Illinois on List Twice for Billion-Dollar Weather Disasters of 2013

According to the National Climatic Data Center, Illinois was on the list twice for billion-dollar weather disasters in 2013. In both cases, some damages occurred elsewhere but Illinois took the brunt of the losses. These numbers are based on reports from government agencies, media reports, and insurance industry estimates.

2013-top-9-billion-dollar-events

The first was the flooding in the Chicago area in April 2013. I had posts on this event here, here, and here. This event produced an estimated $1 billion in damages and led to 4 deaths. They described it as:

A slow-moving storm system created rainfall totals of 5 to 10 inches across northern and central Illinois including the Chicago metro. This resulted in damage to many homes and businesses. There was also severe weather damage from wind and hail across Indiana and Missouri.

The second was the November 17, 2013, tornado outbreak that caused an estimated $1 billion in damages and led to 8 deaths. I wrote about it herehere, here, here, and here. They described it as:

Late-season outbreak of tornadoes and severe weather over the Ohio Valley (IL, IN, MO, OH, KY, MI) with 70 confirmed tornadoes. Most severe impacts occurred across Illinois and Indiana.

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Wetter Averages and Extremes for Chicago Area

The recent rains and associated flooding in the Chicago area are reflecting the long-term pattern of wetter conditions in the region. Here are a few samples of that pattern.

First of all, northeast Illinois (Cook and several surrounding counties – see map below) has experienced a shift in precipitation over the last 120 years. This plot shows the amounts for each year as green dots, and an 11-year running average showing longer periods of dry conditions (brown) and wet conditions (green). There is a pretty remarkable shift from a drier climate between 1895 and 1965 with lots of brown, towards a wetter climate from 1966 to present where green dominates.

If you compare the average annual precipitation between the two periods, you get 32.9 inches for the earlier period and 36.8 inches for the later period. That is a 3.9 inch increase, or about 12 percent.

If you look at the 10 wettest years in the record, 8 out of the 10 came after the shift in 1965. The two exceptions were 1902 at #1 and 1954 at #10.

Rank Year Precipitation
1 1902 48.02
2 1972 46.68
3 2008 45.95
4 1990 45.66
5 2009 45.40
6 1993 44.34
7 2011 43.12
8 1982 42.77
9 1970 42.76
10 1954 41.54

Of course, we have still experienced drought conditions in this later wet period, as noted in 2005 and 2012. However, the wetter years far outnumber the dry years since 1965. BTW, this pattern is not unique. I have seen this across the state.

Here is the same plot for northeast Illinois for just the month of August. The green shading comes in a little later, showing generally wetter conditions since the 1980s. What is startling is the number of very wet Augusts in the last 50 years. The two wettest were 1987 with 10.04 inches and 2007 with 10.88 inches, which is more than double the long-term average.

As this plots show, the issue is not just a shift towards a wetter period over time but a shift towards wetter extremes as well.

As of August 27, 2014, the northeast region is at 5.4 inches, 1.83 inches above average.

Here is the region used in this discussion (aka Climate Division 2). Climate divisions are regions of roughly similar climate. The advantages of a regional average are no missing data and increased statistical confidence in the resulting values. You can read more about them here.

northeast

Posted in Climate Monitoring, Heavy Rains | Tagged , | 1 Comment

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.

august22

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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Weather Outlook for Fall and Winter in Illinois

The NOAA Climate Prediction Center released their monthly outlook for September and 3-month outlooks for September and beyond. At this time, they are not expecting a repeat of last winter for Illinois.

According to them, the chance of El Niño has decreased to about 65% during the Northern Hemisphere fall and early winter. If it does show up, it is expected to a moderate to weak event. As a result, the impacts on the US and the Midwest will likely be modest at best.

September and FALL

For both September and this fall, there is an equal chance (EC) of above, below, near-average temperature and precipitation (4-panel figure below) for Illinois. The north-central US is not expected to have below-average temperatures, like it has experienced this summer. This may give crops in those areas a better chance of reaching maturity this fall.

It does look like temperatures are expected to stay above-average on the West and East Coast, as well as Alaska. Wetter-than-average conditions are expected to prevail in the southwest US, and expand into the Plains and parts of Iowa and Missouri later in the fall.

 

page2

 

 

WINTER (December-February)

For Illinois, the current forecast is for equal chances of above, below, and near-average temperatures. Or to put it another way, they see no sign of a repeat of last winter. And they are expecting below-average precipitation in Illinois and across the Great Lakes region. It is still early in the year to lock in on this forecast so I would not cancel orders for snow blowers or salt deliveries just yet.

off04_tempoff04_prcp

Posted in Climate Monitoring, El Nino, Seasonal Outlooks | Tagged , , , , | 1 Comment

Dryness Across Northern and Central Illinois

After a wet start to the 2014 growing season, we have seen a significant drop in rainfall across parts of northern and central Illinois in the last few weeks. Here is the 30-day rainfall as a percent of average. Areas in the orange are 25 to 75 percent of average while the areas in red are less than 25 percent of average. There are reports of soil moisture running low in some areas. On the other hand, southern Illinois has received above-average rainfall in the last 30 days.

IL-prcp-mpe-030-pct-20140818

Besides the switch from too wet to too dry in northern and central Illinois, and too much rain in southern Illinois, the other issue is that temperatures have been running about 4 degrees below average for the past 30 days. We are getting some heat this week. However, the longer-term forecasts indicate a return to cooler temperatures and more rain after this week through September 1.

If you look at the last 90 days the heavier rains in June and early July masks the recent dryness (map below). In fact, at the 90 day time scale rainfall in Illinois is generally at or above long-term average (1981-2010), as denoted by the grays and greens. This is one of the challenges of drought monitoring – sorting out short-term dryness versus long-term wetness or vice versa.

IL-prcp-mpe-090-pct-20140818

 

Posted in Agriculture, Climate Monitoring, Cold, Heavy Rains | Tagged , , , , | Leave a comment

Cool Maps of the Cool July

I will admit it – ever since I was a kid I have been fascinated/obsessed with maps. It is probably why I ended up in a career in climatology since we use maps all the time.

Here are maps from the National Climatic Data Center showing how cool July was across the Midwest. The regions are called “climate divisions” and there are nine of them in Illinois. The ones in the darkest blue had their coolest July on record, with records going back to 1895. Click on the map for a larger version which shows the numbers more clearly.

You can read more about what happened in the US in July.

July Temperature Ranking. Click to enlarge. Source National Climatic Data Center.

July Temperature Ranking. Click to enlarge. Source National Climatic Data Center.

And here are the temperature departures from the 1981-2010 average.

July Temperature Departures. Click to enlarge. Source National Climatic Data Center.

July Temperature Departures. Click to enlarge. Source National Climatic Data Center.

Here is the US map for July, showing that while the Midwest was cool, the western US was experiencing record warmth.

july-us

Click to enlarge. Source National Climatic Data Center

This temperature pattern across the United States is the result of a ridge of high pressure over the western US and a trough of low pressure over the central US throughout most of July.

july-upper

 

 

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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

Posted in Chicago, Climate Monitoring, Heat | Tagged , , | 1 Comment