Capon Springs and Farms
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Capon Springs and Farms 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	13% 6% 2 6% 5% 5% 5% 4 6% 7% 41%	114065
	Night	12% 6% 2 6% 4 4 5% 4 6% 8% 43%	115209
Transparency	Day	39% 7% 11% 23% 16% 4	117710
	Night	37% 6% 12% 24% 17% 3	119703
Seeing	Day	21% 16% 26% 21% 12% 4	15571
	Night	18% 15% 25% 29% 12% 1	25311

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	12% 6% 3 7% 5% 5% 5% 4 5% 5% 44%	3941
	11th to 20th	Day	10% 8% 3 8% 5% 5% 4 3 4 6% 43%	4060
	21st to end	Day	13% 6% 3 7% 6% 5% 4 4 5% 6% 42%	4466
February	1st to 10th	Day	11% 10% 3 8% 6% 3 5% 3 6% 6% 38%	1800
	11th to 20th	Day	15% 9% 3 7% 5% 4 5% 4 4 6% 38%	1753
	21st to end	Day	15% 8% 3 6% 5% 4 4 3 4 7% 40%	1678
March	1st to 10th	Day	15% 7% 2 6% 5% 5% 4 3 5% 6% 41%	4935
	11th to 20th	Day	9% 6% 2 6% 4 4 4 4 6% 7% 49%	4980
	21st to end	Day	13% 8% 2 8% 4 4 5% 4 6% 7% 38%	5465
April	1st to 10th	Day	11% 8% 3 7% 5% 6% 5% 5% 6% 7% 38%	2372
	11th to 20th	Day	12% 6% 2 6% 4 5% 4 3 6% 7% 44%	2374
	21st to end	Day	16% 7% 2 6% 4 4 5% 4 6% 6% 40%	2465
May	1st to 10th	Day	19% 7% 3 8% 5% 5% 5% 5% 6% 8% 29%	4212
	11th to 20th	Day	22% 7% 3 6% 4 4 5% 4 6% 8% 31%	4234
	21st to end	Day	10% 5% 2 6% 4 5% 6% 5% 8% 9% 41%	4893
June	1st to 10th	Day	12% 6% 2 4 5% 5% 5% 5% 6% 9% 41%	2660
	11th to 20th	Day	9% 6% 2 6% 5% 6% 5% 6% 8% 9% 37%	2660
	21st to end	Day	9% 5% 1 5% 5% 5% 6% 5% 7% 9% 43%	2660
July	1st to 10th	Day	5% 5% 2 6% 5% 6% 6% 5% 8% 10% 43%	4410
	11th to 20th	Day	8% 5% 2 6% 5% 5% 6% 5% 8% 11% 39%	4120
	21st to end	Day	11% 8% 3 7% 6% 5% 6% 5% 6% 8% 36%	4466
August	1st to 10th	Day	15% 5% 2 7% 5% 6% 6% 5% 8% 9% 32%	4104
	11th to 20th	Day	8% 5% 2 7% 5% 5% 6% 5% 7% 9% 40%	3994
	21st to end	Day	10% 4 2 6% 3 5% 4 4 7% 8% 47%	4180
September	1st to 10th	Day	15% 6% 2 6% 3 4 4 4 6% 6% 44%	2280
	11th to 20th	Day	13% 6% 2 6% 4 4 4 4 6% 7% 45%	2212
	21st to end	Day	21% 6% 2 6% 5% 5% 4 3 5% 6% 38%	2019
October	1st to 10th	Day	16% 5% 2 5% 4 3 4 4 5% 7% 45%	1900
	11th to 20th	Day	16% 5% 2 5% 4 4 4 3 5% 6% 48%	1900
	21st to end	Day	13% 5% 2 6% 3 4 3 3 6% 6% 49%	2090
November	1st to 10th	Day	10% 5% 2 5% 3 4 5% 3 5% 6% 52%	1952
	11th to 20th	Day	14% 7% 2 4 5% 4 5% 4 5% 7% 45%	1680
	21st to end	Day	14% 5% 2 5% 4 4 6% 4 5% 7% 44%	1600
December	1st to 10th	Day	11% 6% 2 5% 3 4 5% 3 6% 7% 48%	2600
	11th to 20th	Day	17% 8% 3 5% 4 4 5% 4 5% 6% 38%	2990
	21st to end	Day	16% 7% 3 7% 6% 5% 6% 4 7% 8% 32%	3960
January	1st to 10th	Night	9% 7% 2 6% 5% 4 4 4 6% 8% 45%	5999
	11th to 20th	Night	11% 8% 3 6% 3 4 4 4 6% 6% 46%	5900
	21st to end	Night	13% 7% 3 5% 3 3 4 4 6% 6% 46%	6490
February	1st to 10th	Night	13% 8% 3 6% 5% 4 5% 4 6% 6% 41%	2600
	11th to 20th	Night	15% 8% 3 6% 5% 3 5% 4 5% 6% 38%	2533
	21st to end	Night	14% 9% 3 6% 5% 4 4 4 5% 7% 39%	1948
March	1st to 10th	Night	15% 6% 2 6% 4 3 4 3 5% 7% 47%	4918
	11th to 20th	Night	8% 5% 2 6% 4 4 4 4 5% 9% 49%	4980
	21st to end	Night	9% 6% 3 7% 5% 5% 5% 4 5% 7% 45%	5467
April	1st to 10th	Night	14% 8% 2 7% 5% 4 5% 5% 5% 7% 38%	2026
	11th to 20th	Night	13% 6% 2 6% 5% 4 5% 4 6% 8% 42%	1975
	21st to end	Night	15% 6% 2 4 5% 4 5% 3 5% 7% 44%	1950
May	1st to 10th	Night	21% 7% 3 7% 5% 4 5% 4 6% 8% 31%	2903
	11th to 20th	Night	24% 8% 3 6% 5% 5% 4 3 4 6% 34%	2877
	21st to end	Night	10% 4 2 5% 5% 4 5% 4 7% 9% 43%	2778
June	1st to 10th	Night	10% 4 2 4 4 4 5% 4 6% 9% 46%	1520
	11th to 20th	Night	10% 5% 2 6% 4 5% 4 5% 6% 10% 43%	1520
	21st to end	Night	9% 5% 1 4 4 4 5% 4 8% 12% 43%	1520
July	1st to 10th	Night	6% 4 2 6% 5% 6% 6% 6% 7% 11% 42%	2544
	11th to 20th	Night	6% 6% 2 7% 6% 6% 7% 4 7% 10% 39%	2840
	21st to end	Night	8% 6% 3 8% 5% 5% 6% 5% 8% 9% 37%	3087
August	1st to 10th	Night	15% 5% 3 7% 6% 5% 5% 5% 7% 8% 35%	2825
	11th to 20th	Night	8% 5% 3 6% 5% 5% 5% 4 7% 9% 43%	2803
	21st to end	Night	13% 4 2 5% 3 4 4 4 6% 9% 47%	3476
September	1st to 10th	Night	14% 6% 2 5% 3 5% 5% 4 5% 7% 45%	1900
	11th to 20th	Night	13% 6% 2 5% 3 3 2 3 5% 8% 50%	1965
	21st to end	Night	20% 4 2 6% 4 4 4 3 4 6% 43%	2159
October	1st to 10th	Night	19% 5% 2 5% 3 3 3 3 4 6% 47%	2280
	11th to 20th	Night	14% 4 2 4 4 3 4 3 5% 6% 52%	2280
	21st to end	Night	14% 5% 1 4 2 4 4 3 5% 7% 50%	2508
November	1st to 10th	Night	10% 6% 2 5% 3 4 3 3 5% 7% 52%	2342
	11th to 20th	Night	13% 7% 2 4 4 3 4 3 6% 7% 46%	2715
	21st to end	Night	12% 5% 2 6% 5% 5% 5% 5% 6% 6% 44%	2800
December	1st to 10th	Night	9% 4 2 6% 3 4 4 4 6% 9% 49%	4580
	11th to 20th	Night	16% 7% 2 6% 5% 5% 5% 4 5% 7% 38%	5205
	21st to end	Night	14% 7% 3 7% 6% 5% 6% 5% 7% 9% 32%	6996

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	39% 6% 5% 23% 20% 6%	3942
	11th to 20th	Day	41% 5% 7% 19% 18% 10%	4060
	21st to end	Day	41% 5% 10% 26% 14% 4	4466
February	1st to 10th	Day	46% 5% 13% 21% 13% 2	1800
	11th to 20th	Day	46% 7% 9% 19% 16% 2	1762
	21st to end	Day	43% 5% 12% 20% 15% 4	1678
March	1st to 10th	Day	43% 4 9% 21% 15% 8%	4935
	11th to 20th	Day	33% 5% 10% 26% 20% 6%	4980
	21st to end	Day	43% 7% 10% 18% 17% 6%	5465
April	1st to 10th	Day	42% 7% 11% 19% 16% 5%	2372
	11th to 20th	Day	38% 6% 11% 22% 19% 5%	2374
	21st to end	Day	43% 6% 10% 23% 14% 3	2465
May	1st to 10th	Day	50% 9% 11% 20% 9% 1	4250
	11th to 20th	Day	49% 8% 10% 23% 8% 1	4238
	21st to end	Day	34% 11% 14% 23% 16% 2	4907
June	1st to 10th	Day	38% 9% 13% 24% 16% 1	2660
	11th to 20th	Day	38% 12% 13% 22% 13% 2	2660
	21st to end	Day	35% 9% 15% 25% 15% 2	2660
July	1st to 10th	Day	34% 10% 17% 24% 11% 5%	4340
	11th to 20th	Day	35% 10% 14% 30% 10% 1	4051
	21st to end	Day	43% 8% 8% 23% 16% 1	4324
August	1st to 10th	Day	45% 9% 15% 22% 8%	4091
	11th to 20th	Day	36% 8% 13% 26% 16% 1	4033
	21st to end	Day	33% 7% 15% 27% 16% 1	4180
September	1st to 10th	Day	39% 7% 12% 18% 20% 4	2280
	11th to 20th	Day	36% 7% 8% 26% 19% 3	2212
	21st to end	Day	47% 5% 9% 20% 17% 1	2019
October	1st to 10th	Day	33% 6% 8% 21% 27% 5%	3160
	11th to 20th	Day	26% 5% 9% 28% 22% 10%	3140
	21st to end	Day	25% 4 10% 30% 27% 5%	3428
November	1st to 10th	Day	32% 5% 11% 25% 23% 4	1952
	11th to 20th	Day	38% 5% 10% 20% 23% 4	1680
	21st to end	Day	39% 6% 11% 25% 17% 2	1600
December	1st to 10th	Day	34% 6% 13% 26% 16% 5%	2600
	11th to 20th	Day	45% 5% 12% 24% 11% 2	2986
	21st to end	Day	44% 8% 16% 18% 13% 1	3960
January	1st to 10th	Night	33% 6% 9% 26% 23% 3	5999
	11th to 20th	Night	36% 5% 9% 24% 18% 8%	5900
	21st to end	Night	38% 5% 9% 28% 17% 3	6490
February	1st to 10th	Night	42% 6% 13% 25% 13% 1	2600
	11th to 20th	Night	44% 7% 9% 22% 15% 4	2535
	21st to end	Night	45% 6% 11% 20% 14% 5%	1948
March	1st to 10th	Night	37% 5% 9% 27% 15% 8%	4918
	11th to 20th	Night	31% 6% 13% 27% 18% 5%	4980
	21st to end	Night	36% 7% 11% 23% 18% 4	5467
April	1st to 10th	Night	43% 7% 9% 20% 16% 3	2026
	11th to 20th	Night	38% 7% 11% 22% 17% 5%	1975
	21st to end	Night	39% 6% 10% 27% 14% 3	1950
May	1st to 10th	Night	51% 8% 11% 18% 10% 2	2930
	11th to 20th	Night	50% 7% 11% 22% 9% 1	2878
	21st to end	Night	34% 9% 17% 27% 9% 4	2785
June	1st to 10th	Night	33% 9% 12% 29% 15% 2	1520
	11th to 20th	Night	36% 9% 15% 26% 13% 1	1520
	21st to end	Night	32% 8% 18% 24% 17% 2	1520
July	1st to 10th	Night	33% 11% 21% 18% 13% 5%	2504
	11th to 20th	Night	37% 10% 17% 23% 11% 1	2786
	21st to end	Night	38% 10% 16% 21% 15%	2988
August	1st to 10th	Night	44% 9% 16% 24% 7%	2814
	11th to 20th	Night	35% 7% 16% 24% 18%	2830
	21st to end	Night	33% 6% 15% 30% 14% 1	3476
September	1st to 10th	Night	38% 7% 12% 21% 19% 4	1900
	11th to 20th	Night	34% 4 9% 29% 21% 2	1965
	21st to end	Night	43% 6% 9% 23% 18% 2	2159
October	1st to 10th	Night	36% 5% 10% 23% 23% 3	3800
	11th to 20th	Night	23% 5% 12% 23% 30% 7%	3779
	21st to end	Night	22% 4 10% 32% 27% 5%	4120
November	1st to 10th	Night	31% 6% 12% 25% 21% 5%	2342
	11th to 20th	Night	36% 6% 9% 25% 19% 5%	2715
	21st to end	Night	38% 6% 12% 23% 19% 3	2800
December	1st to 10th	Night	31% 6% 13% 30% 18% 2	4580
	11th to 20th	Night	45% 5% 13% 19% 16% 3	5208
	21st to end	Night	43% 8% 15% 19% 15%	6996

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	35% 32% 21% 9% 3	275
	11th to 20th	Day	32% 28% 25% 12% 3	300
	21st to end	Day	29% 27% 31% 11% 2	330
February	1st to 10th	Day	32% 30% 27% 9% 2	300
	11th to 20th	Day	45% 29% 24% 2	300
	21st to end	Day	33% 25% 28% 14% 1	389
March	1st to 10th	Day	29% 26% 23% 19% 3	500
	11th to 20th	Day	27% 29% 23% 15% 6% 1	500
	21st to end	Day	25% 26% 28% 15% 5% 1	550
April	1st to 10th	Day	24% 27% 25% 17% 6%	500
	11th to 20th	Day	22% 20% 28% 17% 10% 3	492
	21st to end	Day	25% 18% 29% 18% 8% 2	500
May	1st to 10th	Day	23% 21% 26% 17% 10% 4	503
	11th to 20th	Day	24% 18% 27% 17% 12% 3	527
	21st to end	Day	18% 13% 24% 24% 15% 5%	549
June	1st to 10th	Day	17% 11% 28% 24% 16% 4	490
	11th to 20th	Day	16% 12% 26% 22% 18% 5%	490
	21st to end	Day	12% 9% 31% 29% 14% 5%	490
July	1st to 10th	Day	11% 6% 21% 31% 22% 10%	485
	11th to 20th	Day	6% 3 26% 31% 24% 9%	484
	21st to end	Day	13% 8% 21% 31% 18% 8%	532
August	1st to 10th	Day	13% 6% 21% 27% 24% 10%	486
	11th to 20th	Day	14% 5% 20% 29% 23% 10%	479
	21st to end	Day	10% 7% 20% 28% 22% 12%	539
September	1st to 10th	Day	17% 11% 20% 22% 23% 9%	490
	11th to 20th	Day	16% 5% 20% 29% 22% 9%	490
	21st to end	Day	29% 10% 21% 20% 14% 4	490
October	1st to 10th	Day	20% 7% 22% 28% 18% 4	490
	11th to 20th	Day	19% 18% 25% 23% 12% 3	490
	21st to end	Day	17% 17% 34% 20% 9% 3	539
November	1st to 10th	Day	17% 16% 31% 23% 10% 3	492
	11th to 20th	Day	20% 22% 33% 17% 7% 1	280
	21st to end	Day	26% 20% 36% 15% 3 1	200
December	1st to 10th	Day	25% 29% 30% 13% 4 1	200
	11th to 20th	Day	28% 24% 27% 17% 5%	200
	21st to end	Day	22% 20% 30% 21% 5%	220
January	1st to 10th	Night	20% 25% 34% 18% 3	800
	11th to 20th	Night	23% 22% 28% 24% 4	800
	21st to end	Night	20% 23% 35% 21% 2	880
February	1st to 10th	Night	18% 24% 30% 26% 2	800
	11th to 20th	Night	25% 30% 27% 17% 1	783
	21st to end	Night	25% 23% 31% 18% 3	660
March	1st to 10th	Night	20% 23% 33% 21% 3	800
	11th to 20th	Night	25% 23% 26% 22% 4 1	800
	21st to end	Night	18% 23% 33% 21% 5% 1	880
April	1st to 10th	Night	22% 23% 29% 22% 4	800
	11th to 20th	Night	18% 19% 30% 25% 9%	791
	21st to end	Night	19% 16% 26% 31% 7% 1	750
May	1st to 10th	Night	22% 9% 27% 28% 15% 1	600
	11th to 20th	Night	20% 8% 25% 32% 14% 1	579
	21st to end	Night	13% 6% 22% 36% 21% 2	423
June	1st to 10th	Night	10% 6% 27% 34% 22% 1	380
	11th to 20th	Night	12% 6% 16% 39% 23% 3	380
	21st to end	Night	9% 3 21% 48% 17% 1	380
July	1st to 10th	Night	10% 2 15% 40% 28% 5%	381
	11th to 20th	Night	8% 3 14% 37% 35% 4	552
	21st to end	Night	9% 3 17% 39% 30% 3	624
August	1st to 10th	Night	10% 3 13% 43% 29% 3	567
	11th to 20th	Night	11% 5% 12% 40% 28% 4	569
	21st to end	Night	11% 4 12% 40% 28% 4	836
September	1st to 10th	Night	17% 4 14% 31% 30% 5%	760
	11th to 20th	Night	15% 5% 17% 31% 29% 4	760
	21st to end	Night	23% 5% 21% 28% 21% 2	760
October	1st to 10th	Night	20% 9% 17% 29% 21% 3	760
	11th to 20th	Night	16% 14% 23% 33% 13% 1	760
	21st to end	Night	17% 15% 25% 32% 10% 1	836
November	1st to 10th	Night	13% 15% 27% 33% 11% 1	780
	11th to 20th	Night	19% 19% 27% 26% 8% 1	800
	21st to end	Night	18% 20% 29% 26% 7% 1	800
December	1st to 10th	Night	20% 19% 30% 26% 5% 1	800
	11th to 20th	Night	19% 17% 31% 29% 3	800
	21st to end	Night	18% 20% 28% 32% 3	880

Page generated at 2025-05-23 09:20:58. Version ac07

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