Pond Evaporation Calculation 1/31/20
Weather Station Data provided by Northern Colorado Water Conservancy District
See Weather Station Location Map at:
http://www.northernwater.org/WaterConservation/WeatherandETData.aspx
Notes:
Current month reflects values through "Reference Date".
Pond Evap. calculated per recent Division 1 Water Court decree language: Lower South Platte Home Page
Gross Pond = .84(Alfalfa ETr) Pond Evaporation Reports Main Menu
Net Pond = .84(Alfalfa ETr) - .7(Total Precip)
Alfalfa reference ETr computed by Standard ASCE equation from daily weather data.
Winter pond evap. is a reference for unfrozen ponds.
For Growing Degree Days:
Tmax = 86 F, Tmin = 50 F and Tbase = 50 F
Totals
Weather Station 2019 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec or Avg.
Ovid Avg. Temp F 28.11 19.93 32.8 49.25 51.38 67.24 75.05 71.43 67.37 42.68 34.54 29.93 47.48
Ref date as of 12/31/2019 Total Precip " 0.09 0.35 1.83 1.04 5.93 2.38 2.71 4.07 1.28 0.33 0.46 0.19 20.66
Site Type: Alfalfa Total Alfalfa ETr " 2.17 1.55 2.85 6.03 5.55 8.91 9.2 7.08 7.3 4.22 2.08 1.32 58.26
Total Growing Degee Days from March 1 0 0 56 246 236 501 702 662 539 207 96 26 3271
Gross Pond Evap Total " 1.82 1.3 2.39 5.07 4.66 7.48 7.73 5.95 6.13 3.54 1.75 1.11 48.93
Net Pond Evap Total " 1.76 1.06 1.11 4.34 0.51 5.82 5.83 3.1 5.24 3.31 1.43 0.98 34.49
Crook Avg. Temp F 27.67 20.26 32.98 48.93 50.15 65.45 73.92 70.7 65.95 41.79 34.08 29.65 46.79
Ref date as of 12/31/2019 Total Precip " 0.09 0.31 1.49 1.39 6.05 1.7 1.4 3.63 1.56 0.33 0.18 0.09 18.22
Site Type: Alfalfa Total Alfalfa ETr " 2.07 1.54 2.91 5.64 4.95 7.53 8.31 6.79 6.5 3.99 1.71 1.11 53.05
Total Growing Degee Days from March 1 0 0 62 236 227 470 670 646 516 204 96 19 3146
Gross Pond Evap Inch 1.74 1.29 2.44 4.74 4.16 6.33 6.98 5.7 5.46 3.35 1.44 0.93 44.56
Net Pond Evap Inch 1.68 1.08 1.4 3.76 0 5.14 6 3.16 4.37 3.12 1.31 0.87 31.89
 
Sterling Avg. Temp F 27.76 21.8 33.97 49.45 51.25 65.71 75.07 71.91 66.81 42.65 33.84 29.85 47.51
Ref date as of 12/31/2019 Total Precip " 0.14 0.25 1.4 1 3.55 1.76 0.78 2.72 1.08 0.45 0.32 0.23 13.68
Site Type: Alfalfa Total Alfalfa ETr " 1.86 1.53 3 5.6 5.3 7.99 8.71 7.36 6.38 3.99 1.63 1.09 54.44
Total Growing Degee Days from March 1 0 0 69 238 241 467 688 665 521 208 97 11 3205
Gross Pond Evap Inch 1.56 1.29 2.52 4.7 4.45 6.71 7.32 6.18 5.36 3.35 1.37 0.92 45.73
Net Pond Evap Inch 1.46 1.11 1.54 4 1.97 5.48 6.77 4.28 4.6 3.04 1.15 0.75 36.15
 
Brush Avg. Temp F 25.99 22.09 34.2 49.45 51.15 64.37 74.3 71.74 66.1 42.38 32.63 28.4 46.9
Ref date as of 12/31/2019 Total Precip " 0.39 0.53 1.97 0.44 3.58 2.96 0.46 2.03 0.64 0.59 0.61 19.56 33.76
Site Type: Alfalfa Total Alfalfa ETr " 1.67 1.58 3.12 5.95 5.44 7.51 8.75 7.55 6.37 3.85 1.08 0.84 53.71
Total Growing Degee Days from March 1 0 0 76 253 247 462 678 659 523 240 93 7 3238
Gross Pond Evap Inch 1.4 1.33 2.62 5 4.57 6.31 7.35 6.34 5.35 3.23 0.91 0.71 45.12
Net Pond Evap Inch 1.13 0.96 1.24 4.69 2.06 4.24 7.03 4.92 4.9 2.82 0.48 0 34.47
 
Fort Morgan Avg. Temp F 27.04 22.7 34.43 49.88 51.68 65.15 75.25 71.89 66.72 42.93 33.16 28.84 47.47
Ref date as of 12/31/2019 Total Precip " 0.28 0.33 2.04 0.49 3.18 1.84 0.8 3.25 1.06 0.69 0.68 0.37 15.01
Site Type: Turf Total Alfalfa ETr " 1.58 1.51 2.98 5.44 5.52 7.6 8.7 7.56 6.29 3.54 1.16 0.98 52.86
Total Growing Degee Days from March 1 0 0 73 247 246 464 698 666 531 227 97 5 3254
Gross Pond Evap Inch 1.33 1.27 2.5 4.57 4.64 6.38 7.31 6.35 5.28 2.97 0.97 0.82 44.39
Net Pond Evap Inch 1.13 1.04 1.08 4.23 2.41 5.1 6.75 4.08 4.54 2.49 0.5 0.56 33.91
 
Wiggins Avg. Temp F 26.09 22.51 33.88 49.51 51.15 65.27 74.75 71.82 66.53 42.66 32.54 28.05 47.06
Ref date as of 12/31/2019 Total Precip " 0.25 0.38 2.01 0.43 2.95 0.87 1.27 1.3 0.94 0.58 0.74 0.26 11.98
Site Type: Alfalfa Total Alfalfa ETr " 1.68 1.68 3.23 5.79 5.6 8.43 9.38 7.94 6.8 3.98 1.29 0.91 56.71
Total Growing Degee Days from March 1 0 0 77 246 247 468 686 655 530 230 91 4 3234
Gross Pond Evap Inch 1.41 1.41 2.71 4.86 4.7 7.08 7.88 6.67 5.71 3.34 1.08 0.76 47.61
Net Pond Evap Inch 1.24 1.15 1.31 4.56 2.64 6.47 6.99 5.76 5.05 2.94 0.57 0.58 39.26
 
Fort Collins East Avg. Temp F 30.32 25.69 33.87 48.75 49.9 64.01 72.25 71.34 64.22 42.65 34.58 28.53 47.18
Ref date as of 12/31/2019 Total Precip " 0.36 0.19 1.77 0.98 2.36 2.28 1.14 0.37 0.43 0.54 15.46 0.38 26.26
Site Type: Alfalfa Total Alfalfa ETr " 1.87 2.18 3.26 5.47 4.81 7.33 8 7.8 5.91 3.92 1.67 1.02 53.24
Total Growing Degee Days from March 1 0 0 62 215 216 445 645 626 480 202 87 10 2988
Gross Pond Evap Inch 1.57 1.83 2.74 4.59 4.04 6.16 6.72 6.55 4.96 3.29 1.4 0.86 44.71
Net Pond Evap Inch 1.32 1.7 1.5 3.91 2.39 4.56 5.92 6.29 4.66 2.91 0 0.59 35.75
 
Eaton Avg. Temp F 28.33 24.17 33.72 48.88 50.2 64.14 72.39 70.44 64.27 42.21 33.39 26.6 46.56
Ref date as of 12/31/2019 Total Precip " 0.33 0.18 2.9 1.11 2.45 7.17 0.5 1.58 0.73 0.62 1.11 0.78 19.46
Site Type: Alfalfa Total Alfalfa ETr " 1.85 2.01 3.31 5.63 5.24 7.81 8.19 7.47 5.95 4.11 1.57 0.78 53.92
Total Growing Degee Days from March 1 0 0 64 226 230 448 640 628 485 206 79 1 3007
Gross Pond Evap Inch 1.55 1.69 2.78 4.73 4.4 6.56 6.88 6.27 5 3.45 1.32 0.66 45.29
Net Pond Evap Inch 1.32 1.56 0.75 3.95 2.69 1.54 6.53 5.17 4.49 3.02 0.54 0.11 31.67
 
Johnsons Corner Avg. Temp F 29.89 26.05 34.41 48.38 49.71 63.76 72.44 71.66 65.8 43.2 34.85 30.91 47.59
Ref date as of 12/31/2019 Total Precip " 0.69 0.21 1.05 1.36 2.73 2.05 1.36 0.46 0.82 1.1 1.65 0.3 13.78
Site Type: Alfalfa Total Alfalfa ETr " 1.67 1.92 3.21 5.06 4.7 7.15 8.26 7.76 6.36 3.64 1.3 1.03 52.06
Total Growing Degee Days from March 1 0 0 55 205 199 432 655 645 502 191 77 14 2975
Gross Pond Evap Inch 1.4 1.61 2.7 4.25 3.95 6.01 6.94 6.52 5.34 3.06 1.09 0.87 43.74
Net Pond Evap Inch 0.92 1.47 1.96 3.3 2.04 4.57 5.99 6.2 4.77 2.29 0 0.66 34.17
 
Gilcrest Avg. Temp F 28.4 24.78 34.86 49.46 51.43 65.86 74.3 72.22 64.9 42.85 32.57 27.25 47.41
Ref date as of 12/31/2019 Total Precip " 0.51 0.41 1.03 1.47 1.91 2 1 1.11 1.77 15.46 1.1 0.4 28.17
Site Type: Alfalfa Total Alfalfa ETr " 1.7 1.75 3.21 5.32 5.46 8.15 9 7.85 6.02 3.66 1.25 0.81 54.18
Total Growing Degee Days from March 1 0 0 72 238 243 472 678 656 505 228 86 2 3180
Gross Pond Evap Inch 1.43 1.47 2.7 4.47 4.59 6.85 7.56 6.59 5.06 3.07 1.05 0.68 45.52
Net Pond Evap Inch 1.07 1.18 1.98 3.44 3.25 5.45 6.86 5.82 3.82 0 0.28 0.4 33.55
 
Longmont South Avg. Temp F 30.19 26.3 34.77 48.9 50.09 64.34 72.34 70.88 65.02 43.14 35.27 31.63 47.74
Ref date as of 12/31/2019 Total Precip " 1.01 0.29 1.12 1.03 2.51 2.52 2.38 0.53 0.57 1.05 1.45 0.22 14.68
Site Type: Alfalfa Total Alfalfa ETr " 1.7 1.89 3.1 4.89 4.34 6.99 7.9 7.21 5.92 3.72 1.7 1.26 50.62
Total Growing Degee Days from March 1 0 0 62 217 211 450 638 615 487 203 95 24 3002
Gross Pond Evap Inch 1.43 1.59 2.6 4.11 3.65 5.87 6.64 6.06 4.97 3.12 1.43 1.06 42.53
Net Pond Evap Inch 0.72 1.38 1.82 3.39 1.89 4.11 4.97 5.69 4.57 2.39 0.41 0.9 32.24
 
Fort Collins NW Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 12/31/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Fort Collins Central Avg. Temp F 31.38 26.51 34.67 48.93 50.31 63.86 72.68 71.6 64.66 42.15 34.86 30.1 47.64
Ref date as of 12/31/2019 Total Precip " 0.51 0.18 1.1 0.92 3.7 2.49 0.95 0.39 0.79 0.76 0.13 0.33 12.25
Site Type: Turf Total Alfalfa ETr " 1.35 1.96 3.05 4.75 4.68 6.54 7.17 6.66 5.35 3.12 1.16 0.91 46.7
Total Growing Degee Days from March 1 0 0 64 221 217 441 635 622 488 201 94 28 3011
Gross Pond Evap Inch 1.13 1.65 2.56 3.99 3.93 5.49 6.02 5.59 4.49 2.62 0.97 0.76 39.2
Net Pond Evap Inch 0.78 1.52 1.79 3.35 1.34 3.75 5.36 5.32 3.94 2.09 0.88 0.53 30.65
 
Windsor Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 7/1/2012 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Dryland Pasture Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Greeley West Avg. Temp F 29.66 25.91 35.46 50.33 51.83 66.16 75.25 73.86 67.45 43.81 34.56 29.24 48.63
Ref date as of 12/31/2019 Total Precip " 0.55 0.26 1.82 0.57 1.59 1.88 1.19 0.4 1.49 0.91 1.45 10.4 22.51
Site Type: Turf Total Alfalfa ETr " 1.81 1.95 3.33 5.42 5.3 7.41 8.19 7.4 5.8 3.38 1.04 0.84 51.87
Total Growing Degee Days from March 1 0 0 74 249 250 484 703 687 543 220 84 2 3296
Gross Pond Evap Inch 1.52 1.64 2.8 4.55 4.45 6.22 6.88 6.22 4.87 2.84 0.87 0.71 43.57
Net Pond Evap Inch 1.14 1.46 1.52 4.15 3.34 4.91 6.05 5.94 3.83 2.2 0 0 34.54
 
Loveland Avg. Temp F 30.49 27.52 36.01 49.81 51.42 65.51 74.3 73.05 66.73 43.89 35.4 31.21 48.78
Ref date as of 12/31/2019 Total Precip " 0.74 0.21 1.62 2.06 2.43 1.8 1.65 0.29 0.88 1.29 1.81 0.26 15.04
Site Type: Turf Total Alfalfa ETr " 1.65 1.96 3.13 4.72 4.69 6.63 7.59 7 5.46 3.35 1.19 1 48.37
Total Growing Degee Days from March 1 0 0 87 252 239 482 701 676 549 229 107 28 3350
Gross Pond Evap Inch 1.39 1.65 2.63 3.96 3.94 5.57 6.38 5.88 4.59 2.81 1 0.84 40.64
Net Pond Evap Inch 0.87 1.5 1.5 2.52 2.24 4.31 5.22 5.68 3.97 1.91 0 0.66 30.38
 
Berthoud Avg. Temp F 30.02 26.01 34.42 48.82 50.25 64.53 73.37 72.25 66.55 43.45 35.18 31.22 48.01
Ref date as of 12/31/2019 Total Precip " 0.68 0.16 1.19 1.28 2.65 1.95 1.79 0.58 0.74 1.09 1.64 0.33 14.08
Site Type: Turf Total Alfalfa ETr " 1.68 1.85 3.05 4.89 4.96 7.17 8.3 7.38 5.93 3.43 1.35 1.06 51.05
Total Growing Degee Days from March 1 0 0 57 222 212 450 681 666 514 195 76 9 3082
Gross Pond Evap Inch 1.41 1.55 2.56 4.11 4.17 6.02 6.97 6.2 4.98 2.88 1.13 0.89 42.87
Net Pond Evap Inch 0.94 1.44 1.73 3.21 2.31 4.66 5.72 5.79 4.46 2.12 0 0.66 33.04
 
Longmont West Avg. Temp F 30.43 27.45 35.67 49.88 51.24 65.47 74.09 73.05 66.91 43.99 35.52 31.8 48.79
Ref date as of 12/31/2019 Total Precip " 0.84 0.18 1.25 0.74 2.9 2.33 2.69 1.19 1.76 0.74 0.28 0.3 15.2
Site Type: Turf Total Alfalfa ETr " 1.56 1.85 2.99 4.71 4.79 6.79 7.53 6.77 5.37 3.07 1.11 1.07 47.61
Total Growing Degee Days from March 1 0 0 61 220 212 459 683 675 517 211 93 38 3169
Gross Pond Evap Inch 1.31 1.55 2.51 3.96 4.02 5.7 6.33 5.69 4.51 2.58 0.93 0.9 39.99
Net Pond Evap Inch 0.72 1.43 1.64 3.44 1.99 4.07 4.44 4.85 3.28 2.06 0.74 0.69 29.35
 
Fort Lupton Avg. Temp F 31.07 26.39 35.33 50.19 51.67 65.78 74.69 73.73 67.98 44.96 35.55 31 49.03
Ref date as of 12/31/2019 Total Precip " 0.7 0.61 1.27 0.39 2.22 1.58 1.1 1.93 0.89 0.9 1.04 0.37 13
Site Type: Turf Total Alfalfa ETr " 1.86 1.88 3.28 5.58 5.69 7.97 9.15 8.29 6.87 3.81 1.48 1.08 56.94
Total Growing Degee Days from March 1 0 0 64 234 240 480 701 694 554 228 97 29 3321
Gross Pond Evap Inch 1.56 1.58 2.76 4.69 4.78 6.69 7.69 6.96 5.77 3.2 1.24 0.91 47.83
Net Pond Evap Inch 1.07 1.15 1.87 4.41 3.23 5.59 6.92 5.61 5.15 2.57 0.52 0.65 38.74
 
Boulder NW Avg. Temp F 32.28 27.56 35.37 49.26 50.13 64.82 73.57 73.28 67.05 44.05 37.01 34.18 49.05
Ref date as of 12/31/2019 Total Precip " 1.55 0.41 2.14 1.49 5.01 2.05 2.11 0.38 1.05 1.37 0.44 0.17 18.17
Site Type: Turf Total Alfalfa ETr " 1.91 2.01 3.09 5.03 4.64 6.83 7.84 7.38 5.92 3.35 1.52 1.08 50.6
Total Growing Degee Days from March 1 0 0 63 223 213 451 668 664 521 194 104 49 3150
Gross Pond Evap Inch 1.6 1.69 2.6 4.23 3.9 5.74 6.59 6.2 4.97 2.81 1.28 0.91 42.52
Net Pond Evap Inch 0.52 1.4 1.1 3.18 0.39 4.3 5.11 5.93 4.24 1.86 0.97 0.79 29.79
 
Boulder East Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder Flatiron Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder SW Avg. Temp F 34.85 29.3 36.3 49.97 50.81 64.82 73.73 73.47 68.38 46.11 39.14 37.1 50.33
Ref date as of 12/31/2019 Total Precip " 1.41 0.24 0.07 0.05 0.14 2.58 1.37 0.3 0.66 0.98 0.3 0 8.1
Site Type: Turf Total Alfalfa ETr " 2.17 2.2 3.14 5.14 4.63 6.7 7.67 7.3 5.98 3.75 1.83 1.69 52.2
Total Growing Degee Days from March 1 0 0 51 199 198 439 644 639 523 198 103 45 3039
Gross Pond Evap Inch 1.82 1.85 2.64 4.32 3.89 5.63 6.44 6.13 5.02 3.15 1.54 1.42 43.85
Net Pond Evap Inch 0.84 1.68 2.59 4.28 3.79 3.82 5.48 5.92 4.56 2.46 1.33 1.42 38.17
Greeley04 Avg. Temp F 28.55 23.34 34.09 48.75 51.4 65.29 73.38 71.15 64.57 40.71 32.8 25.65 46.64
Ref date as of 12/31/2019 Total Precip " 0.14 0.08 1.46 0.77 1.21 2.05 0.43 0.46 1.63 0.18 0.14 0.31 8.86
Site Type: Fully irrigated Total Alfalfa ETr " 2.34 2.21 3.64 6.01 6.13 8.54 9.28 8.13 6.44 4.71 2.18 1.21 60.82
Total Growing Degee Days from March 1 0 0 68 228 248 469 669 639 495 195 78 0 3089
Gross Pond Evap Inch 1.97 1.86 3.06 5.05 5.15 7.17 7.8 6.83 5.41 3.96 1.83 1.02 51.11
Net Pond Evap Inch 1.87 1.8 2.04 4.51 4.3 5.74 7.49 6.51 4.27 3.83 1.73 0.8 44.89