Cumberland Mountain State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cumberland Mountain State Park clear sky chart from 2005-11-06 to 2024-12-02.

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% 8% 3 7% 5% 5% 5% 4 6% 7% 36%	101181
	Night	12% 8% 3 7% 4 4 4 4 5% 7% 40%	98424
Transparency	Day	43% 8% 11% 21% 15% 3	104950
	Night	40% 7% 10% 22% 17% 4	102780
Seeing	Day	18% 13% 25% 22% 15% 7%	14795
	Night	16% 11% 24% 28% 17% 3	24838

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% 7% 8% 5% 5% 5% 5% 5% 5% 29%	2836
	11th to 20th	Day	18% 9% 3 15% 5% 4 4 3 4 5% 31%	2840
	21st to end	Day	21% 11% 6% 7% 3 3 3 3 5% 5% 33%	3220
February	1st to 10th	Day	17% 12% 3 8% 5% 4 4 4 4 5% 33%	1900
	11th to 20th	Day	20% 11% 4 8% 5% 3 3 3 4 6% 32%	1848
	21st to end	Day	19% 10% 3 9% 5% 4 3 3 4 6% 33%	1570
March	1st to 10th	Day	21% 13% 5% 8% 4 4 3 3 5% 7% 27%	3135
	11th to 20th	Day	14% 9% 3 6% 4 3 4 2 4 5% 46%	3480
	21st to end	Day	15% 10% 3 7% 6% 4 4 4 6% 6% 37%	3815
April	1st to 10th	Day	12% 8% 3 6% 6% 4 4 4 6% 7% 41%	2244
	11th to 20th	Day	13% 10% 3 6% 4 4 4 3 5% 6% 42%	2254
	21st to end	Day	13% 7% 3 6% 5% 4 4 4 6% 7% 39%	2427
May	1st to 10th	Day	16% 9% 3 7% 5% 5% 4 4 6% 7% 34%	4082
	11th to 20th	Day	16% 9% 3 8% 5% 4 5% 4 5% 7% 33%	4081
	21st to end	Day	10% 7% 3 8% 5% 5% 5% 4 6% 8% 38%	4476
June	1st to 10th	Day	10% 6% 3 7% 5% 5% 6% 5% 7% 10% 35%	2470
	11th to 20th	Day	5% 4 2 7% 6% 7% 7% 5% 7% 10% 41%	2470
	21st to end	Day	7% 5% 2 6% 6% 6% 5% 6% 8% 12% 36%	2470
July	1st to 10th	Day	6% 5% 2 8% 7% 7% 7% 7% 9% 11% 32%	4120
	11th to 20th	Day	10% 7% 3 8% 7% 6% 7% 5% 7% 9% 31%	4120
	21st to end	Day	15% 12% 5% 11% 8% 7% 6% 5% 6% 7% 18%	4466
August	1st to 10th	Day	5% 5% 2 6% 5% 6% 7% 7% 9% 11% 38%	4104
	11th to 20th	Day	7% 5% 2 7% 6% 7% 7% 6% 8% 11% 34%	3796
	21st to end	Day	7% 5% 2 7% 5% 5% 6% 6% 8% 9% 42%	4180
September	1st to 10th	Day	13% 7% 3 7% 4 6% 6% 4 6% 7% 37%	2157
	11th to 20th	Day	14% 8% 2 7% 5% 4 5% 4 6% 7% 38%	2090
	21st to end	Day	15% 6% 2 6% 4 4 4 4 5% 6% 44%	2090
October	1st to 10th	Day	11% 5% 2 6% 3 4 4 3 5% 5% 52%	2090
	11th to 20th	Day	12% 6% 2 5% 4 3 3 3 4 5% 52%	2002
	21st to end	Day	14% 6% 2 5% 3 3 4 4 5% 6% 47%	1990
November	1st to 10th	Day	9% 7% 2 5% 3 3 5% 3 5% 6% 52%	1762
	11th to 20th	Day	11% 9% 2 6% 5% 4 4 3 4 6% 45%	1800
	21st to end	Day	14% 9% 2 7% 5% 4 3 3 5% 6% 42%	1800
December	1st to 10th	Day	18% 13% 5% 8% 3 4 4 3 4 5% 33%	1719
	11th to 20th	Day	13% 9% 4 8% 6% 5% 5% 4 5% 6% 33%	2153
	21st to end	Day	16% 11% 8% 7% 4 4 4 3 6% 8% 30%	3124
January	1st to 10th	Night	15% 13% 6% 9% 4 3 4 3 5% 6% 32%	4109
	11th to 20th	Night	17% 11% 4 8% 5% 5% 3 2 4 5% 35%	4120
	21st to end	Night	19% 14% 6% 7% 4 3 3 3 4 5% 33%	4432
February	1st to 10th	Night	15% 10% 4 9% 4 4 5% 3 5% 6% 35%	2280
	11th to 20th	Night	20% 10% 4 7% 5% 4 4 4 4 4 34%	2218
	21st to end	Night	21% 11% 4 7% 5% 4 4 3 5% 5% 31%	1884
March	1st to 10th	Night	21% 12% 4 8% 5% 4 4 3 5% 5% 29%	3716
	11th to 20th	Night	10% 8% 2 7% 4 4 5% 3 5% 6% 46%	3480
	21st to end	Night	14% 8% 3 8% 5% 5% 5% 4 4 6% 38%	3817
April	1st to 10th	Night	12% 6% 3 5% 4 3 5% 4 6% 7% 45%	1952
	11th to 20th	Night	13% 7% 2 6% 3 3 4 3 5% 6% 47%	1875
	21st to end	Night	11% 7% 2 5% 5% 4 4 4 6% 7% 44%	1753
May	1st to 10th	Night	12% 9% 4 7% 5% 4 4 4 6% 8% 36%	2813
	11th to 20th	Night	15% 8% 3 8% 5% 5% 4 3 5% 6% 38%	2812
	21st to end	Night	6% 6% 3 7% 6% 5% 5% 5% 6% 9% 41%	3079
June	1st to 10th	Night	6% 6% 2 7% 6% 5% 5% 4 8% 8% 43%	1710
	11th to 20th	Night	3 3 1 4 4 5% 5% 4 7% 12% 51%	1710
	21st to end	Night	5% 5% 2 6% 6% 6% 4 4 7% 12% 41%	1710
July	1st to 10th	Night	7% 5% 2 7% 4 5% 6% 6% 10% 10% 38%	2840
	11th to 20th	Night	9% 5% 1 5% 4 4 4 4 7% 11% 44%	2840
	21st to end	Night	12% 11% 5% 11% 7% 5% 7% 4 7% 9% 23%	3087
August	1st to 10th	Night	4 4 2 6% 4 4 4 4 8% 11% 49%	2825
	11th to 20th	Night	6% 6% 3 6% 4 4 4 4 7% 11% 45%	3029
	21st to end	Night	5% 4 1 4 3 3 4 4 6% 9% 56%	3476
September	1st to 10th	Night	9% 7% 3 6% 4 5% 4 3 6% 7% 44%	2003
	11th to 20th	Night	10% 8% 3 6% 4 4 3 4 6% 8% 45%	2090
	21st to end	Night	12% 5% 2 6% 4 3 3 3 4 6% 52%	2090
October	1st to 10th	Night	10% 4 2 5% 2 2 2 2 4 6% 59%	2090
	11th to 20th	Night	13% 6% 2 5% 3 3 3 3 4 5% 53%	2176
	21st to end	Night	12% 8% 3 5% 3 3 3 2 4 6% 50%	2603
November	1st to 10th	Night	10% 6% 3 6% 4 3 4 3 5% 6% 50%	2536
	11th to 20th	Night	11% 8% 3 6% 3 3 3 3 5% 7% 47%	2600
	21st to end	Night	14% 10% 4 6% 4 4 4 3 4 6% 42%	2600
December	1st to 10th	Night	18% 11% 4 8% 4 5% 4 4 5% 6% 31%	2495
	11th to 20th	Night	14% 9% 6% 10% 5% 4 3 3 5% 5% 38%	3042
	21st to end	Night	15% 10% 6% 10% 6% 6% 5% 5% 6% 7% 24%	4532

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	52% 9% 5% 16% 17% 2	2837
	11th to 20th	Day	55% 7% 5% 14% 19% 1	2840
	21st to end	Day	52% 5% 7% 20% 15% 1	3220
February	1st to 10th	Day	52% 6% 6% 15% 17% 3	1900
	11th to 20th	Day	54% 5% 6% 17% 14% 4	1858
	21st to end	Day	52% 5% 8% 13% 16% 6%	1570
March	1st to 10th	Day	55% 5% 7% 14% 11% 7%	3135
	11th to 20th	Day	40% 5% 7% 23% 17% 7%	3480
	21st to end	Day	47% 6% 9% 24% 13% 1	3815
April	1st to 10th	Day	41% 6% 11% 22% 16% 3	2244
	11th to 20th	Day	41% 6% 7% 19% 24% 3	2254
	21st to end	Day	41% 8% 10% 26% 13% 1	2427
May	1st to 10th	Day	47% 8% 10% 23% 10% 1	4120
	11th to 20th	Day	47% 10% 10% 25% 8%	4085
	21st to end	Day	40% 10% 11% 23% 16% 2	4489
June	1st to 10th	Day	42% 10% 14% 21% 12% 2	2470
	11th to 20th	Day	36% 9% 18% 22% 14% 2	2470
	21st to end	Day	37% 11% 17% 19% 13% 3	2470
July	1st to 10th	Day	39% 14% 19% 17% 9% 2	4055
	11th to 20th	Day	45% 10% 18% 19% 6% 2	4051
	21st to end	Day	62% 9% 10% 13% 4 1	4324
August	1st to 10th	Day	33% 11% 17% 29% 10%	4091
	11th to 20th	Day	36% 11% 17% 23% 12% 1	3834
	21st to end	Day	32% 11% 13% 31% 11% 1	4179
September	1st to 10th	Day	42% 9% 11% 17% 16% 5%	2157
	11th to 20th	Day	42% 8% 11% 20% 17% 2	2090
	21st to end	Day	39% 7% 10% 21% 18% 5%	2090
October	1st to 10th	Day	24% 5% 7% 19% 32% 12%	3480
	11th to 20th	Day	24% 3 6% 24% 30% 13%	3307
	21st to end	Day	29% 6% 9% 23% 23% 10%	3253
November	1st to 10th	Day	32% 6% 7% 24% 25% 5%	1762
	11th to 20th	Day	40% 5% 6% 22% 23% 6%	1800
	21st to end	Day	43% 5% 7% 21% 21% 4	1800
December	1st to 10th	Day	53% 5% 5% 20% 14% 3	1719
	11th to 20th	Day	48% 9% 7% 16% 17% 3	2150
	21st to end	Day	51% 7% 10% 19% 12% 3	3124
January	1st to 10th	Night	49% 9% 6% 18% 17% 2	4109
	11th to 20th	Night	50% 7% 6% 13% 18% 6%	4120
	21st to end	Night	54% 5% 7% 13% 18% 3	4432
February	1st to 10th	Night	49% 5% 9% 18% 15% 3	2280
	11th to 20th	Night	54% 5% 6% 18% 13% 5%	2219
	21st to end	Night	54% 6% 6% 16% 14% 4	1884
March	1st to 10th	Night	53% 9% 8% 13% 14% 4	3716
	11th to 20th	Night	37% 7% 7% 25% 14% 11%	3480
	21st to end	Night	46% 6% 8% 22% 15% 2	3817
April	1st to 10th	Night	36% 7% 10% 24% 20% 3	1952
	11th to 20th	Night	38% 5% 8% 20% 23% 5%	1875
	21st to end	Night	36% 8% 11% 30% 14% 1	1753
May	1st to 10th	Night	43% 9% 13% 24% 10% 1	2840
	11th to 20th	Night	43% 10% 13% 21% 12%	2813
	21st to end	Night	35% 12% 13% 25% 15% 1	3087
June	1st to 10th	Night	36% 10% 15% 26% 12% 2	1710
	11th to 20th	Night	24% 8% 23% 29% 14% 2	1710
	21st to end	Night	33% 10% 16% 25% 12% 4	1710
July	1st to 10th	Night	35% 12% 22% 22% 8% 1	2795
	11th to 20th	Night	32% 9% 21% 28% 8% 3	2786
	21st to end	Night	55% 11% 13% 14% 6% 1	2988
August	1st to 10th	Night	26% 9% 15% 37% 13% 1	2814
	11th to 20th	Night	29% 10% 23% 24% 13% 1	3057
	21st to end	Night	23% 7% 14% 41% 14% 1	3476
September	1st to 10th	Night	36% 9% 13% 21% 15% 6%	2003
	11th to 20th	Night	37% 7% 13% 21% 21% 1	2090
	21st to end	Night	34% 6% 11% 22% 22% 5%	2090
October	1st to 10th	Night	20% 5% 6% 25% 30% 14%	3480
	11th to 20th	Night	21% 4 6% 24% 28% 18%	3610
	21st to end	Night	24% 4 8% 25% 26% 13%	4277
November	1st to 10th	Night	35% 4 8% 22% 23% 8%	2536
	11th to 20th	Night	37% 4 6% 20% 25% 8%	2600
	21st to end	Night	43% 5% 5% 22% 21% 4	2600
December	1st to 10th	Night	53% 7% 8% 17% 13% 3	2495
	11th to 20th	Night	46% 8% 6% 16% 21% 4	3044
	21st to end	Night	53% 10% 8% 15% 12% 1	4532

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	27% 27% 33% 11% 1 1	270
	11th to 20th	Day	31% 31% 24% 11% 3	270
	21st to end	Day	24% 29% 36% 9% 1	297
February	1st to 10th	Day	25% 30% 31% 12% 1	270
	11th to 20th	Day	37% 28% 29% 4 1 1	270
	21st to end	Day	41% 24% 31% 3 1	225
March	1st to 10th	Day	28% 24% 33% 13% 1	272
	11th to 20th	Day	26% 24% 30% 16% 4 1	460
	21st to end	Day	24% 20% 34% 17% 5%	506
April	1st to 10th	Day	23% 22% 26% 21% 8% 1	460
	11th to 20th	Day	21% 17% 32% 19% 10% 1	452
	21st to end	Day	19% 16% 32% 21% 11% 2	460
May	1st to 10th	Day	19% 16% 32% 20% 10% 4	463
	11th to 20th	Day	13% 11% 28% 27% 15% 7%	487
	21st to end	Day	15% 8% 22% 27% 17% 11%	529
June	1st to 10th	Day	14% 8% 22% 27% 19% 11%	490
	11th to 20th	Day	6% 4 19% 31% 26% 14%	490
	21st to end	Day	7% 4 25% 30% 21% 13%	490
July	1st to 10th	Day	11% 4 16% 27% 25% 18%	485
	11th to 20th	Day	10% 3 16% 24% 28% 18%	484
	21st to end	Day	13% 4 13% 25% 27% 18%	532
August	1st to 10th	Day	12% 5% 16% 27% 24% 16%	486
	11th to 20th	Day	10% 4 19% 31% 25% 10%	479
	21st to end	Day	12% 4 11% 25% 31% 17%	539
September	1st to 10th	Day	11% 4 13% 29% 30% 12%	490
	11th to 20th	Day	14% 6% 12% 28% 29% 11%	490
	21st to end	Day	19% 4 19% 26% 26% 6%	490
October	1st to 10th	Day	13% 7% 23% 29% 21% 7%	490
	11th to 20th	Day	12% 15% 28% 27% 15% 2	490
	21st to end	Day	19% 13% 29% 26% 12% 2	439
November	1st to 10th	Day	16% 14% 34% 26% 8% 2	300
	11th to 20th	Day	18% 16% 43% 20% 3	300
	21st to end	Day	20% 21% 37% 15% 6% 1	300
December	1st to 10th	Day	29% 21% 33% 12% 4 1	273
	11th to 20th	Day	23% 22% 33% 17% 4	270
	21st to end	Day	28% 24% 34% 12% 2	297
January	1st to 10th	Night	22% 22% 33% 19% 4	760
	11th to 20th	Night	25% 22% 29% 19% 4	760
	21st to end	Night	21% 20% 38% 19% 2	836
February	1st to 10th	Night	20% 19% 35% 23% 3	760
	11th to 20th	Night	27% 20% 34% 17% 1	743
	21st to end	Night	29% 21% 33% 16% 1	628
March	1st to 10th	Night	19% 18% 33% 25% 4	760
	11th to 20th	Night	19% 20% 32% 22% 6% 1	760
	21st to end	Night	21% 16% 29% 26% 8%	836
April	1st to 10th	Night	16% 15% 33% 26% 10% 1	622
	11th to 20th	Night	16% 13% 33% 27% 11% 1	563
	21st to end	Night	14% 9% 32% 35% 8% 1	570
May	1st to 10th	Night	12% 11% 30% 30% 15% 2	570
	11th to 20th	Night	12% 6% 24% 32% 20% 5%	561
	21st to end	Night	9% 5% 16% 36% 30% 5%	617
June	1st to 10th	Night	8% 4 15% 38% 30% 5%	570
	11th to 20th	Night	4 2 14% 35% 37% 8%	570
	21st to end	Night	6% 2 13% 39% 32% 9%	570
July	1st to 10th	Night	10% 2 8% 29% 41% 9%	555
	11th to 20th	Night	9% 2 9% 28% 40% 12%	552
	21st to end	Night	9% 2 7% 32% 40% 9%	624
August	1st to 10th	Night	8% 2 9% 30% 42% 9%	567
	11th to 20th	Night	9% 3 12% 34% 37% 5%	564
	21st to end	Night	11% 1 7% 32% 38% 10%	627
September	1st to 10th	Night	11% 4 13% 29% 36% 7%	673
	11th to 20th	Night	14% 3 15% 31% 32% 6%	760
	21st to end	Night	14% 4 18% 31% 29% 4	760
October	1st to 10th	Night	11% 6% 21% 27% 26% 8%	760
	11th to 20th	Night	17% 8% 25% 32% 17% 2	760
	21st to end	Night	17% 9% 26% 32% 14% 2	836
November	1st to 10th	Night	13% 11% 24% 33% 16% 3	780
	11th to 20th	Night	15% 17% 31% 26% 10% 1	800
	21st to end	Night	19% 17% 27% 27% 10% 1	800
December	1st to 10th	Night	24% 18% 26% 25% 6%	768
	11th to 20th	Night	20% 16% 30% 26% 7% 1	760
	21st to end	Night	27% 18% 27% 24% 5%	836

Page generated at 2024-11-29 09:43:07. Version ac07

Copyright © 2024 Attilla Danko.