Oglala Lakota College - Piya Wiconi
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Oglala Lakota College - Piya Wiconi clear sky chart from 2005-11-06 to 2024-11-28.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	8% 6% 2 5% 3 4 4 3 5% 8% 52%	105387
	Night	7% 7% 2 6% 4 4 4 4 6% 7% 50%	102835
Transparency	Day	29% 7% 14% 27% 18% 5%	105131
	Night	32% 7% 14% 26% 17% 4	102681
Seeing	Day	10% 8% 30% 32% 15% 3	15961
	Night	10% 7% 38% 36% 9%	25938

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	2 6% 2 9% 5% 5% 5% 4 7% 9% 46%	2538
	11th to 20th	Day	4 8% 4 9% 4 5% 5% 4 6% 9% 41%	2540
	21st to end	Day	3 6% 2 6% 4 4 4 4 5% 7% 54%	2794
February	1st to 10th	Day	7% 14% 4 10% 5% 5% 4 3 5% 6% 38%	1704
	11th to 20th	Day	8% 10% 4 7% 5% 4 5% 5% 5% 6% 42%	1849
	21st to end	Day	6% 9% 3 7% 4 4 4 4 5% 8% 46%	1570
March	1st to 10th	Day	6% 7% 2 5% 4 3 3 3 5% 7% 54%	3130
	11th to 20th	Day	7% 6% 1 4 3 4 4 3 5% 7% 56%	3280
	21st to end	Day	14% 11% 4 9% 3 4 4 3 5% 8% 35%	4099
April	1st to 10th	Day	13% 10% 2 6% 4 3 4 3 5% 7% 44%	2280
	11th to 20th	Day	15% 10% 2 7% 3 4 4 4 5% 7% 39%	2251
	21st to end	Day	14% 9% 2 5% 4 3 4 3 6% 7% 43%	2460
May	1st to 10th	Day	16% 8% 3 7% 4 4 4 3 5% 7% 40%	4120
	11th to 20th	Day	10% 6% 2 5% 4 4 4 3 6% 8% 48%	4312
	21st to end	Day	12% 6% 3 6% 4 4 4 4 5% 7% 44%	4825
June	1st to 10th	Day	9% 4 1 3 4 4 4 4 7% 10% 50%	2660
	11th to 20th	Day	9% 4 2 4 3 3 4 4 8% 8% 52%	2660
	21st to end	Day	5% 3 1 4 3 3 4 3 6% 8% 60%	2660
July	1st to 10th	Day	5% 4 2 4 3 4 4 5% 6% 8% 54%	4430
	11th to 20th	Day	4 2 2 3 3 3 4 4 7% 11% 59%	4430
	21st to end	Day	3 2 1 3 3 3 4 4 6% 8% 62%	4802
August	1st to 10th	Day	5% 4 2 6% 4 4 4 4 6% 9% 53%	4324
	11th to 20th	Day	5% 4 2 5% 3 3 4 4 6% 9% 55%	3925
	21st to end	Day	4 3 1 4 3 3 3 3 5% 7% 62%	4180
September	1st to 10th	Day	6% 4 1 4 3 3 3 3 4 6% 65%	2280
	11th to 20th	Day	7% 3 1 3 3 2 3 3 4 6% 65%	2147
	21st to end	Day	9% 4 1 3 2 2 3 2 3 6% 63%	2090
October	1st to 10th	Day	7% 4 1 2 2 2 2 2 3 4 71%	3454
	11th to 20th	Day	10% 4 1 4 3 2 2 2 4 8% 59%	3009
	21st to end	Day	9% 9% 2 5% 4 4 3 3 4 7% 49%	3091
November	1st to 10th	Day	7% 6% 2 4 3 4 4 4 6% 7% 53%	1763
	11th to 20th	Day	5% 7% 2 6% 4 4 4 4 5% 7% 52%	1800
	21st to end	Day	5% 8% 3 5% 4 3 4 3 6% 7% 52%	1690
December	1st to 10th	Day	5% 9% 2 7% 4 4 4 4 5% 8% 48%	1520
	11th to 20th	Day	4 7% 3 5% 4 3 4 3 5% 9% 54%	1926
	21st to end	Day	8% 15% 4 6% 4 4 4 3 4 6% 43%	2794
January	1st to 10th	Night	3 9% 4 10% 5% 4 4 3 5% 7% 45%	4417
	11th to 20th	Night	3 8% 3 11% 6% 6% 5% 4 5% 7% 41%	4430
	21st to end	Night	3 6% 3 6% 4 4 4 3 5% 8% 52%	4873
February	1st to 10th	Night	9% 12% 4 8% 6% 4 4 3 4 6% 40%	2490
	11th to 20th	Night	6% 10% 3 8% 6% 4 4 4 6% 7% 43%	2218
	21st to end	Night	6% 9% 3 7% 5% 4 4 3 5% 6% 48%	1884
March	1st to 10th	Night	8% 9% 3 7% 4 4 5% 3 5% 6% 46%	3734
	11th to 20th	Night	6% 7% 2 4 3 4 4 4 5% 9% 51%	3686
	21st to end	Night	10% 9% 4 10% 6% 5% 5% 4 6% 8% 34%	3526
April	1st to 10th	Night	13% 9% 3 5% 4 3 4 4 5% 6% 43%	1900
	11th to 20th	Night	14% 8% 2 5% 5% 4 4 4 6% 7% 41%	1877
	21st to end	Night	14% 7% 2 5% 5% 4 5% 3 6% 8% 41%	1720
May	1st to 10th	Night	13% 8% 2 7% 5% 5% 4 4 6% 7% 39%	2850
	11th to 20th	Night	9% 4 1 4 3 2 3 4 6% 9% 55%	2590
	21st to end	Night	14% 6% 2 6% 4 5% 4 4 6% 7% 43%	2762
June	1st to 10th	Night	9% 4 2 5% 3 4 4 4 7% 9% 50%	1520
	11th to 20th	Night	13% 4 1 4 4 4 3 4 7% 7% 49%	1520
	21st to end	Night	5% 3 2 4 4 4 4 5% 8% 8% 53%	1520
July	1st to 10th	Night	6% 3 1 4 4 4 5% 4 6% 8% 54%	2540
	11th to 20th	Night	3 3 1 4 3 4 4 4 7% 8% 59%	2540
	21st to end	Night	4 3 2 5% 4 4 4 3 6% 8% 59%	2761
August	1st to 10th	Night	6% 4 2 6% 5% 5% 6% 5% 8% 10% 44%	2615
	11th to 20th	Night	5% 6% 1 6% 4 4 5% 3 7% 8% 51%	2912
	21st to end	Night	3 4 2 5% 4 5% 5% 4 6% 7% 56%	3487
September	1st to 10th	Night	7% 4 1 4 3 2 3 3 4 5% 62%	1900
	11th to 20th	Night	6% 4 1 4 3 3 3 2 5% 6% 62%	2033
	21st to end	Night	9% 5% 1 4 3 3 3 2 4 5% 61%	2090
October	1st to 10th	Night	8% 3 1 3 2 2 2 2 3 4 71%	3503
	11th to 20th	Night	8% 4 1 4 2 3 3 3 5% 7% 59%	3887
	21st to end	Night	10% 7% 2 5% 3 3 3 3 6% 8% 48%	4467
November	1st to 10th	Night	8% 6% 2 5% 4 3 4 4 5% 8% 51%	2535
	11th to 20th	Night	6% 7% 2 6% 5% 5% 4 4 5% 7% 49%	2600
	21st to end	Night	5% 7% 2 5% 4 4 4 4 6% 7% 52%	2644
December	1st to 10th	Night	5% 8% 3 7% 5% 4 4 3 6% 7% 48%	2660
	11th to 20th	Night	4 7% 3 6% 4 4 5% 4 6% 8% 50%	3271
	21st to end	Night	7% 12% 4 7% 3 4 4 3 5% 6% 44%	4873

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	31% 9% 18% 26% 14% 1	2539
	11th to 20th	Day	37% 8% 18% 25% 11% 2	2540
	21st to end	Day	27% 8% 22% 29% 11% 3	2794
February	1st to 10th	Day	46% 7% 13% 20% 12% 2	1704
	11th to 20th	Day	39% 8% 15% 21% 13% 4	1859
	21st to end	Day	34% 8% 14% 28% 13% 3	1570
March	1st to 10th	Day	28% 5% 12% 26% 23% 5%	3130
	11th to 20th	Day	25% 8% 17% 38% 11% 1	3280
	21st to end	Day	46% 8% 18% 22% 6%	4099
April	1st to 10th	Day	39% 6% 15% 26% 10% 3	2280
	11th to 20th	Day	42% 7% 14% 21% 13% 2	2254
	21st to end	Day	39% 7% 14% 28% 11% 1	2460
May	1st to 10th	Day	40% 9% 15% 22% 11% 3	4120
	11th to 20th	Day	29% 10% 16% 30% 13% 2	4316
	21st to end	Day	35% 10% 17% 27% 10% 1	4825
June	1st to 10th	Day	27% 10% 20% 27% 15% 2	2660
	11th to 20th	Day	27% 8% 18% 27% 16% 5%	2660
	21st to end	Day	20% 6% 13% 31% 23% 7%	2660
July	1st to 10th	Day	25% 7% 12% 29% 25% 3	4361
	11th to 20th	Day	19% 5% 12% 33% 23% 8%	4355
	21st to end	Day	18% 5% 11% 24% 27% 15%	4651
August	1st to 10th	Day	27% 6% 16% 24% 21% 6%	4309
	11th to 20th	Day	26% 7% 15% 28% 19% 5%	3964
	21st to end	Day	21% 4 11% 23% 27% 14%	4179
September	1st to 10th	Day	21% 4 8% 28% 27% 11%	2280
	11th to 20th	Day	21% 5% 10% 29% 25% 10%	2147
	21st to end	Day	24% 4 8% 31% 28% 5%	2090
October	1st to 10th	Day	20% 3 8% 19% 32% 18%	3454
	11th to 20th	Day	25% 3 13% 35% 21% 3	3009
	21st to end	Day	35% 5% 12% 29% 15% 4	3091
November	1st to 10th	Day	28% 6% 16% 27% 19% 5%	1763
	11th to 20th	Day	28% 7% 12% 26% 21% 5%	1800
	21st to end	Day	30% 5% 15% 32% 15% 3	1690
December	1st to 10th	Day	33% 6% 16% 28% 16% 2	1520
	11th to 20th	Day	26% 6% 21% 34% 12% 1	1924
	21st to end	Day	41% 6% 10% 29% 13% 1	2794
January	1st to 10th	Night	36% 8% 13% 29% 13% 1	4417
	11th to 20th	Night	40% 9% 14% 25% 12% 1	4430
	21st to end	Night	28% 7% 21% 28% 14% 1	4873
February	1st to 10th	Night	44% 7% 16% 20% 12% 2	2490
	11th to 20th	Night	39% 7% 15% 25% 12% 3	2218
	21st to end	Night	36% 6% 15% 25% 14% 4	1884
March	1st to 10th	Night	34% 8% 12% 23% 21% 1	3734
	11th to 20th	Night	27% 8% 18% 28% 18% 1	3686
	21st to end	Night	44% 10% 17% 22% 7% 1	3526
April	1st to 10th	Night	40% 8% 14% 23% 13% 2	1900
	11th to 20th	Night	39% 9% 13% 21% 15% 3	1877
	21st to end	Night	39% 9% 14% 24% 13% 1	1720
May	1st to 10th	Night	38% 12% 14% 22% 12% 3	2850
	11th to 20th	Night	24% 8% 19% 37% 11% 2	2591
	21st to end	Night	37% 10% 15% 25% 12% 1	2762
June	1st to 10th	Night	29% 8% 20% 26% 15% 1	1520
	11th to 20th	Night	32% 8% 19% 24% 15% 3	1520
	21st to end	Night	23% 9% 16% 29% 19% 4	1520
July	1st to 10th	Night	26% 7% 14% 24% 24% 5%	2500
	11th to 20th	Night	22% 5% 15% 29% 21% 8%	2492
	21st to end	Night	22% 5% 13% 24% 27% 9%	2674
August	1st to 10th	Night	32% 7% 17% 21% 18% 5%	2607
	11th to 20th	Night	30% 6% 17% 24% 19% 4	2939
	21st to end	Night	25% 6% 14% 21% 25% 9%	3487
September	1st to 10th	Night	23% 4 9% 27% 27% 9%	1900
	11th to 20th	Night	22% 5% 13% 25% 27% 8%	2033
	21st to end	Night	26% 4 8% 28% 25% 9%	2090
October	1st to 10th	Night	19% 4 6% 19% 31% 21%	3503
	11th to 20th	Night	25% 4 11% 34% 22% 4	3887
	21st to end	Night	33% 4 12% 27% 17% 6%	4467
November	1st to 10th	Night	31% 5% 15% 24% 19% 6%	2535
	11th to 20th	Night	32% 6% 12% 26% 19% 5%	2600
	21st to end	Night	29% 6% 15% 28% 20% 3	2644
December	1st to 10th	Night	34% 6% 15% 26% 17% 3	2660
	11th to 20th	Night	30% 6% 15% 35% 12% 2	3272
	21st to end	Night	39% 7% 12% 29% 11% 2	4873

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	4 7% 42% 27% 15% 4	270
	11th to 20th	Day	12% 12% 34% 35% 7%	270
	21st to end	Day	9% 11% 44% 27% 7% 1	297
February	1st to 10th	Day	11% 11% 44% 31% 3	270
	11th to 20th	Day	13% 11% 44% 27% 4 1	270
	21st to end	Day	8% 14% 48% 24% 4 1	225
March	1st to 10th	Day	8% 14% 40% 28% 9% 1	270
	11th to 20th	Day	10% 9% 36% 31% 13% 1	270
	21st to end	Day	17% 13% 32% 25% 11% 2	466
April	1st to 10th	Day	16% 17% 35% 26% 6% 1	460
	11th to 20th	Day	19% 15% 38% 24% 5%	452
	21st to end	Day	20% 10% 26% 33% 11% 1	640
May	1st to 10th	Day	16% 11% 27% 29% 14% 3	653
	11th to 20th	Day	20% 6% 24% 29% 16% 4	675
	21st to end	Day	15% 8% 28% 32% 13% 4	734
June	1st to 10th	Day	6% 5% 26% 34% 20% 8%	680
	11th to 20th	Day	11% 7% 32% 34% 14% 4	680
	21st to end	Day	6% 6% 27% 35% 21% 3	680
July	1st to 10th	Day	5% 2 24% 39% 24% 5%	671
	11th to 20th	Day	5% 3 24% 45% 18% 4	668
	21st to end	Day	4 3 22% 40% 27% 4	739
August	1st to 10th	Day	6% 3 23% 41% 24% 4	676
	11th to 20th	Day	5% 4 21% 41% 23% 6%	601
	21st to end	Day	4 6% 22% 35% 26% 7%	539
September	1st to 10th	Day	6% 6% 23% 36% 25% 5%	490
	11th to 20th	Day	8% 3 24% 31% 25% 8%	357
	21st to end	Day	11% 11% 27% 29% 17% 5%	300
October	1st to 10th	Day	15% 7% 26% 26% 15% 10%	300
	11th to 20th	Day	12% 12% 34% 28% 12% 3	300
	21st to end	Day	12% 12% 38% 25% 11% 2	330
November	1st to 10th	Day	10% 11% 40% 24% 13% 2	300
	11th to 20th	Day	10% 13% 41% 27% 8% 1	300
	21st to end	Day	10% 9% 36% 33% 12%	291
December	1st to 10th	Day	9% 14% 43% 25% 9% 1	270
	11th to 20th	Day	9% 10% 49% 27% 5% 1	270
	21st to end	Day	14% 12% 40% 26% 7% 1	297
January	1st to 10th	Night	8% 10% 41% 31% 9% 1	950
	11th to 20th	Night	8% 11% 43% 31% 6%	950
	21st to end	Night	10% 9% 42% 33% 6%	1045
February	1st to 10th	Night	14% 9% 46% 26% 6%	827
	11th to 20th	Night	11% 7% 46% 31% 5%	744
	21st to end	Night	10% 8% 47% 29% 6%	628
March	1st to 10th	Night	12% 9% 39% 36% 5%	760
	11th to 20th	Night	10% 7% 42% 34% 7% 1	698
	21st to end	Night	14% 10% 35% 32% 8%	627
April	1st to 10th	Night	15% 10% 39% 32% 3	570
	11th to 20th	Night	18% 10% 39% 29% 3	563
	21st to end	Night	16% 11% 32% 32% 9%	570
May	1st to 10th	Night	15% 8% 32% 33% 12% 1	570
	11th to 20th	Night	18% 6% 28% 34% 12% 1	561
	21st to end	Night	16% 8% 36% 31% 8%	617
June	1st to 10th	Night	9% 5% 32% 39% 13% 1	570
	11th to 20th	Night	12% 6% 39% 35% 8%	570
	21st to end	Night	5% 4 35% 46% 10%	570
July	1st to 10th	Night	5% 2 30% 44% 18% 1	555
	11th to 20th	Night	5% 3 33% 50% 10%	552
	21st to end	Night	4 2 30% 50% 13%	624
August	1st to 10th	Night	4 3 28% 52% 13%	567
	11th to 20th	Night	4 4 29% 47% 15% 1	564
	21st to end	Night	4 3 31% 49% 13%	627
September	1st to 10th	Night	8% 3 30% 48% 11% 1	570
	11th to 20th	Night	8% 5% 31% 41% 14% 1	570
	21st to end	Night	12% 5% 34% 38% 11% 1	570
October	1st to 10th	Night	17% 7% 28% 37% 12%	580
	11th to 20th	Night	12% 6% 36% 36% 10%	818
	21st to end	Night	14% 7% 35% 34% 10% 1	1045
November	1st to 10th	Night	10% 6% 41% 34% 7% 1	975
	11th to 20th	Night	9% 8% 44% 33% 6%	1000
	21st to end	Night	8% 7% 41% 37% 7%	986
December	1st to 10th	Night	9% 9% 48% 29% 5%	950
	11th to 20th	Night	7% 7% 47% 32% 6%	950
	21st to end	Night	14% 11% 42% 27% 6%	1045

Page generated at 2024-11-24 23:22:19. Version ac07

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