Tag: Chicago

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First Snow in Illinois

Traces of snow were reported in Chicago and Rockford on October 4. A few years ago I did a post on the earliest and median dates for the first measurable snowfall of the season. Measurable means at least 0.1 inches or more.  Snow flurries or traces of snow do not count since they have not been tracked closely in the historical weather records.

No real surprises for anyone who has experienced winter in Illinois. The earliest dates of measurable snow are in the late October, early November time frame. And the median dates range from late November in northern Illinois to the second half of December in southern Illinois. Even so, the dates can vary considerably between nearby sites since many of the early season snows are sporadic and not very widespread.

firstsnow-earliest-stn-Illinois

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When Is Fall? Astronomical, Meteorological, Climatological?

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The Quad – University of Illinois in fall color.

No doubt today (September 22) will be announced as the “first day of fall” because of the fall or autumnal equinox. However, that concept refers to the date when we get equal amounts of daylight and dark.  I don’t think it was ever intended that this astronomical event would be the start of fall. In fact, this equinox would be the start of spring in the southern hemisphere. So to be fair to everyone we should call it the September equinox and leave fall out of it.  😉

Climatologists and meteorologists prefer to use calendar months to define the four seasons in the US. For example, fall would start September 1 and end on November 30. Not only is this more convenient, because you can use monthly data, but it lines up better with the typical or average temperature pattern for Illinois. Unfortunately, the meteorologists would describe this three-month period as “meteorological fall”. However, I would argue it is “climatological fall” since we are looking at long-term average to determine the season.

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Chicago Gets Soaked Again

Heavy rains fell across the Chicago metropolitan area again today (August 22, 2014). Here is the map of rainfall amounts from our volunteer CoCoRaHS network. You will get a slightly larger and more clear image if you click on the map below. Many sites in the orange have received the average August rainfall in just 1 day. The largest total so far is from an observer in Bloomingdale in DuPage County with 5.45 inches.

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Click to enlarge.

Here are the reports for the morning of August 22, 2014, ranked from high to low. Most observers report between 7 and 8 am.

Station ID Station Name Total Precip (inches)
 IL-DP-72 Bloomingdale 0.9 NNE 5.45
 IL-CK-12 Bridgeview 1.3 NNW 4.86
 IL-GY-2 Dwight 4.1 NNW 4.82
 IL-LE-18 Sublette 0.1 NNE 4.78
 IL-CK-88 Countryside 0.8 ENE 4.69
 IL-CK-211 Oak Lawn 1.6 WNW 4.68
 IL-LS-36 Marseilles 2.8 NW 4.67
 IL-CK-152 Chicago Ridge 0.2 WSW 4.51
 IL-DP-77 Roselle 1.1 W 4.46
 IL-CK-149 Oak Lawn 0.5 SSW 4.41
 IL-CK-154 Worth 0.1 E 4.29
 IL-GY-19 South Wilmington 0.3 WNW 4.15
 IL-DP-109 Elmhurst 0.8 ESE 4.10
 IL-LS-25 Marseilles 5.6 WNW 4.10
 IL-DP-14 Westmont 1.2 SSE 4.05
 IL-KK-23 Bonfield 4.0 WSW 3.92
 IL-CK-148 Oak Lawn 1.9 SE 3.73
 IL-KN-11 St Charles 1.1 SW 3.70
 IL-LV-14 Odell 4.4 SE 3.70
 IL-CK-75 Elk Grove Village 2.2 WSW 3.69
 IL-CK-98 La Grange Park 0.7 SSW 3.64
 IL-CK-187 North Riverside 0.4 W 3.61
 IL-CK-145 Oak Park 1.5 S 3.59
 IL-DP-117 Elmhurst 2.0 SE 3.57
 IL-DP-38 Elmhurst 0.4 SW 3.55
 IL-CK-63 Elk Grove Village 0.6 ESE 3.52
 IL-KN-50 Elburn 2.7 NNE 3.48
 IL-CK-131 Schaumburg 2.0 E 3.45
 IL-DP-100 Bartlett 1.1 SE 3.35
 IL-LS-47 Earlville 7.6 SSE 3.35
 IL-KN-30 Elburn 0.4 NW 3.32
 IL-LS-50 Seneca 1.2 NNE 3.30
 IL-CK-82 Burnham-Hegewisch 1.6 NNW 3.19
 IL-LS-45 Streator 1.3 WSW 3.19
 IL-KN-63 Geneva 1.7 WSW 3.15
 IL-DP-85 Villa Park 1.0 NW 3.13
 IL-CK-61 Oak Park 1.0 SW 3.11
 IL-WF-19 Washburn 5.2 W 3.10
 IL-DP-29 Glen Ellyn 1.6 SSE 3.02
 IL-LS-51 Seneca 1.1 NNE 3.00
 IL-LV-17 Emington 2.2 SSE 3.00
 IL-LV-12 Streator 1.4 S 2.99
 IL-KN-62 Batavia 1.3 WNW 2.97
 IL-KN-58 Lily Lake 2.1 E 2.95
 IL-CK-202 River Forest 0.9 SSE 2.93
 IL-GY-9 Mazon 0.5 ENE 2.88
 IL-CK-240 Chicago 2.7 WNW 2.87
 IL-DP-79 Burr Ridge 1.9 SW 2.87
 IL-LS-17 Ottawa 1.6 N 2.82
 IL-CK-129 Schaumburg 2.7 WSW 2.81
 IL-KN-8 Geneva 3.3 WSW 2.81
 IL-LS-1 Ottawa 1.3 NW 2.78
 IL-DP-18 Downers Grove 2.1 SE 2.66
 IL-DP-40 Lombard 1.0 NNW 2.62
 IL-DP-98 Downers Grove 0.9 S 2.60
 IL-CK-192 Park Ridge 0.7 WNW 2.57
 IL-GY-12 Braceville 0.5 SSE 2.54
 IL-DP-63 Bartlett 1.0 SSE 2.51
 IL-KN-5 Batavia 0.7 WSW 2.44
 IL-CK-153 Alsip 0.2 E 2.42
 IL-CK-238 Elmwood Park 0.7 NNW 2.42
 IL-LS-49 North Utica 6.3 N 2.35
 IL-KN-78 Geneva 1.3 SSW 2.34
 IL-KN-104 Geneva 3.9 WSW 2.33
 IL-LE-14 Amboy 0.5 ESE 2.33
 IL-KN-79 Geneva 1.6 WSW 2.23
 IL-DP-49 Naperville 2.5 ESE 2.22
 IL-CK-180 Park Ridge 0.5 SSW 2.21
 IL-DP-32 Lisle 1.3 SE 2.16
 IL-CK-178 Rolling Meadows 0.9 ESE 2.15
 IL-DP-122 Clarendon Hills 0.5 NW 2.14
 IL-LS-39 Ottawa 0.5 NNW 2.14
 IL-KN-67 St. Charles 6.0 NW 2.13
 IL-KN-33 North Aurora 1.5 NE 2.12
 IL-KN-64 St. Charles 0.1 E 2.12
 IL-DK-21 De Kalb 0.6 SE 2.09
 IL-DP-118 Darien 0.4 SSE 2.09
 IL-DP-83 Lombard 1.2 NNW 2.05
 IL-CK-74 Oak Park 1.3 NNE 2.04
 IL-MCH-49 Cary 0.3 NE 2.04
 IL-DP-96 Lombard 1.0 WSW 2.02
 IL-LS-27 Oglesby 0.6 ESE 1.94
 IL-WF-12 Germantown Hills 1.3 NW 1.93
 IL-CK-121 Palatine 1.3 E 1.92
 IL-LS-34 La Salle 0.1 W 1.90
 IL-LV-7 Chatsworth 0.4 ESE 1.85
 IL-DK-10 Malta 0.4 SSE 1.84
 IL-CK-81 Arlington Heights 1.8 NNW 1.83
 IL-DP-42 Carol Stream 0.3 SSE 1.83
 IL-DP-69 Glen Ellyn 1.0 NE 1.81
 IL-DP-16 Aurora 3.6 SE 1.80
 IL-CK-107 Evanston 1.4 N 1.79
 IL-LS-2 Oglesby 0.4 N 1.79
 IL-CK-14 Chicago 5.5 ESE 1.78
 IL-CK-243 Elmwood Park 0.7 ESE 1.77
 IL-LS-12 Peru 0.6 SW 1.76
 IL-CK-32 Chicago 6.4 NNE 1.75
 IL-CK-175 Winnetka 1.2 S 1.75
 IL-WL-118 Elwood 4.6 NE 1.72
 IL-CK-235 Park Ridge 1.1 ENE 1.70
 IL-DP-101 Aurora 3.8 SE 1.66
 IL-PR-9 Dunlap 2.6 S 1.57
 IL-CK-106 Hoffman Estates 4.6 W 1.56
 IL-LS-46 Mendota 2.4 SE 1.56
 IL-KN-9 Elgin 1.0 S 1.54
 IL-KN-95 Elgin 2.5 W 1.53
 IL-IR-10 Buckley 0.2 SSE 1.52
 IL-CK-168 Ravenswood Manor 0.1 ESE 1.49
 IL-WL-119 Homer Glen 1.6 NW 1.47
 IL-DP-27 Naperville 2.1 ESE 1.45
 IL-WL-46 Peotone 0.4 ENE 1.45
 IL-KN-2 Elgin 2.3 WNW 1.39
 IL-WL-67 Channahon 2.5 SSE 1.38
 IL-KD-23 Montgomery 1.7 SSE 1.37
 IL-LV-10 Pontiac 0.7 ESE 1.37
 IL-WL-61 Channahon 0.8 NNE 1.37
 IL-WL-71 Plainfield 1.1 SW 1.37
 IL-CK-50 Palos Park 1.3 SW 1.35
 IL-KN-51 Sugar Grove 1.4 ENE 1.32
 IL-WL-25 Crete 2.6 E 1.32
 IL-WL-41 Peotone 0.5 ENE 1.32
 IL-LV-6 Pontiac 1.0 SE 1.31
 IL-MCH-43 Algonquin 0.7 N 1.31
 IL-KD-34 Plainfield 4.8 SW 1.30
 IL-WL-84 Beecher 3.4 ENE 1.30
 IL-WL-99 Manhattan 1.9 SE 1.29
 IL-DP-102 Bolingbrook 2.7 NE 1.28
 IL-WL-20 Manhattan 4.7 ENE 1.28
 IL-WL-79 Peotone 0.5 SE 1.27
 IL-CK-215 Glenview 0.9 SW 1.26
 IL-WL-93 New Lenox 4.2 SE 1.26
 IL-GY-20 Morris 2.5 SSE 1.25
 IL-WL-121 Monee 4.9 W 1.25
 IL-WN-19 Rockton 1.0 ESE 1.24
 IL-WL-36 Homer Glen 3.9 WNW 1.22
 IL-CK-206 Park Forest 1.0 SW 1.21
 IL-KN-107 South Elgin 0.9 WSW 1.20
 IL-SP-7 Davis 0.5 N 1.17
 IL-LK-39 Riverwoods 0.4 ENE 1.14
 IL-WL-104 Plainfield 2.7 SE 1.14
 IL-LK-25 Lincolnshire 1.3 WSW 1.13
 IL-KD-46 Oswego 1.0 SW 1.10
 IL-SP-18 Freeport 0.9 ESE 1.10
 IL-WL-16 Homer Glen 0.8 ENE 1.07
 IL-WL-51 Plainfield 2.4 SSE 1.06
 IL-FD-9 Gibson 3.0 WNW 1.05
 IL-WL-80 Lockport 1.3 SE 1.05
 IL-WL-100 Joliet 2.9 WNW 1.05
 IL-KD-5 Montgomery 0.8 SSE 1.04
 IL-WL-120 Joliet 1.2 W 1.04
 IL-KX-11 Galesburg 8.8 S 1.03
 IL-WL-82 Orland Park 4.6 WNW 1.03
 IL-HY-6 New Windsor 2.0 N 1.02
 IL-LK-16 Buffalo Grove 1.5 N 1.02
 IL-WL-64 Joliet 2.3 WNW 1.02
 IL-GY-10 Minooka 0.3 NE 1.01
 IL-CK-146 Glenwood 1.5 ESE 1.00
 IL-KN-82 Batavia 0.8 S 1.00
 IL-LS-7 Sheridan 3.4 SSE 1.00
 IL-LK-69 Highwood 0.9 S 0.99
 IL-CK-53 Glencoe 0.1 NW 0.98
 IL-CK-94 Lincolnwood 1.8 E 0.98
 IL-MCH-66 Harvard 2.8 SSE 0.97
 IL-FL-9 London Mills 1.4 SE 0.95
 IL-WL-111 New Lenox 1.0 NE 0.95
 IL-WF-14 El Paso 5.2 NNW 0.95
 IL-KX-9 Knoxville 0.7 NW 0.93
 IL-MCH-13 Bull Valley 2.5 WNW 0.92
 IL-KK-25 Bonfield 4.2 NNE 0.91
 IL-WL-50 Lockport 3.3 ESE 0.91
 IL-KD-24 Oswego 5.0 SSE 0.90
 IL-KN-91 Hampshire 0.7 W 0.89
 IL-DP-57 Aurora 3.5 NE 0.88
 IL-GY-4 Coal City 0.4 N 0.87
 IL-GY-16 Morris 6.4 ESE 0.87
 IL-WL-73 Wilmington 2.6 SE 0.86
 IL-MCH-61 Woodstock 1.5 WSW 0.84
 IL-WL-97 New Lenox 3.3 E 0.84
 IL-LK-11 Lincolnshire 0.9 N 0.83
 IL-GY-21 Coal City 2.8 N 0.82
 IL-WL-103 Joliet 1.8 NNE 0.80
 IL-CK-42 Mount Prospect 3.0 NE 0.79
 IL-LK-53 Lakemoor 1.5 SE 0.78
 IL-WL-108 Plainfield 4.1 NW 0.78
 IL-LK-15 Bannockburn 0.5 ESE 0.77
 IL-TZ-14 Morton 1.0 SSE 0.77
 IL-KK-28 Chebanse 0.4 NNE 0.76
 IL-WL-123 Bolingbrook 1.4 W 0.76
 IL-CK-232 Lincolnwood 3.2 E 0.75
 IL-GY-1 Carbon Hill 3.1 N 0.75
 IL-LV-4 Chenoa 3.9 NNW 0.75
 IL-TZ-1 Morton 1.0 S 0.74
 IL-WN-30 Pecatonica 2.3 S 0.74
 IL-KN-86 Elgin 7.5 WSW 0.72
 IL-LK-9 Lake Villa 1.1 SSW 0.72
 IL-LE-8 Ashton 0.4 SSW 0.71
 IL-LK-74 Mundelein 1.6 WNW 0.70
 IL-WL-72 New Lenox 2.9 ENE 0.69
 IL-LK-22 Lake Forest 2.1 NNE 0.68
 IL-MCD-5 Macomb 0.6 WNW 0.68
 IL-LK-70 Fox Lake 2.4 SE 0.67
 IL-WL-105 Plainfield 2.9 NNW 0.65
 IL-DP-75 Naperville 1.1 NW 0.64
 IL-MCH-59 Harvard 0.3 E 0.64
 IL-SP-6 Freeport 2.0 NW 0.64
 IL-WN-2 Roscoe 1.6 ESE 0.64
 IL-LK-54 Mundelein 0.5 NNE 0.62
 IL-MR-4 Aledo 0.4 NE 0.62
 IL-LK-86 Mundelein 1.8 NW 0.60
 IL-LK-13 Lake Bluff 1.3 W 0.59
 IL-MCL-2 Arrowsmith 1.7 NNE 0.59
 IL-MR-6 Aledo 0.4 NE 0.59
 IL-BU-8 Tiskilwa 2.1 N 0.58
 IL-DK-17 De Kalb 1.8 NNE 0.58
 IL-BN-14 Capron 0.1 N 0.57
 IL-KK-26 Kankakee 3.2 SE 0.55
 IL-CK-197 Orland Hills 0.6 SE 0.53
 IL-LK-42 Gurnee 1.6 W 0.53
 IL-LK-83 Antioch 3.4 WSW 0.53
 IL-WD-5 Morrison 3.2 E 0.53
 IL-LK-29 Lake Bluff 1.4 W 0.51
 IL-SP-8 Winslow 4.3 ESE 0.51
 IL-WD-14 Sterling 4.9 WSW 0.51
 IL-WL-63 New Lenox 1.8 SE 0.51
 IL-MCL-9 Danvers 1.7 WNW 0.50
 IL-SP-14 Freeport 1.7 ESE 0.50
 IL-DK-5 Cortland 0.3 SSW 0.49
 IL-MCH-33 Woodstock 3.8 SW 0.48
 IL-MCH-52 Woodstock 0.8 SSW 0.47
 IL-LK-3 Beach Park 1.4 W 0.45
 IL-LK-19 Waukegan 2.2 N 0.45
 IL-TZ-10 Tremont 3.6 E 0.45
 IL-LK-72 Wadsworth 1.4 SSE 0.44
 IL-MCL-23 Normal 1.9 ESE 0.44
 IL-IR-14 Watseka 6.9 WNW 0.43
 IL-OG-4 Byron 3.2 N 0.43
 IL-WN-14 Rockford 3.3 NE 0.43
 IL-BU-5 Princeton 1.1 SE 0.42
 IL-BU-9 La Moille 0.2 NNE 0.42
 IL-CK-64 Homewood 0.1 ESE 0.42
 IL-LK-8 Gurnee 2.5 NE 0.42
 IL-LK-84 Waukegan 1.7 E 0.40
 IL-LE-10 Dixon 3.0 NNW 0.39
 IL-WF-18 El Paso 6.2 SW 0.39
 IL-CK-170 Flossmoor 0.5 SW 0.38
 IL-HY-1 Orion 4.1 NW 0.38
 IL-MCL-18 Bloomington 3.2 NE 0.36
 IL-LE-5 Sterling 4.3 NE 0.35
 IL-MCL-17 Bloomington 2.7 NE 0.35
 IL-CR-11 Milledgeville 0.4 ESE 0.34
 IL-DP-78 Naperville 2.4 SE 0.34
 IL-MCL-32 Danvers 0.34
 IL-WN-8 Rockford 0.7 NW 0.34
 IL-KD-12 Yorkville 1.1 W 0.33
 IL-WL-113 New Lenox 2.1 SE 0.33
 IL-KK-34 Bradley 1.1 SW 0.32
 IL-WD-8 Coleta 1.4 SSW 0.32
 IL-IR-2 Ashkum 5.6 E 0.31
 IL-RI-10 Moline 1.1 N 0.31
 IL-CP-81 Dewey 1.6 NNW 0.30
 IL-LK-23 Winthrop Harbor 0.2 SSE 0.30
 IL-SP-17 Pearl City 0.4 SW 0.30
 IL-KK-22 Bourbonnais 1.5 NNE 0.29
 IL-KD-25 Yorkville 1.8 SSE 0.27
 IL-LK-27 Winthrop Harbor 0.7 SSW 0.27
 IL-LE-17 Dixon 1.5 SW 0.27
 IL-RI-3 Moline 0.9 N 0.27
 IL-RI-13 Moline 0.7 NNE 0.26
 IL-CR-12 Mount Carroll 6.8 NNW 0.25
 IL-HY-4 Atkinson 2.6 NNE 0.25
 IL-HY-8 Geneseo 2.0 NW 0.25
 IL-LG-32 Lincoln 2.7 NNE 0.22
 IL-OG-12 Davis Junction 1.1 SW 0.22
 IL-KD-7 Plano 0.4 NNE 0.20
 IL-WN-26 Rockford 1.5 ENE 0.20
 IL-KK-35 Bourbonnais 2.9 E 0.19
 IL-MCD-7 Colchester 3.5 NE 0.19
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Sharp Contrast Between Chicago and Portland Temperatures This Summer

As impressive as this cool summer has been in Illinois, the experience here and across the Midwest stands in stark contrast to the West Coast. Here is the temperature contrast from the last full month – July (map below – click to enlarge). While the Corn Belt was 3 to 6 degrees below average in July, the West Coast and parts of the Rockies have been running 3 to 6 degrees, or more, above average.

The contrast between Chicago and Portland (OR), two of my favorite cities, show how different things have been. For July, the average high in Chicago was 79.8 degrees and the average low was 60.9 degrees. The average monthly temperature of 70.4 degrees meant that Chicago was 3.6 degrees below average.

On the other hand, the average high for July in Portland was 83.8 degrees and the average low was 59.8 degrees. As a result, their average monthly temperature of 71.8 degrees meant that Portland was 2.6 degrees above average.

Furthermore, while Chicago barely reached 90 degrees on one day in July, Portland reached or exceeded 90 degrees 7 days in July, including a reading of 99 on July 1.

The long-term average temperature for July in Chicago is 74 degrees and in Portland is 69 degrees.

It is no surprise that the NWS forecasts indicate that the heat will remain in the West for the next two weeks. However, it looks like Illinois has a good chance of seeing above-average temperatures for a change in the August 16-24 period.

july-us