NASA Surface meteorology and Solar Energy

**Monthly Averaged Radiation Incident On An Equator-Pointed Tilted Surface (kWh/m²/day)**
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual Average
SSE HRZ	0.76	1.57	2.66	3.70	4.94	4.94	4.84	4.23	2.66	1.45	0.77	0.56	2.76
K	0.41	0.46	0.46	0.44	0.47	0.43	0.44	0.46	0.40	0.35	0.34	0.39	0.42
Diffuse	0.49	0.90	1.47	2.07	2.57	2.73	2.68	2.24	1.51	0.87	0.52	0.38	1.54
Direct	1.36	2.33	3.00	3.30	4.31	3.90	3.88	3.82	2.63	1.79	1.16	1.08	2.72
Tilt 0	0.75	1.56	2.63	3.68	4.96	4.99	4.87	4.19	2.61	1.42	0.75	0.56	2.76
Tilt 39	1.38	2.44	3.40	4.04	4.91	4.70	4.70	4.45	3.13	2.00	1.24	1.10	3.13
Tilt 54	1.51	2.57	3.41	3.85	4.51	4.26	4.27	4.18	3.07	2.06	1.32	1.22	3.02
Tilt 69	1.55	2.56	3.26	3.50	4.00	3.73	3.76	3.74	2.88	2.02	1.34	1.27	2.80
Tilt 90	1.47	2.34	2.79	2.80	3.02	2.79	2.83	2.92	2.39	1.80	1.25	1.22	2.30
OPT	1.55	2.58	3.42	4.06	5.13	5.04	4.97	4.51	3.13	2.06	1.34	1.27	3.26
OPT ANG	69.0	61.0	48.0	31.0	18.0	10.0	15.0	27.0	41.0	55.0	65.0	72.0	42.5

**Minimum Available Insolation Over A Consecutive-day Period (%)**
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Min/1 day	30.2	24.8	27.8	20.5	19.8	11.9	22.0	21.5	18.4	10.3	3.89	50.0
Min/3 day	42.9	36.3	35.0	33.2	34.8	35.5	30.9	31.9	37.3	25.5	30.3	54.1
Min/7 day	46.0	46.8	45.9	46.3	48.3	54.9	46.5	51.0	54.2	39.5	41.7	63.5
Min/14 day	57.1	55.5	52.6	62.1	61.0	65.1	64.9	70.8	65.5	49.1	48.3	72.9
Min/21 day	58.2	63.6	62.8	69.3	70.3	75.4	69.2	78.8	66.4	55.7	53.8	75.4
Min/Month	82.8	73.8	67.6	80.8	80.5	85.2	77.7	83.4	73.6	70.3	59.7	80.3

**Equivalent Number Of NO-SUN Or BLACK Days (days)**
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1 day	0.69	0.75	0.72	0.79	0.80	0.88	0.77	0.78	0.81	0.89	0.96	0.50
3 day	1.71	1.91	1.94	2.00	1.95	1.93	2.07	2.04	1.87	2.23	2.09	1.37
7 day	3.77	3.71	3.78	3.75	3.61	3.15	3.74	3.42	3.19	4.23	4.07	2.55
14 day	6.00	6.21	6.62	5.30	5.44	4.87	4.90	4.07	4.81	7.11	7.23	3.78
21 day	8.77	7.64	7.80	6.44	6.23	5.16	6.45	4.43	7.05	9.28	9.68	5.16
Month	5.30	7.31	10.0	5.75	6.02	4.43	6.90	5.13	7.89	9.19	12.0	6.08

**Monthly Averaged Wind Speed At 50 m Above The Surface Of The Earth (m/s)**
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual Average
10-year Average	4.48	4.12	4.22	4.12	3.92	3.71	3.80	3.84	4.21	4.30	4.29	4.26	4.10

**Minimum And Maximum Difference From Monthly Averaged Wind Speed At 50 m (%)**
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual Average
Minimum	-15	-15	-12	-10	-8	-12	-9	-12	-17	-8	-12	-14	-12
Maximum	20	16	36	10	11	10	7	8	11	13	10	13	14

It is recommended that users of these wind data review the SSE Methodology. The user may wish to correct for biases as well as local effects within the selected grid region.

All height measurements are from the soil, water, or ice/snow surface instead of "effective" surface, which is usually taken to be near the tops of vegetated canopies.

Difference Between The Average Wind Speed At 10 m Above The Surface Of The Earth And The Average Wind speed At 50 m Above The Surface Of The Earth (%)
***Vegetation type*** Rough bare soil
Lat 54 Lon 27.5	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual Average
10-year Average	-30	-30	-30	-30	-30	-30	-30	-30	-30	-30	-30	-30	-30