Badlands National Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Badlands National Park clear sky chart from 2005-11-06 to 2025-05-26.

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 6% 4 3 4 3 5% 7% 51%	117778
	Night	8% 7% 2 6% 4 4 4 4 5% 7% 49%	120321
Transparency	Day	33% 3 13% 29% 18% 4	117522
	Night	35% 3 13% 28% 18% 4	120167
Seeing	Day	12% 6% 27% 32% 18% 4	16627
	Night	11% 6% 32% 39% 11% 1	26678

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	4 10% 6% 13% 6% 4 3 3 5% 6% 40%	3638
	11th to 20th	Day	4 9% 4 12% 5% 4 4 3 5% 7% 43%	3640
	21st to end	Day	2 6% 3 10% 4 4 5% 3 4 6% 53%	4004
February	1st to 10th	Day	9% 11% 4 8% 6% 4 5% 3 5% 6% 38%	1770
	11th to 20th	Day	6% 11% 4 6% 5% 3 4 3 5% 7% 44%	1949
	21st to end	Day	6% 8% 3 8% 5% 4 4 4 5% 7% 47%	1650
March	1st to 10th	Day	7% 8% 2 5% 4 3 3 3 4 6% 55%	4500
	11th to 20th	Day	7% 6% 1 4 3 3 3 2 6% 8% 57%	4713
	21st to end	Day	16% 10% 3 7% 4 4 4 3 5% 8% 36%	5831
April	1st to 10th	Day	14% 8% 3 5% 3 3 4 3 5% 8% 44%	2400
	11th to 20th	Day	14% 7% 3 6% 4 4 4 4 5% 7% 42%	2384
	21st to end	Day	14% 7% 3 5% 4 4 4 4 6% 8% 43%	2600
May	1st to 10th	Day	17% 8% 2 6% 4 4 4 3 5% 6% 40%	4250
	11th to 20th	Day	11% 5% 2 5% 4 3 4 3 5% 8% 49%	4445
	21st to end	Day	15% 6% 2 6% 4 3 4 4 6% 7% 43%	4897
June	1st to 10th	Day	8% 4 1 4 3 4 4 4 6% 9% 52%	2660
	11th to 20th	Day	8% 4 2 4 3 3 4 4 7% 8% 53%	2660
	21st to end	Day	5% 3 1 3 3 3 3 4 6% 7% 60%	2660
July	1st to 10th	Day	5% 4 1 5% 3 4 5% 5% 6% 8% 54%	4430
	11th to 20th	Day	4 3 1 4 2 3 3 3 6% 9% 61%	4430
	21st to end	Day	3 2 1 3 3 3 4 4 6% 9% 62%	4802
August	1st to 10th	Day	5% 4 2 5% 4 4 4 4 6% 9% 52%	4319
	11th to 20th	Day	7% 4 2 4 3 3 5% 3 6% 9% 53%	3984
	21st to end	Day	4 3 1 3 3 3 3 3 5% 8% 64%	4180
September	1st to 10th	Day	6% 3 1 4 3 3 3 3 3 7% 64%	2280
	11th to 20th	Day	8% 3 1 4 2 3 3 2 4 7% 63%	2138
	21st to end	Day	10% 3 1 3 2 2 2 3 4 6% 63%	2090
October	1st to 10th	Day	7% 4 1 3 2 1 2 2 3 4 70%	3480
	11th to 20th	Day	9% 4 2 5% 2 2 3 2 4 7% 59%	2976
	21st to end	Day	11% 7% 2 5% 4 4 4 3 5% 7% 48%	3091
November	1st to 10th	Day	7% 5% 2 5% 3 5% 4 4 6% 6% 53%	1763
	11th to 20th	Day	6% 6% 2 7% 4 4 3 4 4 6% 54%	1800
	21st to end	Day	4 9% 3 5% 4 3 3 4 5% 8% 51%	1714
December	1st to 10th	Day	4 8% 4 8% 5% 4 4 3 6% 8% 47%	2620
	11th to 20th	Day	3 7% 3 7% 4 4 4 3 6% 7% 52%	3026
	21st to end	Day	9% 12% 2 6% 4 4 4 2 4 6% 46%	4004
January	1st to 10th	Night	8% 11% 4 11% 6% 4 4 3 4 5% 39%	6327
	11th to 20th	Night	3 9% 3 11% 6% 6% 5% 3 5% 5% 43%	6340
	21st to end	Night	2 6% 3 8% 4 4 4 3 5% 6% 55%	6974
February	1st to 10th	Night	9% 12% 4 9% 5% 4 4 4 5% 6% 39%	2643
	11th to 20th	Night	5% 10% 4 8% 5% 5% 5% 5% 6% 5% 41%	2338
	21st to end	Night	7% 8% 2 6% 6% 4 3 4 5% 7% 48%	1980
March	1st to 10th	Night	10% 7% 3 5% 4 3 4 3 4 6% 50%	5374
	11th to 20th	Night	7% 6% 2 4 3 3 3 4 5% 9% 53%	5258
	21st to end	Night	14% 10% 3 8% 5% 4 5% 4 6% 7% 34%	5102
April	1st to 10th	Night	13% 8% 3 6% 4 4 5% 4 4 6% 43%	2000
	11th to 20th	Night	15% 6% 2 6% 5% 4 3 4 5% 6% 43%	1963
	21st to end	Night	15% 7% 3 5% 4 4 4 4 5% 8% 42%	1800
May	1st to 10th	Night	14% 6% 2 6% 5% 5% 5% 5% 6% 7% 40%	2940
	11th to 20th	Night	9% 4 1 4 3 3 4 3 6% 8% 54%	2676
	21st to end	Night	16% 6% 2 6% 5% 4 4 4 5% 7% 42%	2806
June	1st to 10th	Night	8% 5% 1 4 3 4 4 4 7% 9% 52%	1520
	11th to 20th	Night	11% 3 2 3 5% 4 4 4 7% 7% 49%	1520
	21st to end	Night	6% 3 2 4 4 4 4 4 6% 8% 56%	1520
July	1st to 10th	Night	7% 3 1 4 3 3 5% 5% 6% 8% 55%	2540
	11th to 20th	Night	4 2 1 4 3 3 3 4 7% 10% 60%	2540
	21st to end	Night	3 4 2 3 3 4 4 4 6% 8% 60%	2761
August	1st to 10th	Night	5% 5% 2 6% 4 4 5% 5% 7% 9% 47%	2619
	11th to 20th	Night	7% 5% 2 5% 4 4 4 4 6% 8% 50%	2852
	21st to end	Night	3 3 1 5% 4 4 5% 4 6% 8% 57%	3487
September	1st to 10th	Night	7% 3 2 4 2 2 3 2 4 6% 64%	1900
	11th to 20th	Night	7% 3 1 4 3 2 3 3 6% 7% 60%	2042
	21st to end	Night	10% 3 1 3 3 2 3 2 3 6% 62%	2090
October	1st to 10th	Night	8% 3 1 3 2 2 2 2 3 4 70%	3480
	11th to 20th	Night	8% 4 1 4 2 2 4 3 5% 7% 59%	3917
	21st to end	Night	10% 6% 2 4 3 3 4 4 5% 7% 51%	4467
November	1st to 10th	Night	8% 6% 2 6% 4 4 4 4 6% 8% 49%	2535
	11th to 20th	Night	6% 8% 2 7% 5% 4 4 3 5% 5% 51%	2600
	21st to end	Night	6% 7% 2 5% 4 4 4 4 6% 7% 52%	2685
December	1st to 10th	Night	4 7% 2 6% 4 4 5% 4 6% 6% 51%	4570
	11th to 20th	Night	4 7% 2 6% 5% 5% 5% 4 6% 8% 47%	5181
	21st to end	Night	10% 10% 3 8% 4 4 4 4 6% 7% 42%	6974

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	47% 2 16% 27% 8%	3639
	11th to 20th	Day	42% 4 15% 22% 15% 2	3640
	21st to end	Day	34% 3 16% 32% 13% 3	4004
February	1st to 10th	Day	48% 3 12% 21% 13% 2	1770
	11th to 20th	Day	40% 3 17% 21% 14% 4	1959
	21st to end	Day	37% 3 14% 28% 15% 3	1650
March	1st to 10th	Day	33% 2 8% 30% 24% 4	4500
	11th to 20th	Day	27% 2 13% 37% 20% 1	4713
	21st to end	Day	48% 4 17% 21% 10%	5831
April	1st to 10th	Day	39% 4 14% 30% 11% 3	2400
	11th to 20th	Day	42% 4 12% 24% 16% 3	2387
	21st to end	Day	41% 3 16% 30% 11% 1	2600
May	1st to 10th	Day	45% 3 11% 26% 13% 3	4250
	11th to 20th	Day	35% 2 14% 32% 14% 3	4449
	21st to end	Day	41% 3 14% 29% 12% 1	4897
June	1st to 10th	Day	30% 4 20% 29% 15% 3	2660
	11th to 20th	Day	28% 4 18% 28% 18% 4	2660
	21st to end	Day	22% 3 12% 34% 23% 6%	2660
July	1st to 10th	Day	26% 5% 13% 30% 23% 3	4361
	11th to 20th	Day	20% 4 11% 32% 24% 9%	4355
	21st to end	Day	18% 4 11% 27% 30% 10%	4651
August	1st to 10th	Day	27% 4 17% 23% 22% 7%	4304
	11th to 20th	Day	28% 6% 14% 29% 18% 4	4023
	21st to end	Day	20% 4 10% 27% 26% 13%	4179
September	1st to 10th	Day	23% 2 8% 29% 28% 11%	2280
	11th to 20th	Day	24% 2 9% 32% 25% 8%	2138
	21st to end	Day	24% 2 8% 33% 28% 4	2090
October	1st to 10th	Day	20% 2 9% 21% 32% 16%	3480
	11th to 20th	Day	27% 2 11% 36% 20% 3	2976
	21st to end	Day	36% 3 11% 30% 15% 4	3091
November	1st to 10th	Day	30% 4 13% 27% 21% 5%	1763
	11th to 20th	Day	32% 3 10% 29% 22% 5%	1800
	21st to end	Day	32% 3 15% 32% 15% 4	1714
December	1st to 10th	Day	36% 3 15% 29% 15% 2	2620
	11th to 20th	Day	31% 4 19% 32% 13% 1	3024
	21st to end	Day	41% 2 8% 38% 11% 1	4004
January	1st to 10th	Night	49% 2 11% 27% 11% 1	6327
	11th to 20th	Night	43% 3 14% 23% 16% 1	6340
	21st to end	Night	31% 2 15% 32% 19% 1	6974
February	1st to 10th	Night	47% 3 13% 22% 13% 1	2643
	11th to 20th	Night	43% 4 12% 25% 14% 3	2338
	21st to end	Night	36% 3 14% 28% 15% 4	1980
March	1st to 10th	Night	37% 2 7% 28% 22% 3	5374
	11th to 20th	Night	29% 2 13% 33% 21% 2	5258
	21st to end	Night	49% 3 16% 22% 9% 1	5102
April	1st to 10th	Night	42% 5% 12% 25% 14% 3	2000
	11th to 20th	Night	41% 3 12% 22% 19% 3	1963
	21st to end	Night	41% 3 14% 28% 13% 1	1800
May	1st to 10th	Night	43% 4 10% 26% 15% 3	2940
	11th to 20th	Night	29% 3 14% 38% 14% 1	2677
	21st to end	Night	42% 3 13% 28% 13% 1	2806
June	1st to 10th	Night	29% 4 19% 29% 17% 2	1520
	11th to 20th	Night	32% 4 20% 25% 16% 3	1520
	21st to end	Night	26% 4 13% 32% 20% 5%	1520
July	1st to 10th	Night	25% 4 18% 23% 25% 4	2500
	11th to 20th	Night	20% 4 14% 32% 22% 8%	2492
	21st to end	Night	21% 4 14% 28% 26% 8%	2674
August	1st to 10th	Night	30% 6% 16% 23% 20% 6%	2611
	11th to 20th	Night	31% 5% 17% 23% 20% 4	2879
	21st to end	Night	25% 5% 13% 23% 26% 9%	3487
September	1st to 10th	Night	23% 2 8% 29% 29% 9%	1900
	11th to 20th	Night	23% 4 11% 29% 27% 7%	2042
	21st to end	Night	26% 3 6% 31% 27% 7%	2090
October	1st to 10th	Night	21% 2 6% 20% 32% 19%	3480
	11th to 20th	Night	25% 4 10% 36% 22% 4	3917
	21st to end	Night	32% 3 12% 27% 20% 6%	4467
November	1st to 10th	Night	34% 2 12% 27% 19% 6%	2535
	11th to 20th	Night	35% 2 10% 27% 21% 5%	2600
	21st to end	Night	30% 4 14% 30% 18% 3	2685
December	1st to 10th	Night	32% 4 18% 29% 16% 1	4570
	11th to 20th	Night	35% 4 16% 32% 12% 2	5182
	21st to end	Night	43% 3 9% 32% 12% 1	6974

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	8% 5% 30% 32% 19% 5%	300
	11th to 20th	Day	12% 8% 34% 29% 15% 2	300
	21st to end	Day	10% 10% 41% 27% 10% 2	330
February	1st to 10th	Day	13% 9% 37% 34% 6%	300
	11th to 20th	Day	12% 9% 40% 29% 9%	300
	21st to end	Day	14% 9% 42% 26% 8% 1	249
March	1st to 10th	Day	15% 6% 34% 30% 12% 4	300
	11th to 20th	Day	10% 8% 34% 31% 13% 4	300
	21st to end	Day	20% 11% 26% 26% 14% 3	490
April	1st to 10th	Day	19% 12% 32% 27% 9% 1	500
	11th to 20th	Day	21% 12% 30% 26% 10%	505
	21st to end	Day	19% 8% 26% 30% 16% 1	700
May	1st to 10th	Day	17% 8% 24% 30% 17% 4	703
	11th to 20th	Day	21% 4 19% 32% 17% 6%	725
	21st to end	Day	19% 5% 27% 30% 14% 4	760
June	1st to 10th	Day	7% 6% 22% 32% 22% 10%	680
	11th to 20th	Day	11% 6% 28% 34% 16% 4	680
	21st to end	Day	7% 5% 24% 34% 25% 4	680
July	1st to 10th	Day	7% 2 20% 39% 27% 6%	671
	11th to 20th	Day	6% 2 23% 43% 22% 4	668
	21st to end	Day	4 2 18% 41% 29% 5%	739
August	1st to 10th	Day	6% 2 20% 39% 27% 6%	676
	11th to 20th	Day	7% 3 21% 37% 25% 8%	634
	21st to end	Day	8% 5% 19% 34% 24% 10%	539
September	1st to 10th	Day	7% 4 23% 34% 24% 7%	490
	11th to 20th	Day	8% 2 20% 32% 27% 11%	348
	21st to end	Day	15% 7% 23% 30% 19% 7%	300
October	1st to 10th	Day	17% 7% 20% 26% 21% 10%	300
	11th to 20th	Day	14% 9% 32% 24% 16% 4	300
	21st to end	Day	17% 9% 32% 25% 15% 2	330
November	1st to 10th	Day	11% 10% 35% 30% 11% 4	300
	11th to 20th	Day	14% 11% 32% 29% 12% 2	300
	21st to end	Day	11% 7% 33% 32% 14% 2	300
December	1st to 10th	Day	14% 10% 35% 32% 9% 1	300
	11th to 20th	Day	10% 7% 41% 31% 10% 1	300
	21st to end	Day	15% 9% 33% 28% 12% 2	330
January	1st to 10th	Night	8% 9% 35% 35% 12% 2	1000
	11th to 20th	Night	9% 11% 36% 34% 9% 1	1000
	21st to end	Night	11% 8% 37% 36% 8%	1100
February	1st to 10th	Night	15% 9% 36% 33% 6%	900
	11th to 20th	Night	10% 6% 41% 36% 7%	784
	21st to end	Night	11% 6% 40% 35% 8% 1	660
March	1st to 10th	Night	14% 8% 33% 37% 9% 1	800
	11th to 20th	Night	12% 7% 31% 37% 12% 1	722
	21st to end	Night	18% 8% 31% 34% 9% 1	660
April	1st to 10th	Night	17% 7% 33% 36% 7% 1	600
	11th to 20th	Night	18% 9% 34% 35% 4	593
	21st to end	Night	18% 8% 28% 36% 10%	600
May	1st to 10th	Night	15% 5% 27% 39% 14% 1	600
	11th to 20th	Night	17% 5% 27% 38% 13% 1	591
	21st to end	Night	17% 6% 35% 31% 10% 1	634
June	1st to 10th	Night	10% 6% 28% 39% 16% 1	570
	11th to 20th	Night	12% 5% 34% 40% 9% 1	570
	21st to end	Night	6% 3 30% 45% 15%	570
July	1st to 10th	Night	8% 3 24% 45% 19% 1	555
	11th to 20th	Night	5% 1 29% 49% 15%	552
	21st to end	Night	5% 1 25% 54% 15% 1	624
August	1st to 10th	Night	6% 4 22% 50% 18%	567
	11th to 20th	Night	5% 2 24% 51% 17%	564
	21st to end	Night	4 4 24% 50% 18%	627
September	1st to 10th	Night	9% 1 26% 46% 17% 1	570
	11th to 20th	Night	9% 4 27% 42% 18% 1	570
	21st to end	Night	12% 5% 26% 41% 15% 1	570
October	1st to 10th	Night	16% 5% 26% 38% 14% 1	570
	11th to 20th	Night	13% 6% 30% 37% 13% 1	835
	21st to end	Night	14% 7% 30% 36% 12% 1	1045
November	1st to 10th	Night	10% 4 35% 40% 10% 1	975
	11th to 20th	Night	11% 8% 34% 37% 11%	1000
	21st to end	Night	9% 7% 36% 38% 10%	1000
December	1st to 10th	Night	12% 8% 38% 33% 9%	1000
	11th to 20th	Night	8% 7% 37% 37% 11% 1	1000
	21st to end	Night	15% 9% 32% 35% 9%	1100

Page generated at 2025-05-23 07:21:01. Version ac07

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