Boy do we need rain: May weather summary

Temperature and precipitation data listed below were collected at the Monmouth weather station located a little more than 4 miles from the Northwestern Illinois Agricultural Research and Demonstration Center (NWIARDC), while soil temperature and moisture probes are located at the NWIARDC.

Air temperature. The monthly average high and low temperatures hovered near average during May (Table).

APRIL 2014 WEATHER

Soil Temperature

Air Temp

4" (Bare)

4" (Sod)

(°F)

Growing Degree Days

-------------------(°F)---------------

Monthly average high

73

Monthly total: 390

72

63

Monthly average low

51

57

58

Observed high (date)

88 (22)

26 (8)

85 (24)

75 (31)

Observed low (date)

37 (24)

0 (2)

42 (18)

49 (2,3,4)

Precipitation and soil moisture

May precipitation was 3.84 inches, 0.66 inches below the 30-year average and 6.71 inches less than in May 2013 (Table). We need the rain that is forecasted tomorrow as soils are abnormally dry according to the National Drought Monitor (Figure).

The Illinois State Water Survey (ISWS) measures soil moisture (as water fraction by volume) 2, 4, 8 and 22 inches below the soil surface at the NWIARDC. Soil moisture values are specific to individual soil types. In order to make sense of current soil moisture measurements, we can compare measurements to the values for field capacity (how much water the soil is capable of holding before draining) and wilting point (the soil moisture level at which plants are no longer capable of extracting water)of the NWIARDC's silt loam soil. Soil moisture levels are approaching the wilting point at both the 2 and 4 inch depths (Figure). This does not bode well for newly seeded stands of corn and soybean and is likely why stand establishment and growth has been so uneven in Western Illinois.

2014 PRECIPITATION (in inches)

Since January 1

Month

Monthly Total

Monthly departure from average

Total accumulation

Total departure

January

1.19

-0.47

1.19

-0.47

February

3.33

+1.46

4.52

+0.99

March

2.49

-0.26

7.01

+0.73

April

4.29

+0.37

11.30

+0.11

May

3.84

-0.66

15.14

-0.55