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