Possum Kingdom State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Possum Kingdom State Park clear sky chart from 2005-11-06 to 2026-01-17.

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% 5% 2 4 3 3 3 3 5% 6% 57%	127364
	Night	8% 4 1 4 3 3 3 3 4 7% 60%	124629
Transparency	Day	27% 4 9% 23% 26% 11%	131133
	Night	25% 4 8% 22% 27% 14%	128923
Seeing	Day	10% 7% 24% 30% 21% 7%	16698
	Night	10% 8% 31% 36% 14% 1	26686

By Month

Percentage Cloud Cover SE (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	10% 8% 2 6% 3 3 3 2 4 5% 55%	4167
	11th to 20th	Day	6% 4 1 3 2 2 2 2 4 6% 67%	4134
	21st to end	Day	17% 8% 2 5% 2 2 2 2 4 4 52%	4644
February	1st to 10th	Day	12% 6% 2 5% 3 3 3 3 4 5% 55%	2000
	11th to 20th	Day	12% 8% 2 5% 3 3 3 3 3 4 53%	1949
	21st to end	Day	15% 6% 2 4 2 2 3 2 3 4 57%	1650
March	1st to 10th	Day	12% 5% 2 4 3 3 3 3 4 6% 55%	4756
	11th to 20th	Day	10% 4 2 4 3 3 3 2 4 5% 61%	4980
	21st to end	Day	6% 5% 2 4 4 4 4 4 6% 6% 55%	5462
April	1st to 10th	Day	9% 5% 2 4 3 3 4 4 4 6% 57%	2200
	11th to 20th	Day	10% 5% 2 5% 5% 3 3 3 4 5% 55%	2307
	21st to end	Day	9% 4 2 6% 4 4 3 3 5% 5% 56%	2585
May	1st to 10th	Day	12% 6% 2 6% 4 4 3 3 5% 7% 48%	5862
	11th to 20th	Day	11% 6% 2 6% 3 3 4 3 5% 5% 51%	5862
	21st to end	Day	10% 6% 2 7% 4 4 5% 3 6% 8% 45%	6434
June	1st to 10th	Day	6% 3 1 4 3 4 5% 4 5% 9% 55%	2600
	11th to 20th	Day	4 2 1 3 3 4 5% 4 6% 9% 60%	2600
	21st to end	Day	5% 3 1 3 3 4 3 3 5% 9% 62%	2600
July	1st to 10th	Day	11% 6% 2 7% 5% 4 5% 4 5% 7% 44%	5900
	11th to 20th	Day	3 3 1 4 3 3 4 3 6% 8% 61%	5900
	21st to end	Day	2 2 1 3 3 3 4 3 6% 9% 65%	6422
August	1st to 10th	Day	2 1 1 3 2 3 3 3 5% 8% 70%	4234
	11th to 20th	Day	3 2 1 3 3 3 3 4 5% 9% 64%	3955
	21st to end	Day	3 2 1 3 3 4 4 4 6% 8% 62%	4252
September	1st to 10th	Day	11% 4 2 4 3 4 4 3 4 6% 57%	2200
	11th to 20th	Day	10% 5% 1 5% 4 5% 4 4 5% 7% 51%	2200
	21st to end	Day	8% 2 1 4 3 3 4 4 5% 6% 60%	2200
October	1st to 10th	Day	4 3 1 4 3 2 3 3 5% 6% 66%	2200
	11th to 20th	Day	8% 4 1 3 2 2 3 2 3 5% 68%	2057
	21st to end	Day	12% 4 1 4 2 2 2 2 3 4 65%	2200
November	1st to 10th	Day	8% 5% 1 4 3 2 3 3 3 6% 63%	1974
	11th to 20th	Day	6% 3 1 3 2 3 3 3 5% 6% 66%	1890
	21st to end	Day	12% 4 1 4 4 3 3 3 4 6% 56%	1890
December	1st to 10th	Day	11% 6% 2 5% 3 3 3 3 5% 6% 52%	3030
	11th to 20th	Day	8% 5% 2 5% 4 4 4 3 4 5% 56%	3481
	21st to end	Day	11% 7% 2 5% 3 3 2 2 3 4 59%	4587
January	1st to 10th	Night	12% 5% 2 4 3 2 3 3 4 6% 58%	6018
	11th to 20th	Night	6% 3 1 3 2 2 2 2 3 5% 71%	5979
	21st to end	Night	16% 8% 2 4 3 3 3 3 4 5% 50%	6376
February	1st to 10th	Night	10% 6% 1 5% 3 3 3 3 4 6% 56%	2400
	11th to 20th	Night	12% 6% 1 5% 3 3 3 3 4 6% 54%	2338
	21st to end	Night	12% 5% 2 4 3 2 3 2 4 5% 59%	1980
March	1st to 10th	Night	10% 7% 1 4 3 3 3 3 4 6% 56%	5103
	11th to 20th	Night	10% 4 1 3 2 2 3 3 4 7% 61%	4980
	21st to end	Night	6% 5% 2 5% 4 3 4 3 4 5% 58%	5467
April	1st to 10th	Night	7% 5% 2 4 3 3 3 3 5% 6% 58%	2200
	11th to 20th	Night	10% 4 2 4 3 3 3 3 5% 6% 56%	2038
	21st to end	Night	9% 3 1 3 3 3 3 3 5% 7% 58%	1812
May	1st to 10th	Night	12% 6% 2 6% 4 4 4 3 5% 5% 49%	4053
	11th to 20th	Night	7% 5% 2 5% 4 4 4 4 5% 7% 53%	4053
	21st to end	Night	9% 5% 2 6% 4 3 4 4 6% 8% 51%	4443
June	1st to 10th	Night	3 2 1 4 3 3 3 4 7% 11% 58%	1800
	11th to 20th	Night	2 2 1 3 3 3 3 3 6% 9% 65%	1800
	21st to end	Night	3 3 1 4 3 3 3 3 4 7% 67%	1800
July	1st to 10th	Night	7% 5% 2 7% 4 4 4 3 5% 9% 47%	4078
	11th to 20th	Night	2 2 1 3 2 2 3 3 5% 9% 70%	4077
	21st to end	Night	1 1 1 3 2 2 3 3 5% 9% 69%	4449
August	1st to 10th	Night	1 1 1 2 2 1 3 2 5% 8% 75%	2926
	11th to 20th	Night	3 2 1 3 2 2 2 3 5% 9% 69%	3086
	21st to end	Night	2 2 1 4 2 3 4 3 5% 9% 65%	3653
September	1st to 10th	Night	8% 3 2 3 3 3 3 3 5% 8% 58%	2200
	11th to 20th	Night	9% 5% 2 6% 5% 4 3 3 5% 7% 52%	2200
	21st to end	Night	8% 1 1 3 2 3 4 3 5% 6% 64%	2200
October	1st to 10th	Night	5% 2 1 3 3 2 3 3 5% 7% 67%	2200
	11th to 20th	Night	8% 3 1 4 2 2 2 2 3 5% 69%	2321
	21st to end	Night	10% 4 1 3 2 2 2 2 3 5% 66%	2640
November	1st to 10th	Night	8% 3 2 4 3 3 3 2 3 5% 65%	2540
	11th to 20th	Night	4 3 1 3 3 3 3 2 3 7% 67%	2730
	21st to end	Night	13% 5% 1 4 3 3 3 3 4 6% 56%	2730
December	1st to 10th	Night	11% 6% 2 5% 3 3 3 2 4 6% 55%	4380
	11th to 20th	Night	9% 5% 2 4 3 3 3 3 4 6% 57%	4946
	21st to end	Night	10% 5% 2 5% 3 3 3 2 4 4 59%	6633

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	33% 3 6% 23% 27% 8%	4168
	11th to 20th	Day	19% 2 6% 23% 38% 11%	4134
	21st to end	Day	38% 2 4 17% 22% 17%	4644
February	1st to 10th	Day	31% 3 6% 18% 26% 14%	2000
	11th to 20th	Day	36% 3 8% 18% 23% 11%	1959
	21st to end	Day	33% 2 4 13% 27% 20%	1650
March	1st to 10th	Day	30% 3 6% 12% 24% 25%	4756
	11th to 20th	Day	27% 4 9% 14% 22% 25%	4980
	21st to end	Day	28% 5% 10% 22% 24% 11%	5464
April	1st to 10th	Day	30% 5% 10% 20% 22% 14%	2200
	11th to 20th	Day	32% 4 7% 18% 23% 15%	2307
	21st to end	Day	31% 5% 8% 20% 29% 8%	2585
May	1st to 10th	Day	35% 6% 9% 22% 19% 9%	5900
	11th to 20th	Day	35% 5% 8% 17% 28% 7%	5866
	21st to end	Day	36% 7% 11% 24% 13% 8%	6447
June	1st to 10th	Day	24% 8% 15% 29% 20% 4	2600
	11th to 20th	Day	20% 6% 14% 29% 24% 6%	2600
	21st to end	Day	21% 5% 14% 26% 26% 8%	2600
July	1st to 10th	Day	39% 6% 11% 28% 14% 2	5836
	11th to 20th	Day	21% 5% 15% 31% 26% 4	5831
	21st to end	Day	16% 6% 13% 35% 28% 2	6240
August	1st to 10th	Day	13% 5% 10% 26% 37% 8%	4220
	11th to 20th	Day	17% 6% 12% 34% 27% 4	3994
	21st to end	Day	19% 6% 17% 32% 23% 4	4251
September	1st to 10th	Day	29% 4 9% 20% 26% 10%	2200
	11th to 20th	Day	32% 5% 9% 21% 24% 8%	2200
	21st to end	Day	25% 4 8% 21% 26% 15%	2200
October	1st to 10th	Day	13% 3 6% 16% 36% 26%	3590
	11th to 20th	Day	17% 3 8% 19% 35% 18%	3323
	21st to end	Day	19% 2 4 26% 36% 13%	3538
November	1st to 10th	Day	25% 3 8% 22% 28% 14%	1974
	11th to 20th	Day	20% 4 8% 22% 31% 16%	1890
	21st to end	Day	31% 3 5% 21% 27% 13%	1890
December	1st to 10th	Day	34% 3 5% 25% 26% 7%	3030
	11th to 20th	Day	31% 3 7% 14% 29% 15%	3479
	21st to end	Day	32% 3 4 26% 24% 12%	4587
January	1st to 10th	Night	29% 3 7% 25% 28% 8%	6018
	11th to 20th	Night	18% 2 5% 20% 36% 19%	5979
	21st to end	Night	37% 4 5% 14% 25% 16%	6376
February	1st to 10th	Night	31% 3 7% 17% 25% 17%	2400
	11th to 20th	Night	33% 3 8% 15% 25% 15%	2338
	21st to end	Night	30% 3 6% 16% 22% 23%	1980
March	1st to 10th	Night	30% 3 5% 14% 24% 25%	5103
	11th to 20th	Night	24% 3 8% 19% 16% 30%	4980
	21st to end	Night	28% 5% 7% 19% 32% 10%	5467
April	1st to 10th	Night	27% 4 11% 20% 21% 18%	2200
	11th to 20th	Night	29% 5% 10% 17% 22% 17%	2038
	21st to end	Night	25% 5% 11% 23% 29% 8%	1812
May	1st to 10th	Night	36% 6% 8% 22% 19% 8%	4080
	11th to 20th	Night	30% 6% 9% 19% 25% 12%	4054
	21st to end	Night	31% 6% 13% 25% 16% 10%	4452
June	1st to 10th	Night	19% 6% 17% 34% 20% 5%	1800
	11th to 20th	Night	16% 6% 14% 31% 25% 8%	1800
	21st to end	Night	18% 5% 12% 26% 29% 10%	1800
July	1st to 10th	Night	34% 6% 12% 31% 16% 2	4035
	11th to 20th	Night	13% 4 11% 36% 29% 7%	4026
	21st to end	Night	13% 4 14% 36% 28% 4	4320
August	1st to 10th	Night	9% 3 8% 28% 43% 9%	2916
	11th to 20th	Night	14% 4 13% 35% 28% 7%	3113
	21st to end	Night	17% 5% 20% 30% 24% 4	3653
September	1st to 10th	Night	25% 5% 9% 23% 26% 12%	2200
	11th to 20th	Night	32% 6% 9% 20% 22% 11%	2200
	21st to end	Night	20% 4 8% 22% 27% 18%	2200
October	1st to 10th	Night	10% 2 6% 15% 33% 34%	3590
	11th to 20th	Night	14% 3 8% 18% 34% 23%	3781
	21st to end	Night	19% 2 4 22% 39% 14%	4252
November	1st to 10th	Night	24% 4 7% 20% 27% 19%	2540
	11th to 20th	Night	20% 3 7% 23% 30% 18%	2730
	21st to end	Night	31% 4 6% 17% 29% 14%	2730
December	1st to 10th	Night	32% 4 5% 22% 27% 11%	4380
	11th to 20th	Night	30% 4 5% 15% 30% 16%	4947
	21st to end	Night	30% 3 6% 21% 28% 13%	6633

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	15% 15% 39% 26% 5%	330
	11th to 20th	Day	15% 16% 32% 30% 5% 2	318
	21st to end	Day	15% 15% 39% 24% 6% 1	330
February	1st to 10th	Day	17% 15% 38% 24% 5%	300
	11th to 20th	Day	22% 15% 43% 14% 6%	300
	21st to end	Day	22% 14% 39% 21% 4	249
March	1st to 10th	Day	22% 15% 34% 25% 5%	300
	11th to 20th	Day	18% 17% 39% 21% 3 2	300
	21st to end	Day	13% 15% 46% 19% 7% 1	330
April	1st to 10th	Day	16% 17% 36% 20% 10% 1	300
	11th to 20th	Day	16% 18% 43% 18% 5%	425
	21st to end	Day	13% 17% 37% 26% 7% 1	685
May	1st to 10th	Day	13% 11% 38% 30% 8% 1	703
	11th to 20th	Day	13% 7% 36% 29% 11% 3	725
	21st to end	Day	10% 6% 35% 32% 15% 3	789
June	1st to 10th	Day	6% 4 16% 44% 24% 6%	730
	11th to 20th	Day	5% 2 18% 47% 23% 5%	730
	21st to end	Day	3 2 13% 36% 37% 10%	730
July	1st to 10th	Day	5% 2 8% 36% 36% 13%	721
	11th to 20th	Day	3 2 6% 33% 42% 14%	718
	21st to end	Day	2 1 7% 31% 41% 18%	794
August	1st to 10th	Day	2 1 4 33% 46% 14%	726
	11th to 20th	Day	5% 2 6% 34% 42% 12%	590
	21st to end	Day	5% 2 5% 32% 38% 19%	549
September	1st to 10th	Day	11% 1 7% 22% 38% 21%	330
	11th to 20th	Day	3 1 6% 28% 44% 18%	330
	21st to end	Day	12% 2 8% 33% 29% 16%	330
October	1st to 10th	Day	4 2 18% 35% 30% 10%	330
	11th to 20th	Day	8% 7% 29% 35% 18% 2	330
	21st to end	Day	21% 8% 25% 30% 15% 2	363
November	1st to 10th	Day	15% 6% 34% 29% 15% 2	330
	11th to 20th	Day	12% 9% 32% 32% 11% 5%	330
	21st to end	Day	18% 15% 35% 23% 8% 2	330
December	1st to 10th	Day	17% 12% 34% 26% 8% 2	330
	11th to 20th	Day	11% 10% 42% 30% 7% 1	330
	21st to end	Day	17% 15% 32% 27% 8%	363
January	1st to 10th	Night	12% 10% 37% 32% 9%	1050
	11th to 20th	Night	13% 13% 32% 34% 7%	1031
	21st to end	Night	13% 13% 36% 30% 7%	1051
February	1st to 10th	Night	13% 11% 40% 30% 5% 1	800
	11th to 20th	Night	16% 14% 37% 28% 4	784
	21st to end	Night	16% 13% 46% 24% 2	660
March	1st to 10th	Night	14% 13% 40% 28% 5%	685
	11th to 20th	Night	15% 12% 41% 27% 5%	600
	21st to end	Night	8% 14% 45% 29% 4	660
April	1st to 10th	Night	11% 13% 48% 26% 3	600
	11th to 20th	Night	11% 15% 47% 23% 4	593
	21st to end	Night	11% 12% 45% 27% 6%	600
May	1st to 10th	Night	11% 10% 45% 28% 5%	600
	11th to 20th	Night	9% 5% 41% 34% 11% 1	591
	21st to end	Night	8% 4 38% 37% 12% 1	650
June	1st to 10th	Night	4 2 26% 48% 19% 1	600
	11th to 20th	Night	2 1 29% 57% 12%	600
	21st to end	Night	4 2 19% 50% 24% 2	600
July	1st to 10th	Night	5% 1 11% 49% 31% 3	585
	11th to 20th	Night	3 1 10% 50% 35% 1	582
	21st to end	Night	2 1 9% 52% 35% 2	657
August	1st to 10th	Night	2 1 7% 53% 36% 2	597
	11th to 20th	Night	5% 1 10% 46% 36% 3	594
	21st to end	Night	3 1 6% 45% 40% 5%	660
September	1st to 10th	Night	9% 1 11% 42% 34% 4	600
	11th to 20th	Night	12% 1 11% 43% 32% 1	600
	21st to end	Night	8% 1 17% 42% 31% 2	600
October	1st to 10th	Night	5% 2 22% 46% 24% 1	600
	11th to 20th	Night	8% 6% 31% 40% 14% 1	721
	21st to end	Night	13% 8% 32% 34% 13% 1	880
November	1st to 10th	Night	10% 5% 32% 38% 13% 1	900
	11th to 20th	Night	6% 8% 37% 38% 11% 1	1050
	21st to end	Night	17% 9% 36% 28% 10% 1	1050
December	1st to 10th	Night	13% 9% 35% 36% 6%	1050
	11th to 20th	Night	14% 9% 36% 34% 7%	1050
	21st to end	Night	13% 10% 38% 32% 7%	1155

Page generated at 2026-01-14 00:14:31. Version ac07

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