Average May 2015 Weather Near 30-Year "Normal"

Precipitation. May precipitation at the Northwestern Illinois Agricultural Research and Demonstration Center (NWIARDC) totaled 4.76 inches - surpassing the total accumulated during the four previous months combined (Table) and totaling very close to the 30-year normal. Unlike other areas of the state and country that were deluged with several inches of rain at a time, the rain at the NWIARDC arrived on 18 of the month's 31 days (Figure).

2015 PRECIPITATION (in inches)

Since January 1

Month

Monthly Total

Monthly departure from average

Total accumulation

Total departure

January

1.32

-0.20

1.32

-0.20

February

1.28

-0.26

2.60

-0.46

March

0.83

-1.70

3.43

-2.16

April

1.21

-2.67

4.64

-4.83

May

4.76

+0.01

Temperature. The average daily high and low air temperatures remained close to the 30-year "normals" for the month of May (Figure).

May 2015 WEATHER

Soil Temperature

Air Temp

2" (Bare)

4" (Bare)

4" (Sod)

(°F)

Growing Degree Days

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

Monthly average high

74

Monthly total: 470.5

73

74

65

Monthly average low

53

58

57

61

Observed high (date)

84 (4)

24 (29)

79 (5)

80 (23)

71 (27)

Observed low (date)

32 (1)

0 (21)

47 (1,21,23)

50 (1)

Reference. Water and Atmospheric Resources Monitoring Program. Illinois Climate Network. (2015). Illinois State Water Survey, 2204 Griffith Drive, Champaign, IL 61820-7495.