Pond Evaporation Calculation													1/31/19
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	2018	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	or Avg.
Ovid	Avg. Temp ° F	26.12	24.25	38.74	43.06	61.94	71.81	73.83	69.99	65.24	45.86	34.64	27.65	48.59
Ref date as of 12/31/2018	Total Precip "	0.37	0.57	0.57	1.96	4.68	4.75	2.84	1.6	1.15	1.53	0.57	0.48	21.07
Site Type: Alfalfa	Total Alfalfa ETr "	1.53	1.99	4.72	5.72	7.63	9.89	9.35	7.61	6.38	4.01	2.63	1.94	63.4
Total Growing Degee Days from March 1		0	0	117	162	415	598	700	594	479	210	77	29	3381
Gross Pond Evap	Total "	1.29	1.67	3.96	4.8	6.41	8.31	7.85	6.39	5.36	3.37	2.21	1.63	53.25
Net Pond Evap	Total "	1.03	1.27	3.57	3.43	3.13	4.98	5.87	5.27	4.55	2.3	1.81	1.29	38.5
Crook	Avg. Temp ° F	28.24	25.6	40.16	44.42	61.39	71.46	74.03	69.33	63.51	45.26	34.78	27.12	48.78
Ref date as of 12/31/2018	Total Precip "	0.38	0.43	0.6	1.45	3.18	2.45	2.73	1.1	2.6	1.28	0.42	0.22	16.84
Site Type: Alfalfa	Total Alfalfa ETr "	1.54	1.91	4.54	5.2	6.24	8.52	9.12	7.44	5.84	3.72	2.73	2.02	58.82
Total Growing Degee Days from March 1		0	0	137	171	401	574	688	576	447	209	73	28	3304
Gross Pond Evap	Inch	1.29	1.6	3.81	4.37	5.24	7.16	7.66	6.25	4.91	3.12	2.29	1.7	49.4
Net Pond Evap	Inch	1.03	1.3	3.39	3.35	3.02	5.44	5.75	5.48	3.09	2.23	2	1.54	37.62
Sterling	Avg. Temp ° F	28.83	26.59	41.68	46.14	61.58	71.69	74.45	69.37	64.56	46.22	35.13	27.46	49.48
Ref date as of 12/31/2018	Total Precip "	0.38	0.54	0.29	1.18	4.35	1.23	2.46	1.05	0.4	1.03	0.27	0.13	13.31
Site Type: Alfalfa	Total Alfalfa ETr "	1.89	2.27	5.53	6.33	7.22	9.68	9.65	7.34	6.13	3.68	2.47	1.8	63.99
Total Growing Degee Days from March 1		0	0	157	195	401	572	688	578	463	222	77	29	3382
Gross Pond Evap	Inch	1.59	1.91	4.65	5.32	6.06	8.13	8.11	6.17	5.15	3.09	2.07	1.51	53.76
Net Pond Evap	Inch	1.32	1.53	4.44	4.49	3.02	7.27	6.38	5.43	4.87	2.37	1.89	1.42	44.43
Brush	Avg. Temp ° F	28.23	26.78	41.78	46.96	61.37	70.24	73.62	69.01	63.48	46.4	34.56	26.75	49.1
Ref date as of 12/31/2018	Total Precip "	0.36	0.58	0.31	0.71	4.97	1.13	1.99	0.88	0.16	1.26	0.24	0.16	12.75
Site Type: Alfalfa	Total Alfalfa ETr "	1.96	2.34	6.31	6.96	6.82	9.06	9.48	7.67	5.95	3.85	2.6	1.94	64.94
Total Growing Degee Days from March 1		0	0	174	217	406	552	673	575	454	229	84	34	3398
Gross Pond Evap	Inch	1.65	1.97	5.3	5.85	5.73	7.61	7.96	6.44	5	3.23	2.18	1.63	54.55
Net Pond Evap	Inch	1.39	1.56	5.08	5.35	2.25	6.82	6.57	5.83	4.89	2.35	2.02	1.52	45.63
Fort Morgan	Avg. Temp ° F	27.4	25.65	40.67	45.98	61.05	71.04	74.16	69.79	64.69	46.9	35.43	27.77	49.21
Ref date as of 12/31/2018	Total Precip "	0.15	0.37	0.28	0.69	4.58	3.58	3.3	0.95	0.19	1	0.14	0.03	15.26
Site Type: Turf	Total Alfalfa ETr "	1.57	2.02	5.09	5.99	6.64	8.51	8.47	7.09	5.67	3.31	2.18	1.6	58.14
Total Growing Degee Days from March 1		0	0	146	200	392	568	690	600	469	224	78	29	3396
Gross Pond Evap	Inch	1.32	1.7	4.28	5.03	5.58	7.15	7.11	5.96	4.76	2.78	1.83	1.34	48.84
Net Pond Evap	Inch	1.21	1.44	4.08	4.55	2.37	4.64	4.8	5.29	4.63	2.08	1.73	1.32	38.14
Wiggins	Avg. Temp ° F	27.14	25.94	40.81	46.49	61.19	70.77	72.86	69.74	63.49	46.41	34.56	26.92	48.86
Ref date as of 12/31/2018	Total Precip "	0.28	0.49	0.4	0.63	3.97	2.93	1.51	0.75	0.34	0.45	0.19	0.02	11.96
Site Type: Alfalfa	Total Alfalfa ETr "	1.76	2.33	5.71	6.65	7.02	9.41	9.04	8.08	5.88	3.82	2.53	1.92	64.15
Total Growing Degee Days from March 1		0	0	161	207	402	548	655	585	457	230	80	32	3357
Gross Pond Evap	Inch	1.48	1.96	4.8	5.59	5.9	7.9	7.59	6.79	4.94	3.21	2.13	1.61	53.9
Net Pond Evap	Inch	1.28	1.61	4.52	5.15	3.12	5.85	6.54	6.26	4.7	2.89	1.99	1.6	45.51
Fort Collins East	Avg. Temp ° F	30.48	27.34	41.69	46.48	59.46	69.99	71.62	68.07	62.47	46.54	36.05	29.15	49.11
Ref date as of 12/31/2018	Total Precip "	0.28	0.57	0.79	0.77	3.09	1.06	1.16	0.1	0.38	0.62	0.41	0.1	9.33
Site Type: Alfalfa	Total Alfalfa ETr "	2.22	2.46	5.5	6.38	6.46	9.59	8.39	7.45	5.99	3.59	2.7	2.19	62.92
Total Growing Degee Days from March 1		0	0	136	199	365	531	626	554	439	210	61	28	3149
Gross Pond Evap	Inch	1.86	2.07	4.62	5.36	5.43	8.06	7.05	6.26	5.03	3.02	2.27	1.84	52.87
Net Pond Evap	Inch	1.67	1.67	4.07	4.82	3.26	7.31	6.24	6.19	4.77	2.58	1.98	1.77	46.33
Eaton	Avg. Temp ° F	29.25	25.95	41.05	46.37	59.96	69.75	70.96	67.77	62.89	46.06	35.11	28.05	48.6
Ref date as of 12/31/2018	Total Precip "	0.4	0.63	0.89	0.77	3.81	1.53	1.11	0.25	0.17	0.61	0.43	0.04	10.64
Site Type: Alfalfa	Total Alfalfa ETr "	1.93	2.37	5.4	6.63	6.97	9.11	7.88	6.94	6.02	3.72	2.61	1.93	61.51
Total Growing Degee Days from March 1		0	0	142	212	379	525	622	554	453	212	60	26	3185
Gross Pond Evap	Inch	1.62	1.99	4.54	5.57	5.85	7.65	6.62	5.83	5.06	3.12	2.19	1.62	51.66
Net Pond Evap	Inch	1.34	1.55	3.91	5.03	3.19	6.58	5.84	5.65	4.94	2.7	1.89	1.59	44.21
Johnsons Corner	Avg. Temp ° F	31.79	28.12	42.29	46.95	59.55	70.06	71.69	69.03	63.91	47.23	36.35	30.33	49.78
Ref date as of 12/31/2018	Total Precip "	0.47	0.88	0.98	0.89	3.57	3.73	2.61	0.69	0.14	0.99	0.59	0.16	15.7
Site Type: Alfalfa	Total Alfalfa ETr "	2.05	2.37	5.01	5.93	6.04	8.98	7.97	7.42	6.02	3.41	2.39	2.04	59.63
Total Growing Degee Days from March 1		0	0	128	187	350	541	647	587	443	197	51	23	3154
Gross Pond Evap	Inch	1.72	1.99	4.21	4.98	5.07	7.54	6.69	6.23	5.06	2.86	2.01	1.71	50.07
Net Pond Evap	Inch	1.39	1.37	3.52	4.36	2.57	4.93	4.87	5.75	4.96	2.17	1.59	1.6	39.08
Gilcrest	Avg. Temp ° F	28.41	27.22	42.18	47.79	60.56	71.3	72.46	69.79	64.13	46.82	35.89	28.62	49.6
Ref date as of 12/31/2018	Total Precip "	0.45	0.58	0.99	1.01	2.73	4.16	3.35	0.75	1.2	0.99	0.47	0.11	16.79
Site Type: Alfalfa	Total Alfalfa ETr "	1.74	2.42	5.16	6.39	6.8	9.79	8.43	7.98	6.24	3.45	2.41	1.92	62.73
Total Growing Degee Days from March 1		0	0	153	222	383	554	659	588	461	221	72	26	3339
Gross Pond Evap	Inch	1.46	2.03	4.33	5.37	5.71	8.22	7.08	6.7	5.24	2.9	2.02	1.61	52.67
Net Pond Evap	Inch	1.15	1.63	3.64	4.66	3.8	5.31	4.74	6.18	4.4	2.21	1.7	1.54	40.96
Longmont South	Avg. Temp ° F	31.68	28.71	41.74	46.87	58.68	69.73	71.19	68.87	63.18	47.15	36.65	30.45	49.58
Ref date as of 12/31/2018	Total Precip "	0.44	0.76	1.57	1.05	4.91	2.35	2.22	1.29	0.65	1.24	0.63	0.21	17.32
Site Type: Alfalfa	Total Alfalfa ETr "	2.11	2.58	4.97	5.95	5.9	8.79	7.85	7.36	5.69	3.44	2.56	2.09	59.29
Total Growing Degee Days from March 1		0	0	130	193	342	516	618	568	442	202	67	31	3109
Gross Pond Evap	Inch	1.77	2.17	4.17	5	4.96	7.38	6.59	6.18	4.78	2.89	2.15	1.76	49.8
Net Pond Evap	Inch	1.46	1.64	3.08	4.26	1.52	5.74	5.04	5.28	4.32	2.02	1.71	1.61	37.68
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	31.18	28.58	42.32	47.32	59.72	69.83	71.88	69.01	63.01	46.05	36.22	29.32	49.54
Ref date as of 12/31/2018	Total Precip "	0.25	0.36	0.67	0.76	4.57	1.22	1.89	0.38	0.36	0.77	0.52	0.05	11.8
Site Type: Turf	Total Alfalfa ETr "	1.79	2.23	4.59	5.53	5.96	7.99	7.26	6.41	5.16	2.76	2.03	1.57	53.28
Total Growing Degee Days from March 1		0	0	134	201	366	519	623	567	451	205	58	31	3155
Gross Pond Evap	Inch	1.5	1.87	3.86	4.65	5.01	6.71	6.1	5.38	4.33	2.32	1.71	1.32	44.76
Net Pond Evap	Inch	1.33	1.62	3.39	4.11	1.81	5.86	4.78	5.12	4.08	1.78	1.34	1.28	36.5
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	29.35	27.04	42.11	47.57	60.85	71.28	73.56	70.52	65.43	47.61	36.44	29.51	50.11
Ref date as of 12/31/2018	Total Precip "	0.47	0.67	1.02	0.79	3.04	2.57	1.47	0.77	0.25	1	0.56	0.14	12.75
Site Type: Turf	Total Alfalfa ETr "	1.47	2.12	4.7	5.83	6.5	8.38	7.88	7.13	5.74	3.18	2.15	1.67	56.75
Total Growing Degee Days from March 1		0	0	155	228	396	563	669	603	484	225	65	26	3414
Gross Pond Evap	Inch	1.23	1.78	3.95	4.9	5.46	7.04	6.62	5.99	4.82	2.67	1.81	1.4	47.67
Net Pond Evap	Inch	0.91	1.31	3.23	4.34	3.33	5.24	5.59	5.45	4.65	1.97	1.41	1.3	38.73
Loveland	Avg. Temp ° F	31.18	28.74	42.38	47.7	60.46	70.62	72.9	70.59	65.45	47.67	36.88	30.55	50.43
Ref date as of 12/31/2018	Total Precip "	0.22	0.95	0.87	0.93	3.42	1.27	1.97	0.88	0.15	1.21	0.56	0.09	12.52
Site Type: Turf	Total Alfalfa ETr "	1.69	2.24	4.4	5.51	6.07	7.91	7.09	6.43	5.18	2.86	2.01	1.7	53.09
Total Growing Degee Days from March 1		0	0	156	217	391	557	670	626	495	232	63	39	3446
Gross Pond Evap	Inch	1.42	1.88	3.7	4.63	5.1	6.64	5.96	5.4	4.35	2.4	1.69	1.43	44.6
Net Pond Evap	Inch	1.27	1.22	3.09	3.98	2.7	5.76	4.58	4.79	4.25	1.56	1.3	1.37	35.87
Berthoud	Avg. Temp ° F	31.95	28.3	42.35	47.43	60.1	70.57	72.31	69.98	65.13	47.07	36.48	30.24	50.16
Ref date as of 12/31/2018	Total Precip "	0.31	0.84	1.05	0.86	3.76	1.69	2.03	0.78	0.13	0.93	0.52	0.09	12.99
Site Type: Turf	Total Alfalfa ETr "	1.82	2.31	4.66	5.65	6.32	8.49	7.7	7.16	5.66	3.03	2.22	1.79	56.81
Total Growing Degee Days from March 1		0	0	128	193	363	553	663	619	472	195	53	22	3261
Gross Pond Evap	Inch	1.53	1.94	3.91	4.75	5.31	7.13	6.47	6.01	4.75	2.55	1.86	1.5	47.71
Net Pond Evap	Inch	1.31	1.35	3.18	4.14	2.68	5.95	5.05	5.47	4.66	1.89	1.5	1.44	38.62
Longmont West	Avg. Temp ° F	32.96	30.13	43.22	48.63	60.67	71.58	73.62	70.52	65.17	47.5	37.35	30.71	51.01
Ref date as of 12/31/2018	Total Precip "	0.22	0.21	1.29	0.89	4.02	0.98	1.81	1.17	0.32	1.25	0.38	0.04	12.58
Site Type: Turf	Total Alfalfa ETr "	1.76	2.25	4.36	5.46	6.09	7.77	7.44	6.63	5.04	2.82	1.94	1.47	53.03
Total Growing Degee Days from March 1		0	0	139	202	364	558	667	614	472	207	68	31	3322
Gross Pond Evap	Inch	1.48	1.89	3.66	4.59	5.12	6.53	6.25	5.57	4.23	2.37	1.63	1.23	44.55
Net Pond Evap	Inch	1.32	1.74	2.76	3.96	2.3	5.84	4.98	4.75	4.01	1.49	1.36	1.21	35.72
Fort Lupton	Avg. Temp ° F	32.22	28.66	42.67	48.44	61.29	71.13	71.24	67.8	63.39	48.32	37.91	31.3	50.36
Ref date as of 12/31/2018	Total Precip "	0.44	0.46	0.77	0.97	2.64	2.09	1.51	1.38	0.17	0.96	0.36	0.07	11.82
Site Type: Turf	Total Alfalfa ETr "	2.03	2.46	5.17	6.43	7.02	9.27	8.71	7.77	6.35	3.57	2.5	1.99	63.27
Total Growing Degee Days from March 1		0	0	146	222	398	567	617	558	448	217	76	37	3286
Gross Pond Evap	Inch	1.71	2.07	4.34	5.4	5.9	7.79	7.32	6.53	5.33	3	2.1	1.67	53.16
Net Pond Evap	Inch	1.4	1.74	3.8	4.72	4.05	6.32	6.26	5.56	5.22	2.33	1.85	1.62	44.87
Boulder NW	Avg. Temp ° F	35.59	29.71	41.45	47	59.51	69.84	72.13	69.62	64.84	47.05	37.37	32.31	50.54
Ref date as of 12/31/2018	Total Precip "	0.33	0.49	1.57	1.06	4.5	1.75	1.6	0.67	0.66	2.22	0.7	0.15	15.7
Site Type: Turf	Total Alfalfa ETr "	2.24	2.3	4.15	5.2	5.79	7.54	7.25	6.67	5.32	2.87	2.39	1.86	53.58
Total Growing Degee Days from March 1		0	0	117	190	355	525	630	583	471	189	60	34	3154
Gross Pond Evap	Inch	1.88	1.93	3.49	4.37	4.86	6.33	6.09	5.6	4.47	2.41	2.01	1.56	45
Net Pond Evap	Inch	1.65	1.59	2.39	3.63	1.71	5.11	4.97	5.13	4.01	0.86	1.52	1.46	34.03
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	38.18	31.76	43.52	48.53	59.81	70.28	71.49	70.3	65.65	48.54	39.95	34.87	51.91
Ref date as of 12/31/2018	Total Precip "	0.15	0.29	1.5	1.09	4.61	1.38	1.37	0.74	1.13	1.83	0.71	0.11	14.91
Site Type: Turf	Total Alfalfa ETr "	2.52	2.59	4.6	5.61	5.86	8.08	7.48	7.15	5.56	3.17	2.71	2.14	57.47
Total Growing Degee Days from March 1		0	0	107	179	345	504	609	577	455	184	57	29	3046
Gross Pond Evap	Inch	2.12	2.18	3.86	4.71	4.92	6.79	6.28	6.01	4.67	2.66	2.28	1.8	48.28
Net Pond Evap	Inch	2.01	1.97	2.81	3.95	1.7	5.82	5.32	5.49	3.88	1.38	1.78	1.72	37.83
Greeley04	Avg. Temp ° F	28.22	25.93	41.6	46.51	60.52	70.55	71.94	68.73	63.25	46.15	34.5	27.4	48.78
Ref date as of 12/31/2018	Total Precip "	0.04	0.28	0.82	0.69	2.99	1.62	0.44	0.38	0.08	0.49	0.05	0.06	7.94
Site Type: Fully irrigated	Total Alfalfa ETr "	2.06	2.49	5.76	7.23	7.1	10.1	8.46	7.3	6.3	3.72	2.57	2.33	65.42
Total Growing Degee Days from March 1		0	0	151	218	393	551	641	571	457	211	59	25	3277
Gross Pond Evap	Inch	1.73	2.09	4.84	6.07	5.96	8.48	7.11	6.13	5.29	3.12	2.16	1.96	54.94
Net Pond Evap	Inch	1.7	1.9	4.26	5.59	3.87	7.35	6.8	5.87	5.24	2.78	2.12	1.92	49.4