature: 67.6 °F Dew Point: 64 °F Humidity: 89% Wind: South at 2.9 mph Pressure: 29.83 in Hourly Precipitation: 0.00 in Graphs

Location: The Rockin' N, Waterman, IL

Updated: 9:26 AM CDT

Temperature: 76.3 °F Dew Point: - Humidity: - Wind: North at - Pressure: 29.81 in Hourly Precipitation: - Graphs

Location: Out On the Farm, Clare, IL

Updated: 9:23 AM CDT

Temperature: 67.7 °F Dew Point: 65 °F Humidity: 90% Wind: SSE at 3.0 mph Pressure: 29.83 in Hourly Precipitation: 0.00 in Graphs

Location: Ellen Oaks Subdivision, Genoa, IL

Updated: 9:26 AM CDT

Temperature: 67.1 °F Dew Point: 64 °F Humidity: 91% Wind: Calm Pressure: 29.84 in Hourly Precipitation: 0.00 in Graphs

Location: MesoWest ELBRN1 IL US UPR, Elburn, IL

Updated: 8:20 AM CDT

Temperature: 67 °F Dew Point: - Humidity: - Wind: Calm Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Genoa Road, Genoa, IL

Updated: 9:21 AM CDT

Temperature: 67.2 °F Dew Point: 65 °F Humidity: 92% Wind: SSE at 1.0 mph Pressure: 29.84 in Hourly Precipitation: 0.00 in Graphs

Location: Columbine Square, Elburn, IL

Updated: 9:22 AM CDT

Temperature: 68.2 °F Dew Point: 65 °F Humidity: 90% Wind: Calm Pressure: 29.79 in Hourly Precipitation: 0.00 in Graphs

Location: Prairie Highlands, Elburn, IL

Updated: 9:25 AM CDT

Temperature: 68.4 °F Dew Point: 66 °F Humidity: 92% Wind: Calm Pressure: 29.84 in Hourly Precipitation: 0.00 in Graphs

Location: Cheval-De-Selle, Elburn, IL

Updated: 9:12 AM CDT

Temperature: 65.8 °F Dew Point: 62 °F Humidity: 88% Wind: ESE at 2.7 mph Pressure: 29.78 in Hourly Precipitation: - Graphs

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

Updated: 8:56 AM CDT

Temperature: 66 °F Dew Point: 64 °F Humidity: 96% Wind: North at 4 mph Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Hampshire, IL, Hampshire, IL

Updated: 9:26 AM CDT

Temperature: 67.5 °F Dew Point: 64 °F Humidity: 89% Wind: South at 2.0 mph Pressure: 29.86 in Hourly Precipitation: 0.00 in Graphs

Location: K9GPC, Rochelle, IL

Updated: 9:26 AM CDT

Temperature: 66.1 °F Dew Point: 29 °F Humidity: 25% Wind: SSE at 5.4 mph Pressure: 29.09 in Hourly Precipitation: 0.00 in Graphs

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

Updated: 9:26 AM CDT

Temperature: 67.4 °F Dew Point: 66 °F Humidity: 94% Wind: South at 1.0 mph Pressure: 29.85 in Hourly Precipitation: 0.00 in Graphs

Location: OakGrove, Hampshire, IL

Updated: 9:13 AM CDT

Temperature: 68.9 °F Dew Point: 66 °F Humidity: 90% Wind: NNW at 1.7 mph Pressure: 29.74 in Hourly Precipitation: - Graphs

Location: Geneva, IL

Updated: 9:25 AM CDT

Temperature: 68.8 °F Dew Point: 64 °F Humidity: 86% Wind: ENE at 6.0 mph Pressure: 29.80 in Hourly Precipitation: 0.00 in Graphs

Location: Windswept Acres, Marengo, IL

Updated: 9:24 AM CDT

Temperature: 67.9 °F Dew Point: 66 °F Humidity: 92% Wind: SSE at 2.0 mph Pressure: 29.81 in Hourly Precipitation: 0.00 in Graphs

Location: Mill Creek, Geneva, IL

Updated: 9:19 AM CDT

Temperature: 68.3 °F Dew Point: 65 °F Humidity: 88% Wind: SSW at 4.0 mph Pressure: 29.80 in Hourly Precipitation: 0.00 in Graphs

Location: Mill Creek (NE), Geneva, IL

Updated: 9:26 AM CDT

Temperature: 68.7 °F Dew Point: 65 °F Humidity: 89% Wind: Calm Pressure: 29.84 in Hourly Precipitation: 0.00 in Graphs

Location: Paw Paw Il, Paw Paw, IL

Updated: 6:34 AM CDT

Temperature: 63.5 °F Dew Point: 62 °F Humidity: 96% Wind: Calm Pressure: 29.83 in Hourly Precipitation: 0.00 in Graphs

Location: WB9NJJ, Rochelle, IL

Updated: 9:26 AM CDT

Temperature: 69.8 °F Dew Point: 54 °F Humidity: 57% Wind: SSE at 1.6 mph Pressure: 29.56 in Hourly Precipitation: 0.00 in Graphs

Location: Thornwood, South Elgin, IL

Updated: 9:18 AM CDT

Temperature: 69.4 °F Dew Point: 66 °F Humidity: 89% Wind: WSW at 1.7 mph Pressure: 29.73 in Hourly Precipitation: - Graphs

Location: Plano, Plano, IL

Updated: 9:24 AM CDT

Temperature: 68.8 °F Dew Point: 66 °F Humidity: 89% Wind: Calm Pressure: 29.82 in Hourly Precipitation: 0.00 in Graphs

Location: Creek Side, Elgin, IL

Updated: 9:26 AM CDT

Temperature: 69.8 °F Dew Point: 64 °F Humidity: 82% Wind: SW at 1.3 mph Pressure: 28.96 in Hourly Precipitation: 0.00 in Graphs

Location: Waterford Oaks, North Aurora, IL

Updated: 9:26 AM CDT

Temperature: 69.8 °F Dew Point: 66 °F Humidity: 87% Wind: SSE at 5.0 mph Pressure: 29.84 in Hourly Precipitation: 0.00 in Graphs

Location: West Batavia, Batavia, IL

Updated: 9:16 AM CDT

Temperature: 68.4 °F Dew Point: 66 °F Humidity: 92% Wind: Calm Pressure: 29.81 in Hourly Precipitation: - Graphs

Location: Dover Ridge, Geneva, IL

Updated: 9:26 AM CDT

Temperature: 67.6 °F Dew Point: 65 °F Humidity: 90% Wind: SSE at 4.0 mph Pressure: 29.83 in Hourly Precipitation: 0.00 in Graphs

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

Updated: 9:19 AM CDT

Temperature: 67.6 °F Dew Point: 66 °F Humidity: 93% Wind: SE at 5.4 mph Pressure: 29.87 in Hourly Precipitation: 0.00 in Graphs

Location: Gilberts, IL, Gilberts, IL

Updated: 9:26 AM CDT

Temperature: 69.1 °F Dew Point: 64 °F Humidity: 85% Wind: North at 5.4 mph Pressure: 30.06 in Hourly Precipitation: 0.00 in Graphs

Location: Belvidere, Belvidere, IL

Updated: 9:22 AM CDT

Temperature: 69.1 °F Dew Point: 63 °F Humidity: 82% Wind: SW at 4.2 mph Pressure: 29.61 in Hourly Precipitation: - Graphs

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

Updated: 8:56 AM CDT

Temperature: 65 °F Dew Point: 63 °F Humidity: 92% Wind: SE at 1 mph Pressure: - Hourly Precipitation: 0.00 in Graphs

Location: Hunt Club, St. Charles, IL

Updated: 9:26 AM CDT

Temperature: 71.1 °F Dew Point: 67 °F Humidity: 86% Wind: Calm Pressure: 29.47 in Hourly Precipitation: 0.43 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 
847 am CDT Thursday Oct 2 2014 


Discussion... 
317 am CDT 


Rainfall and the potential for severe thunderstorms will be the main 
focus of this complex forecast period...with unseasonably cold air 
spreading in behind a strong cold front for the weekend. Water vapor 
imagery shows a massive upper trough over most of central and 
western North America with numerous waves embedded within the flow 
triggering areas of thunderstorms. Several of these waves are lined 
up from Texas/OK to eastern Wisconsin. At the surface...loosely 
organized low pressure is over Oklahoma with a warm front extending 
eastward from it across central Missouri and south-central Illinois. 
Warm/moist ascent is driving clusters of showers and thunderstorms 
across much of northern Missouri and central Illinois in conjunction 
with at least one of the above mentioned upper waves. 


Today and tonight...the upper wave aiding the shower/thunder 
development over the local area will lift off to the northeast this 
morning with current bands of showers and embedded thunder will exit to 
the northeast by middle morning or so. Some spotty showers/thunder may 
linger through early afternoon but there is not much support for 
large scale precipitation development through midday or even early 
afternoon...with current convection also helping to limit the 
incoming moisture flux. The surface low will begin to lift northeast 
and become marginally better organized through the afternoon as the 
main upper trough axis currently pushing toward western Kansas/OK/TX 
advances eastward. It does appear that one or several middle/upper 
waves will lift northeastward ahead of the main trough with at least 
one currently producing new convection across Oklahoma. This may 
result in an increase in convection locally from middle to late 
afternoon...especially across the western County Warning Area. Another potential 
source for convection will be the northward advancing warm frontal 
boundary which is expected to pass this afternoon and be north of the 
area by this evening. Confidence in timing/coverage details from 
about middle morning through middle afternoon is limited but will continue 
with the idea that there will be a minimum of activity during this 
time...though there may be some activity around. The surface low 
remains elongated and tracks northward along an inverted trough axis 
from northern Missouri to central Wisconsin by evening. The main 
upper trough axis will continue east as well helping to focus new 
convective development along the cold front trailing the low. This 
will lead to steadily increasing coverage of showers/storms across 
the western County Warning Area late in the afternoon with the bulk of the activity 
crossing the area this evening and tonight as the low deepens over 
Northern Lake Michigan and the upper trough axis approaches. An 
organized line of storms is expected to develop but the main 
question is how far north in the area it may extend. 


Heavy rainfall is a concern with precipitable water values of 
1.6-1.7 inches. Much of the area should see around an inch of rain 
with higher values near 2 inches possible if a line of particularly 
well organized convection does cross the area ahead of a more 
widespread area of less intense showers and storms. Severe potential 
will be a challenge with it conditional on the extent of the 
activity across the area today. Better instability would likely 
need to be advected in with the passage of the warm front. Deep 
layer shear will be strong as will the overall large scale forcing 
so even weak instability could produce severe weather...with 
guidance showing around 1000 j/kg of cape developing by late day 
which would be plenty to increase the severe threat. Damaging 
straight line winds will be the primary threat but a well developed 
squall line could spawn a few short lived tornadoes provided strong 
low level instability develops and there is sufficient low level 
turning. Unfortunately there are still too many uncertain variables 
to have good confidence in the threat for severe weather. 


Friday and Saturday...the surface low will be moving into central 
Ontario Friday morning with the cold front exiting the eastern County Warning Area. 
The exit of rain to the east may lag the front thanks to the upper 
trough axis still crossing the area. Another push of energy will be 
racing southeast across the plains Friday night spawning 
amplification of another upper trough axis which will cross the area 
Friday afternoon. This will likely bring another round of showers 
with it. Yet another waves races down the back side of the now very 
amplified longwave trough helping it to close off over Wisconsin 
Friday night which then leads to another embedded trough axis 
pivoting across the area Saturday...leading to additional low 
chances for showers during the morning/midday. The bigger story 
however will be the push of cold air brought in behind the cold 
front Friday. 850 mb temperatures will crash to about -2c by Friday evening. 
Highs Friday will likely occur early with temperatures falling into the 
upper 40s/lower 50s by evening with gusty west-northwest winds. Lows 
will fall into the upper 30s with frost development unlikely thanks 
to winds and clouds as well as some showers. Highs Saturday will 
only reach the lower 50s and some areas of the northwest may be held 
into the upper 40s. Lows Saturday night will should fall into the 
middle to upper 30s as a weak ridge axis arrives by Sunday morning. 
Winds may stay strong enough and cloud cover extensive enough to 
preclude widespread frost development. Middle level temperatures warm later 
Sunday but clouds and precipitation may temper warming so am expecting 
highs in the middle to upper 50s with 60 possible far south. 


Sunday through Wednesday...the expansive upper trough and associated 
cyclonic flow will remain in place through Tuesday before it starts 
to transition northeast and much lower amplitude flow builds in. 
This will set the stage for the passage of embedded shortwaves and 
therefore periodic shower chances with Monday looking to be a period 
of higher chances for precipitation. Middle levels will gradually warm though 
some cooling and warming will be modulated by the passage of the 
waves but overall surface temperatures will be on a slow upward trend into 
middle week...with upper 60s/lower 70s possible again by Wednesday. 


Mdb 


&& 


Aviation... 


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


* south southeast winds increasing through the day. 


* Increasing chances for showers/thunderstorms late this afternoon 
into the evening...with showers likely persisting overnight. 


* MVFR and IFR likely tonight into Friday morning...LIFR possible 
late tonight. 


* Wind shift to the west northwest with frontal passage early Friday 
morning...with increasing speeds through the end of the forecast 
period. 


Rodriguez/kb 


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


Bulk of most activity remaining outside of the terminal areas this 
morning...but with some isolated light showers moving overhead. 
Expect current showers/thunderstorms to the south to remain to the 
south as this precipitation drifts to the east this morning. With the 
departure of the showers this morning expect relatively dry 
conditions for most of today...outside of a stray shower or two. 
An isolated area of MVFR ceilings have developed across northeast 
Illinois this morning...while a more solid area of low clouds is 
situated over the eastern Iowa and far western Illinois area. The 
isolated area should dissipate over the next couple of 
hours...while the low clouds to the west remaining in this 
location for most of today. The only terminal which will likely 
observe an extended period of MVFR ceilings today will be rfd. 
Activity will likely increase very late this afternoon into the 
evening with the arrival of better large scale support for showers 
and thunderstorms. Still some uncertainty with exact timing and 
duration but at this time...a later start time does appear likely 
and have reflected this in the tafs. Thunderstorms will likely 
remain overhead for a portion of the evening but with instability 
diminishing overnight...feel that a trend towards more showers 
will occur overnight and then continue into Friday morning. The 
arrival of the better large scale support will be accompanied with 
the arrival of a surface trough from the west. This will mark the 
arrival of already present IFR ceilings...with these ceiling 
likely continuing through Friday morning. There is the potential 
for LIFR as well...but confidence is low with this possibility at 
this time. Frontal passage should quickly move across the terminals Friday 
morning...with winds quickly shifting to the west and observing a 
continued increasing trend. 


Rodriguez 


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


* medium high confidence with wind speed/duration. 


* Medium high confidence of showers/thunderstorms...low medium 
confidence of timing. 


* Medium high confidence of MVFR/IFR tonight...low medium 
confidence of LIFR. 


* High confidence of wind shift and speeds with frontal passage Friday 
morning...medium confidence of exact timing. 


Rodriguez/kb 


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


Friday night...chance of rain showers. 


Saturday...chance of rain showers. 


Sunday...slight chance of rain showers. 


Monday...chance of rain showers. 


Tuesday...VFR. 


Wednesday...VFR. 


Rodriguez 


&& 


Marine... 
441 am CDT 


Surface ridge of high pressure spans the Atlantic coast and low 
pressure is over the Southern Plains this morning...with south to 
southeast winds currently being observed across the lake. The 
surface pattern has tightened this morning and has resulted in 
some slight increase in speeds...mainly across the south half of 
the lake where 15 to 25 knots winds are being observed. These current 
speeds will likely diminish this morning...with south winds of 10 
to 20 knots being observed for the rest of the day. The low pressure 
over the Southern Plains will lift northeast to the upper 
Mississippi Valley today...and then continue northeast to the 
central Great Lakes tonight into early Friday morning while also 
strengthening. This will result in a varying wind direction as 
well as an increase in speeds through Friday. Although winds will 
be increasing through this period...it appears that speeds will 
really ramp up late Friday afternoon into the early evening. West 
gales do appear to be a definite possibility Friday night into 
early Saturday morning over the southern half of the lake...and so 
issued a gale watch. The nearshore waters will be on the fringe of 
the strongest winds but with the Indiana nearshore waters possibly 
observing these gales as well...did go ahead and include a portion 
of the Indiana nearshore zones. As the low continues north through 
Ontario to Hudson Bay Saturday and Saturday night...west winds to 
30 knots will likely continue before diminishing on Sunday. 


Rodriguez 


&& 


Lot watches/warnings/advisories... 
Illinois...none. 
In...none. 
Lm...gale watch...lmz080-lmz567-lmz669-lmz671-lmz673-lmz675-lmz744- 
lmz745-lmz777-lmz779-lmz868-lmz870-lmz872-lmz874-lmz876- 
lmz878...4 PM Friday to 9 am Saturday. 


&& 


$$ 


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