Wet June and Wettest Year-to-Date in Illinois

Based on preliminary numbers, the statewide average precipitation for June 2013 in Illinois was 5.19 inches. That was 0.99 inches above the 1981-2010 average. It was more than double the June 2012 total of 1.80 inches.
In the first map below, the two wettest areas in Illinois were in northern Illinois and an area just to the south of Interstate 70. The area in northern Illinois was part of a larger area of heavy amounts in northeastern Iowa and southern Wisconsin. The area in southern Illinois extended into southern Indiana and Kentucky. Both regions had rainfall totals in excess of 8 inches and even 10 or more inches in the red and purple areas.
By contrast, much of the rest of the state was close to average precipitation for June with 3 to 6 inches very common (shades of green on the map). The few areas in blue (representing less than 3 inches) in western and north central Illinois are not alarming yet because they followed a wet spring. In fact, much of the Midwest experienced a wet June, including the Ohio River Valley which experienced drier conditions early in the month.
The second map zooms in on Illinois and shows the departures from average for June. The wet areas in northern and south-central Illinois stand out with rainfall totals 3 to 5 inches above average. Areas in central and southwestern Illinois were below average.

30-day precipitation through the morning of June 30 for the Midwest.
30-day precipitation through the morning of June 30 for the Midwest. Click to enlarge.

June Precipitation Departure from Average.
June Precipitation Departure from Average.

 
The year to date (January-June) statewide precipitation for Illinois was 28.74. That was 8.91 inches above the 1981-2010 average and the wettest January-June on record. The statewide records go back to 1895. It is more than double the 12.67 inches accumulate in January-June of 2012 during the height of the drought.
The statewide average temperature was 71.5 degrees, which was 0.3 degrees below the 1981-2010 average.

Wettest Locations In Illinois in June

Location and June precipitation total in inches, ranked high to low. List cut off for sites with less than 5 inches to keep the list somewhat short.
                    FLORA 12.63
     BELLEVILLE SCOTT AFB 12.34
     BELLEVILLE SIU RSRCH 10.97
              CARY 0.3 NE 10.72
         BROOKPORT DAM 52 10.37
        CENTREVILLE 1.9 E 10.33
               STEWARD 3S 9.78
     MCHENRY STRATTON L&D 9.69
              TROY 1.4 SE 9.68
              CARY 1.9 NE 9.62
           YORKVILLE 3 SW 9.5
       BELLEVILLE 4.5 WNW 9.35
              HIDALGO 3SW 9.3
          CLAY CITY 6 SSE 9.16
             PALESTINE 2W 9.02
               GREENVILLE 9.01
      WHITE HEATH 3.7 NNE 8.99
             CAPRON 0.1 N 8.79
      LAWRENCEVILLE RIVER 8.76
           AVISTON 0.4 NW 8.73
                 OLNEY 2S 8.7
        BELLEVILLE 2.2 SE 8.67
              ROSCOE 2 SE 8.66
          ROCKFORD 3.3 NE 8.54
                BELVIDERE 8.5
           CHAMPAIGN 9 SW 8.49
                 KINMUNDY 8.46
         WOODSTOCK 0.7 SW 8.44
         BELKNAP 11.1 ESE 8.42
        MASCOUTAH 0.5 WSW 8.39
     EDWARDSVILLE 0.9 WSW 8.32
     HAWTHORN WOODS 0.6 N 8.3
                    SALEM 8.27
     GRANITE CITY 1.4 ENE 8.26
             ATWOOD 0.4 N 8.24
         SHERIDAN 0.1 SSW 8.23
                 ROBINSON 8.21
      WONDER LAKE 0.8 WNW 8.17
                  HARVARD 8.16
               ALBERS 1 W 8.16
                 HIGHLAND 8.11
          ROCKFORD 0.7 NW 8.09
           PALATINE 1.3 E 8.07
       ORANGEVILLE 2.8 NW 8.04
          ALGONQUIN 0.7 N 7.98
                    CASEY 7.87
       PARK RIDGE 0.7 WNW 7.87
             CARLYLE RSVR 7.82
       HARRISBURG 4.6 NNE 7.77
                ELIZABETH 7.76
 ROCKFORD GTR ROCKFORD AP 7.72
           SHABBONA 5 NNE 7.72
               CHARLESTON 7.64
         OKAWVILLE 2.3 SW 7.58
                  MATTOON 7.52
         CHARLESTON 1.0 S 7.51
             FREEPORT WWP 7.5
             SPRING GROVE 7.5
         EDWARDSVILLE 2 W 7.43
          MARSEILLES LOCK 7.42
                  DE KALB 7.38
            SMITHLAND L&D 7.36
           STOCKTON 3 NNE 7.35
            DE KALB 1.4 W 7.35
             DIXON 1.5 SW 7.33
                 VANDALIA 7.33
         PECATONICA 2.3 S 7.32
 ARLINGTON HEIGHTS 1.2 SW 7.29
        MANSFIELD 3.0 WSW 7.29
          WINSLOW 4.3 ESE 7.29
                  MARENGO 7.28
              SHABBONA 3S 7.23
            DUNLAP 2.6 NE 7.21
         CHARLESTON 0.9 S 7.2
           FARMER CITY 3W 7.19
                  TUSCOLA 7.18
           WOODSTOCK 5 NW 7.17
                  WINDSOR 7.09
      BUFFALO GROVE 1.5 N 7.07
              DAVIS 0.5 N 7.04
          BARRINGTON 3 SW 6.99
ARLINGTON HEIGHTS 1.8 NNW 6.98
          ROCKTON 1.0 ESE 6.97
     LINCOLNSHIRE 1.3 WSW 6.96
 ST. FRANCISVILLE 2.3 NNW 6.96
            EARLVILLE 3 S 6.96
           MARSHALL 4.6 W 6.89
                  PAW PAW 6.85
          CHAMPAIGN 3.6 W 6.83
                CENTRALIA 6.82
            WATSON 0.3 NE 6.81
           PEORIA 3.4 WNW 6.8
         ROCKFORD 1.5 ENE 6.79
             EFFINGHAM SE 6.74
       NEW MILLFORD 3.3 W 6.74
        CHAMPAIGN 2.3 NNW 6.7
                     IUKA 6.69
      LAWRENCEVILLE 1.4 W 6.68
      BULL VALLEY 2.5 WNW 6.67
       MONTGOMERY 1.7 SSE 6.65
                   GALENA 6.63
             MT OLIVE 1 E 6.63
        CHAMPAIGN 2.5 WNW 6.59
        CHAMPAIGN 0.3 ESE 6.55
        CHAMPAIGN 3.5 SSE 6.54
               TRIMBLE 1E 6.52
         WINNETKA 0.8 ESE 6.52
         SHERIDAN 3.4 SSE 6.51
           ASHTON 0.4 SSW 6.51
                    NEOGA 6.5
          FREEPORT 2.0 NW 6.5
                  ST ANNE 6.47
             MENDOTA 2 SE 6.45
             GALENA 5.7 E 6.43
              CAIRO RIVER 6.37
          YORKVILLE 1.1 W 6.33
          TUSCOLA 1.4 NNE 6.25
                CAIRO 3 N 6.24
    CHICAGO OHARE INTL AP 6.23
       RIVERWOODS 0.4 ENE 6.23
                NEOGA 4NW 6.22
             RED BUD 5 SE 6.22
            LISBON 4.4 NE 6.22
            MATTOON 1.3 W 6.21
                   URBANA 6.2
              BYRON 3.2 N 6.2
       MONTGOMERY 0.8 SSE 6.2
          LAKEMOOR 1.5 SE 6.19
 MOLINE QUAD CITY INTL AP 6.14
                    AMBOY 6.06
          MUNDELEIN 4 WSW 6.05
                   AURORA 6.04
       GRAND CHAIN DAM 53 6.03
                   HAVANA 6.03
      BANNOCKBURN 0.5 ESE 5.99
                   FISHER 5.98
            DIXON 3.0 NNW 5.95
 CHICAGO BOTANICAL GARDEN 5.94
          CHICAGO 5.5 ESE 5.93
       LINCOLNSHIRE 0.9 N 5.92
           ASHLEY 1.4 NNE 5.89
       PLAINFIELD 2.4 SSE 5.88
      KANKAKEE METRO WWTP 5.88
              SAVOY 0.9 N 5.86
               MT CARROLL 5.83
 CHANNAHON DRESDEN ISLAND 5.81
        LINCOLNWOOD 1.8 E 5.8
         EVANSTON 1.2 SSE 5.78
         PETERSBURG 7.5 W 5.73
                   MORRIS 5.71
               NEW ATHENS 5.71
        CHANNAHON 0.8 NNE 5.7
                  ROANOKE 5.69
      VILLA GROVE 0.6 ESE 5.69
        MARSEILLES 2.8 NW 5.68
        MOUNT OLIVE 0.4 S 5.65
       MARSEILLES 5.6 WNW 5.64
           GLENCOE 0.1 NW 5.63
           MORRIS 4.8 NNW 5.62
            NASHVILLE 1 E 5.6
          PEOTONE 0.4 ENE 5.6
       BROADLANDS 0.1 SSW 5.55
                  BUFFALO 5.54
        PLAINFIELD 1.1 SW 5.53
             GIRARD 1.2 W 5.49
     SHAWNEETOWN OLD TOWN 5.47
             SIDNEY 0.9 N 5.46
  HARWOOD HEIGHTS 1.9 NNE 5.46
             URBANA 1.8 N 5.45
     FAIRFIELD RADIO WFIW 5.43
        PLAINFIELD 4.8 SW 5.43
              KEWANEE 1 E 5.42
           COLETA 1.4 SSW 5.42
                   HARDIN 5.41
                  CHESTER 5.41
           LE ROY 4.1 SSW 5.41
                   RIPLEY 5.4
             EMDEN 2.4 SW 5.36
       MONTICELLO 3.5 NNE 5.36
           OSWEGO 5.0 SSE 5.35
               PEORIA 5NW 5.35
          KANKAKEE 3.2 SE 5.35
            SPARLAND 6 SW 5.33
         CHADWICK 2.7 WSW 5.32
      SUGAR GROVE 1.4 ENE 5.3
                  RANTOUL 5.3
                EFFINGHAM 5.23
                  DECATUR 5.22
            AURORA 3.8 SE 5.21
             MILFORD 5 NW 5.19
            AMBOY 0.5 ESE 5.18
                 ROCHELLE 5.18
        LONDON MILLS 1 SW 5.16
           SPARTA 1.9 SSW 5.16
     KASKASKIA RIV NAV LO 5.15
             AURORA 3.4 W 5.14
          PEOTONE 0.5 ENE 5.13
         CHAMPAIGN 0.7 SW 5.12
            PHILO 1.9 ENE 5.11
          PLAINFIELD 3 NE 5.1
           MINOOKA 0.3 NE 5.06
                    CISCO 5.05
            AURORA 3.6 SE 5.05
ELK GROVE VILLAGE 0.6 ESE 5.04
        CHANNAHON 2.5 SSE 5.03
           MENDOTA 2.4 SE 5.02
           PEOTONE 0.5 SE 5.02
           JACKSONVILLE 2 5.01
               MONEE RSVR 5

Ninth Wettest June on Record for Illinois

The statewide average precipitation for June in Illinois was 6.7 inches. That’s 2.6 inches above the 1971-2000 average. Rainfall totals at individual sites were impressive. The highest rainfall total for June was from a CoCoRaHS observer near Warsaw (Henderson County) who reported 20.85 inches. NWS cooperative observers in Loami reported 14.48 inches and in Jacksonville reported 13.74 inches
The statewide average temperature for June was 72.8 degrees, 0.9 degrees above average. The warmest reported temperature for the month was 100 degrees in DuQuoin on June 4.
If it feels like we are seeing a lot of wet Junes, you are right. First is a list of the top ten wettest Junes in Illinois:

  1. 8.37 inches in 1902
  2. 7.68 inches in 1998
  3. 7.67 inches in 2010
  4. 7.31 inches in 1928
  5. 7.13 inches in 2000
  6. 6.99 inches in 1924
  7. 6.89 inches in 1993
  8. 6.80 inches in 1945
  9. 6.73 inches in 2011
  10. 6.52 inches in 1957
We also have a five-year streak of above-average precipitation for June in Illinois:
  • 2007: 4.18 inches, 0.06 inches above average
  • 2008: 5.74 inches, 1.62 inches above average
  • 2009: 5.20 inches, 1.08 inches above average
  • 2010: 7.67 inches, 3.53 inches above average
  • 2011: 6.73 inches, 2.61 inches above average
We don’t know what will happen in July. However, the last three years have ended up with wetter than average July’s, on a statewide basis.

Wet Year So Far in Illinois

The statewide precipitation for June is 6.6 inches, 2.5 inches above the 1971-2000 average (normal). That makes it the ninth wettest June on record (based on preliminary numbers as of June 28, 2011).
The statewide precipitation for the first six months of 2011 is 27.2 inches, 7.7 inches above the 1971-2000 average. That makes it the fourth wettest January-June on record. Statewide records go back to 1895.
The figure below shows the June departure from normal precipitation across the US. Cool coolers (green, blue, purple) show abnormally wet conditions. Warm colors show abnormally dry conditions. Wet conditions have prevailed from Montana, into the Dakotas, Nebraska, Iowa, northeastern Missouri, across Illinois, and much of the lower Ohio River valley. However, dry conditions are not far from Illinois borders, especially to our southwest.

June rainfall across the US (courtesy NOAA).
June departure from normal precipitation across the US (source NOAA). Click to enlarge.

The figure below shows the year-to-date departure from normal precipitation across the US. Like June, the band of above-normal precipitation extends from Montana, down the Missouri River, and up the Ohio River valleys. This area has seen abundant atmospheric moisture and a strong, persistent jet stream for much of winter and spring. Meanwhile, the Southwest and South have struggled with dry conditions. BTW, it is not unusual to have one part of the US experiencing drought while another part experiences heavy rains and flooding. It is amazing that you can go from southern Illinois with its 8 to 16 inches of above normal precipitation to Arkansas and Mississippi and find areas that are 8 to 16 inches below normal on precipitation.
Year to date precipitation departure for the US.
Year to date departure from normal precipitation across the US (source NOAA). Click to enlarge.

June Is Wet and Warm, So Far

Based on preliminary data, the average temperature for Illinois in the first half of June is 73.2 degrees, 2.9 degrees above average. The statewide average precipitation was 3.32 inches, 1.13 inches above average.
Table 1 shows the temperatures and precipitation for June by climate division, also known as crop reporting districts. Much of Illinois has been wet, but far southern Illinois has been on the dry side in the last few weeks. Not that it’s necessarily a problem since that area had exceptional rainfall totals in both April and May.
Table 2 shows the same thing, only for the year to date. Overall, Illinois temperatures in 2011 are about 1 degree below average while precipitation is 6.42 inches above average. The precipitation departures are most impressive in southern Illinois and exceed 10 inches in those areas.

Table 1. Illinois conditions for June 1-16, 2011.

Climate          <------Temperature----->   <---------Precipitation--------->
Division         Actual   Normal      Dev   Actual   Normal     Dev   Percent
-----------------------------------------------------------------------------
Northwest          69.6     68.1      1.4     3.39     2.32     1.08      147
Northeast          68.8     67.5      1.3     3.62     2.26     1.36      160
West               72.3     70.3      2.0     5.86     2.17     3.68      269
Central            71.7     70.0      1.7     3.34     2.08     1.25      160
East               72.0     69.9      2.1     3.13     2.17     0.96      144
West-southwest     74.6     71.1      3.4     4.17     2.05     2.13      204
East-southeast     75.3     71.4      3.9     2.77     2.22     0.55      125
Southwest          77.8     72.1      5.7     1.35     2.16    -0.81       63
Southeast          78.0     72.5      5.5     1.74     2.27    -0.53       77
State              73.2     70.2      2.9     3.32     2.19     1.13      152

Table 2. Illinois conditions for January 1 – June 16, 2011.

Climate          <------Temperature----->   <---------Precipitation--------->
Division         Actual   Normal      Dev   Actual   Normal     Dev   Percent
-----------------------------------------------------------------------------
Northwest          39.5     41.4     -1.8    19.64    15.32     4.32      128
Northeast          40.0     41.5     -1.5    21.44    15.58     5.87      138
West               43.1     44.7     -1.5    21.44    16.30     5.14      132
Central            42.7     44.1     -1.4    20.70    16.16     4.54      128
East               42.9     43.9     -1.0    21.98    16.30     5.68      135
West-southwest     45.4     46.5     -1.1    21.92    17.19     4.73      127
East-southeast     46.5     47.0     -0.5    26.56    18.77     7.79      142
Southwest          48.9     49.0     -0.1    30.20    19.93    10.27      152
Southeast          49.6     49.3      0.3    33.15    21.75    11.40      152
State              44.1     45.1     -1.0    23.74    17.32     6.42      137
Dev means Deviation From Normal, Percent means Percent of Normal