Pickett CCC Memorial State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pickett CCC Memorial State Park clear sky chart from 2005-11-06 to 2025-02-25.

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	13% 9% 3 7% 5% 4 5% 4 6% 7% 37%	109008
	Night	13% 9% 3 7% 5% 4 4 3 5% 7% 39%	109699
Transparency	Day	44% 6% 11% 22% 15% 2	112765
	Night	42% 6% 11% 22% 16% 3	114080
Seeing	Day	19% 13% 24% 22% 15% 6%	15057
	Night	18% 11% 24% 28% 17% 3	25189

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	14% 12% 8% 14% 4 4 5% 3 5% 5% 26%	4056
	11th to 20th	Day	14% 11% 6% 14% 4 3 3 2 3 4 34%	4060
	21st to end	Day	18% 12% 5% 6% 4 3 4 3 4 7% 34%	4527
February	1st to 10th	Day	15% 13% 4 9% 5% 5% 4 3 5% 6% 31%	2000
	11th to 20th	Day	21% 11% 5% 9% 5% 4 3 3 4 5% 31%	1948
	21st to end	Day	19% 12% 4 8% 4 4 3 3 4 4 34%	1610
March	1st to 10th	Day	20% 14% 4 7% 4 3 4 3 5% 5% 29%	3142
	11th to 20th	Day	14% 8% 3 6% 4 4 4 3 4 5% 46%	3480
	21st to end	Day	14% 10% 2 7% 4 4 4 3 5% 6% 38%	3815
April	1st to 10th	Day	12% 9% 3 6% 5% 4 3 3 7% 7% 40%	2234
	11th to 20th	Day	14% 9% 3 5% 4 4 5% 4 5% 6% 41%	2254
	21st to end	Day	14% 8% 3 6% 5% 5% 4 4 6% 7% 37%	2453
May	1st to 10th	Day	18% 10% 3 8% 5% 5% 5% 4 6% 7% 32%	4082
	11th to 20th	Day	17% 9% 3 7% 5% 5% 4 3 5% 6% 34%	4081
	21st to end	Day	11% 7% 3 7% 6% 5% 5% 5% 6% 8% 37%	4476
June	1st to 10th	Day	11% 6% 3 6% 6% 6% 6% 4 7% 9% 36%	2470
	11th to 20th	Day	6% 5% 2 5% 5% 6% 6% 5% 8% 10% 41%	2470
	21st to end	Day	7% 5% 2 6% 5% 6% 6% 6% 9% 11% 38%	2470
July	1st to 10th	Day	7% 4 2 8% 6% 6% 7% 6% 8% 10% 35%	4120
	11th to 20th	Day	9% 6% 2 7% 6% 6% 5% 5% 7% 9% 36%	4120
	21st to end	Day	18% 11% 4 10% 6% 6% 6% 5% 6% 8% 20%	4466
August	1st to 10th	Day	7% 5% 2 6% 5% 6% 5% 5% 8% 10% 41%	4104
	11th to 20th	Day	8% 5% 3 7% 5% 5% 6% 6% 8% 12% 35%	3865
	21st to end	Day	6% 4 2 5% 4 5% 5% 4 6% 8% 50%	4180
September	1st to 10th	Day	14% 7% 3 6% 5% 4 5% 4 5% 7% 40%	2153
	11th to 20th	Day	13% 7% 2 7% 5% 5% 5% 4 6% 8% 39%	2090
	21st to end	Day	16% 5% 2 5% 4 4 4 4 6% 6% 45%	2090
October	1st to 10th	Day	10% 5% 2 5% 3 3 3 3 6% 7% 52%	2090
	11th to 20th	Day	12% 6% 2 5% 4 3 4 3 6% 5% 51%	1981
	21st to end	Day	16% 7% 2 5% 3 2 4 3 6% 7% 45%	1990
November	1st to 10th	Day	11% 7% 2 5% 3 3 3 3 5% 6% 52%	1762
	11th to 20th	Day	14% 9% 2 5% 3 4 4 2 5% 7% 44%	1800
	21st to end	Day	15% 11% 3 6% 4 4 4 4 5% 6% 40%	1800
December	1st to 10th	Day	15% 10% 3 8% 4 3 4 3 4 5% 40%	2930
	11th to 20th	Day	18% 16% 6% 9% 4 4 4 3 4 5% 25%	3373
	21st to end	Day	15% 14% 6% 9% 5% 4 5% 4 6% 7% 25%	4466
January	1st to 10th	Night	14% 14% 6% 13% 5% 4 3 3 4 5% 30%	5889
	11th to 20th	Night	17% 12% 4 8% 6% 5% 3 2 3 4 35%	5900
	21st to end	Night	15% 13% 3 7% 4 4 4 3 4 4 39%	6426
February	1st to 10th	Night	17% 10% 4 9% 5% 5% 4 4 5% 6% 30%	2400
	11th to 20th	Night	22% 10% 4 9% 4 4 3 3 5% 4 31%	2338
	21st to end	Night	20% 13% 4 8% 5% 4 3 2 4 6% 30%	1939
March	1st to 10th	Night	20% 14% 3 7% 4 4 4 4 4 6% 29%	3711
	11th to 20th	Night	12% 8% 2 5% 4 4 3 4 5% 6% 46%	3480
	21st to end	Night	13% 9% 3 8% 4 5% 5% 4 5% 6% 39%	3817
April	1st to 10th	Night	11% 8% 3 6% 4 4 4 4 6% 6% 44%	1961
	11th to 20th	Night	14% 8% 3 6% 4 4 3 4 5% 6% 45%	1875
	21st to end	Night	12% 8% 3 7% 5% 4 4 3 5% 7% 42%	1725
May	1st to 10th	Night	13% 8% 3 8% 5% 5% 5% 4 7% 7% 34%	2813
	11th to 20th	Night	14% 10% 3 7% 5% 5% 4 4 6% 8% 36%	2812
	21st to end	Night	6% 5% 2 7% 6% 4 5% 4 7% 10% 44%	3079
June	1st to 10th	Night	8% 6% 2 6% 5% 5% 5% 5% 7% 9% 42%	1710
	11th to 20th	Night	4 3 1 6% 4 4 5% 4 8% 11% 50%	1710
	21st to end	Night	6% 5% 2 5% 5% 5% 6% 5% 7% 11% 42%	1710
July	1st to 10th	Night	6% 4 2 6% 4 6% 6% 5% 8% 11% 40%	2840
	11th to 20th	Night	9% 4 2 5% 4 4 5% 4 6% 10% 48%	2840
	21st to end	Night	12% 10% 4 10% 6% 7% 6% 5% 6% 9% 25%	3087
August	1st to 10th	Night	6% 4 3 5% 5% 4 4 4 7% 10% 48%	2825
	11th to 20th	Night	6% 5% 2 7% 5% 5% 4 4 6% 10% 45%	2960
	21st to end	Night	5% 3 1 3 2 3 4 3 5% 9% 61%	3476
September	1st to 10th	Night	10% 6% 3 6% 4 4 4 4 6% 7% 46%	2006
	11th to 20th	Night	12% 6% 2 7% 4 4 5% 3 6% 7% 46%	2090
	21st to end	Night	12% 5% 3 6% 4 3 3 4 5% 7% 50%	2090
October	1st to 10th	Night	10% 4 2 4 2 3 3 2 4 6% 58%	2090
	11th to 20th	Night	15% 5% 1 5% 3 4 3 2 4 6% 51%	2197
	21st to end	Night	13% 8% 2 6% 4 3 3 2 4 7% 48%	2605
November	1st to 10th	Night	10% 7% 2 6% 4 4 3 3 4 6% 50%	2536
	11th to 20th	Night	13% 9% 2 5% 4 3 3 3 5% 7% 45%	2600
	21st to end	Night	14% 11% 3 7% 4 3 3 2 4 6% 43%	2600
December	1st to 10th	Night	13% 14% 4 11% 5% 5% 3 2 4 4 36%	4250
	11th to 20th	Night	20% 14% 5% 10% 3 3 3 2 4 4 32%	4822
	21st to end	Night	13% 13% 6% 9% 6% 6% 6% 4 6% 7% 24%	6490

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	59% 5% 8% 17% 10% 1	4057
	11th to 20th	Day	54% 4 5% 16% 19% 2	4060
	21st to end	Day	50% 3 8% 23% 14% 2	4527
February	1st to 10th	Day	55% 5% 7% 17% 15% 2	2000
	11th to 20th	Day	57% 4 7% 17% 12% 2	1958
	21st to end	Day	53% 4 9% 16% 14% 5%	1610
March	1st to 10th	Day	54% 5% 7% 16% 12% 5%	3142
	11th to 20th	Day	40% 5% 9% 25% 17% 4	3480
	21st to end	Day	45% 6% 9% 26% 13% 1	3815
April	1st to 10th	Day	41% 6% 11% 23% 15% 3	2234
	11th to 20th	Day	43% 5% 7% 20% 22% 3	2254
	21st to end	Day	44% 7% 11% 25% 12% 2	2453
May	1st to 10th	Day	50% 8% 11% 22% 9% 1	4120
	11th to 20th	Day	49% 7% 10% 22% 11%	4085
	21st to end	Day	41% 9% 12% 20% 16% 2	4489
June	1st to 10th	Day	42% 8% 12% 22% 14% 2	2470
	11th to 20th	Day	33% 11% 17% 21% 16% 2	2470
	21st to end	Day	36% 10% 17% 20% 14% 4	2470
July	1st to 10th	Day	37% 11% 21% 20% 9% 1	4055
	11th to 20th	Day	39% 9% 16% 27% 7% 2	4051
	21st to end	Day	60% 8% 11% 14% 6% 1	4324
August	1st to 10th	Day	33% 10% 18% 27% 13%	4091
	11th to 20th	Day	35% 10% 18% 24% 13% 1	3904
	21st to end	Day	28% 8% 14% 37% 12% 2	4179
September	1st to 10th	Day	43% 7% 11% 18% 18% 4	2153
	11th to 20th	Day	42% 7% 10% 21% 18% 2	2090
	21st to end	Day	38% 6% 10% 23% 19% 4	2090
October	1st to 10th	Day	24% 5% 7% 21% 38% 5%	3480
	11th to 20th	Day	24% 3 10% 23% 31% 9%	3273
	21st to end	Day	30% 4 9% 27% 20% 10%	3253
November	1st to 10th	Day	34% 3 9% 23% 26% 4	1762
	11th to 20th	Day	40% 4 7% 22% 22% 5%	1800
	21st to end	Day	45% 4 8% 20% 20% 3	1800
December	1st to 10th	Day	45% 5% 7% 20% 23% 1	2930
	11th to 20th	Day	61% 4 7% 17% 10% 2	3370
	21st to end	Day	55% 6% 12% 18% 8% 1	4466
January	1st to 10th	Night	55% 6% 8% 18% 11% 1	5889
	11th to 20th	Night	53% 4 5% 15% 17% 5%	5900
	21st to end	Night	49% 4 7% 17% 20% 3	6426
February	1st to 10th	Night	53% 5% 10% 18% 13% 1	2400
	11th to 20th	Night	56% 3 7% 17% 13% 4	2339
	21st to end	Night	56% 4 7% 15% 16% 3	1939
March	1st to 10th	Night	55% 6% 9% 14% 14% 3	3711
	11th to 20th	Night	37% 5% 9% 28% 13% 9%	3480
	21st to end	Night	45% 5% 11% 24% 14% 1	3817
April	1st to 10th	Night	38% 6% 10% 25% 18% 3	1961
	11th to 20th	Night	39% 4 10% 19% 22% 5%	1875
	21st to end	Night	41% 7% 10% 27% 13% 1	1725
May	1st to 10th	Night	45% 10% 12% 23% 8% 1	2840
	11th to 20th	Night	45% 8% 14% 23% 10%	2813
	21st to end	Night	31% 10% 16% 25% 17% 1	3087
June	1st to 10th	Night	35% 8% 14% 25% 15% 2	1710
	11th to 20th	Night	25% 9% 20% 27% 17% 2	1710
	21st to end	Night	33% 9% 18% 23% 14% 4	1710
July	1st to 10th	Night	32% 12% 21% 24% 10% 1	2795
	11th to 20th	Night	30% 7% 18% 32% 10% 2	2786
	21st to end	Night	54% 9% 13% 16% 7% 1	2988
August	1st to 10th	Night	28% 9% 15% 32% 15% 1	2814
	11th to 20th	Night	32% 8% 19% 28% 12% 1	2987
	21st to end	Night	19% 7% 13% 41% 18% 2	3476
September	1st to 10th	Night	35% 9% 12% 19% 19% 6%	2006
	11th to 20th	Night	37% 7% 9% 24% 20% 2	2090
	21st to end	Night	34% 6% 10% 22% 24% 4	2090
October	1st to 10th	Night	22% 5% 9% 23% 33% 8%	3480
	11th to 20th	Night	23% 3 7% 26% 27% 14%	3644
	21st to end	Night	24% 4 9% 24% 26% 12%	4292
November	1st to 10th	Night	36% 4 7% 22% 24% 7%	2536
	11th to 20th	Night	39% 5% 7% 20% 23% 6%	2600
	21st to end	Night	45% 3 7% 24% 19% 3	2600
December	1st to 10th	Night	52% 4 7% 17% 19% 1	4250
	11th to 20th	Night	55% 4 7% 19% 13% 2	4824
	21st to end	Night	55% 8% 11% 17% 9%	6490

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	29% 26% 31% 11% 2 1	300
	11th to 20th	Day	36% 31% 21% 10% 2	300
	21st to end	Day	25% 32% 33% 9% 1	330
February	1st to 10th	Day	27% 28% 29% 13% 2	300
	11th to 20th	Day	40% 27% 26% 6% 1	300
	21st to end	Day	40% 24% 31% 5% 1	237
March	1st to 10th	Day	30% 23% 35% 8% 4	279
	11th to 20th	Day	27% 24% 30% 15% 4 1	460
	21st to end	Day	29% 18% 31% 15% 6% 1	506
April	1st to 10th	Day	27% 19% 25% 18% 10% 1	460
	11th to 20th	Day	22% 19% 29% 19% 10% 2	452
	21st to end	Day	22% 18% 30% 18% 11% 2	460
May	1st to 10th	Day	21% 14% 34% 17% 10% 3	463
	11th to 20th	Day	17% 11% 26% 25% 13% 7%	487
	21st to end	Day	15% 8% 22% 28% 18% 9%	529
June	1st to 10th	Day	12% 9% 20% 30% 19% 10%	490
	11th to 20th	Day	7% 4 20% 32% 26% 11%	490
	21st to end	Day	8% 5% 25% 29% 22% 9%	490
July	1st to 10th	Day	11% 5% 15% 26% 26% 18%	485
	11th to 20th	Day	9% 6% 14% 29% 28% 14%	484
	21st to end	Day	14% 4 14% 30% 26% 12%	532
August	1st to 10th	Day	14% 3 16% 28% 28% 12%	486
	11th to 20th	Day	11% 4 19% 36% 22% 9%	479
	21st to end	Day	12% 4 10% 27% 29% 19%	539
September	1st to 10th	Day	14% 3 14% 27% 28% 13%	490
	11th to 20th	Day	14% 5% 14% 28% 28% 12%	490
	21st to end	Day	18% 6% 20% 28% 19% 9%	490
October	1st to 10th	Day	11% 7% 21% 31% 24% 5%	490
	11th to 20th	Day	16% 15% 25% 26% 14% 4	490
	21st to end	Day	24% 10% 29% 27% 9% 2	439
November	1st to 10th	Day	18% 14% 37% 22% 6% 3	300
	11th to 20th	Day	21% 18% 40% 17% 3	300
	21st to end	Day	21% 21% 35% 14% 9%	300
December	1st to 10th	Day	30% 21% 34% 12% 3	300
	11th to 20th	Day	30% 19% 30% 15% 4 1	300
	21st to end	Day	31% 21% 33% 12% 3	330
January	1st to 10th	Night	24% 22% 29% 22% 4	800
	11th to 20th	Night	30% 21% 27% 18% 4	800
	21st to end	Night	21% 19% 37% 21% 2	880
February	1st to 10th	Night	26% 16% 33% 22% 3	800
	11th to 20th	Night	29% 19% 34% 17% 1	783
	21st to end	Night	31% 19% 32% 17% 1	647
March	1st to 10th	Night	24% 14% 33% 25% 4	760
	11th to 20th	Night	24% 16% 31% 22% 6% 1	760
	21st to end	Night	22% 15% 31% 25% 8%	836
April	1st to 10th	Night	17% 15% 30% 27% 10%	631
	11th to 20th	Night	18% 13% 33% 24% 12%	563
	21st to end	Night	16% 9% 34% 31% 9% 1	570
May	1st to 10th	Night	15% 8% 29% 30% 16% 3	570
	11th to 20th	Night	13% 7% 22% 33% 20% 4	561
	21st to end	Night	7% 3 22% 33% 29% 6%	617
June	1st to 10th	Night	10% 4 16% 38% 27% 6%	570
	11th to 20th	Night	4 2 15% 42% 30% 7%	570
	21st to end	Night	6% 3 16% 41% 29% 5%	570
July	1st to 10th	Night	10% 2 9% 31% 40% 8%	555
	11th to 20th	Night	8% 2 10% 30% 42% 7%	552
	21st to end	Night	8% 3 8% 35% 39% 7%	624
August	1st to 10th	Night	10% 3 8% 31% 41% 7%	567
	11th to 20th	Night	10% 2 9% 39% 34% 6%	564
	21st to end	Night	9% 2 7% 33% 40% 9%	627
September	1st to 10th	Night	12% 3 9% 28% 41% 7%	676
	11th to 20th	Night	13% 3 12% 31% 35% 6%	760
	21st to end	Night	14% 3 17% 33% 28% 5%	760
October	1st to 10th	Night	13% 5% 17% 32% 27% 7%	760
	11th to 20th	Night	18% 9% 22% 32% 18% 2	760
	21st to end	Night	17% 10% 28% 29% 15% 2	836
November	1st to 10th	Night	14% 10% 23% 34% 16% 2	780
	11th to 20th	Night	18% 14% 29% 28% 10% 1	800
	21st to end	Night	21% 15% 29% 27% 9%	800
December	1st to 10th	Night	27% 17% 27% 24% 6%	800
	11th to 20th	Night	23% 17% 27% 26% 6% 1	800
	21st to end	Night	27% 17% 27% 25% 4	880

Page generated at 2025-02-22 05:51:38. Version ac07

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