Irrigation Runtime Data Tables

Data for calculations used in this site are shown below. 

Runtime Calculation

Minutes= Weekly ETo (in)  X Shade or Full Sun X Kc / Application Rate (in/hr) /DU/Starts Per Day / Watering Days *60

Warm Season Crop Factors

Month Kc
1 0.55
2 0.54
3 0.76
4 0.72
5 0.79
6 0.68
7 0.71
8 0.71
9 0.62
10 0.54
11 0.58
12 0.55

Cool Season Crop Factors

Month Kc
1 0.61
2 0.64
3 0.75
4 1.04
5 0.95
6 0.88
7 0.94
8 0.86
9 0.74
10 0.75
11 0.69
12 0.6

Crop Factors are from UC Center for Landscape and Urban Horticulture

ETo

Zone January February March April May June July August September October November December
1 0.93 1.40 2.48 3.30 4.03 4.50 4.65 4.03 3.30 2.48 1.20 0.62
2 1.24 1.68 3.10 3.90 4.65 5.10 4.96 4.65 3.90 2.79 1.80 1.24
3 1.86 2.24 3.72 4.80 5.27 5.70 5.58 5.27 4.20 3.41 2.40 1.86
4 1.86 2.24 3.41 4.50 5.27 5.70 5.89 5.58 4.50 3.41 2.40 1.86
5 0.93 1.68 2.79 4.20 5.58 6.30 6.51 5.89 4.50 3.10 1.50 0.93
6 1.86 2.24 3.41 4.80 5.58 6.30 6.51 6.20 4.80 3.72 2.40 1.86
7 0.62 1.40 2.48 3.90 5.27 6.30 7.44 6.51 4.80 2.79 1.20 0.62
8 1.24 1.68 3.41 4.80 6.20 6.90 7.44 6.51 5.10 3.41 1.80 0.93
9 2.17 2.80 4.03 5.10 5.86 6.60 7.44 6.82 5.70 4.03 2.70 1.86
10 0.93 1.68 3.10 4.50 5.89 7.20 8.06 7.13 5.10 3.10 1.50 0.93
11 1.55 2.24 3.10 4.50 5.89 7.20 8.06 7.44 5.70 3.72 2.10 1.55
12 1.24 1.96 3.41 5.10 6.82 7.80 8.06 7.13 5.40 3.72 1.80 0.93
13 1.24 1.96 3.10 4.80 6.51 7.80 8.99 7.75 5.70 3.72 1.80 0.93
14 1.55 2.24 3.72 5.10 6.82 7.80 8.68 7.75 5.70 4.03 2.10 1.55
15 1.24 2.24 3.72 5.70 7.44 8.10 8.68 7.75 5.70 4.03 2.10 1.24
16 1.55 2.52 4.03 5.70 7.75 8.70 9.30 8.37 6.30 4.34 2.40 1.55
17 1.86 2.80 4.65 6.00 8.06 9.00 9.92 8.68 6.60 4.34 2.70 1.86
18 2.48 3.36 5.27 6.90 8.68 9.60 9.61 8.68 6.90 4.96 3.00 2.17

ETo data from CIMIS Spatial data

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Tools on this site are intended for education purposes only and are not intended for commercial use.   For more information contact Michael Spiess at California State University, Chico.