Claiborne West Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Claiborne West Park clear sky chart from 2005-11-06 to 2026-02-16.

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% 7% 2 7% 5% 5% 5% 4 6% 8% 38%	130847
	Night	14% 7% 2 6% 4 4 4 3 5% 7% 44%	130238
Transparency	Day	41% 6% 12% 18% 16% 7%	134455
	Night	38% 5% 12% 19% 17% 8%	134708
Seeing	Day	13% 7% 20% 26% 22% 11%	16528
	Night	15% 6% 20% 31% 24% 4	26452

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	17% 9% 3 7% 4 3 3 3 4 5% 41%	5289
	11th to 20th	Day	12% 6% 2 6% 4 3 4 3 4 5% 51%	5310
	21st to end	Day	26% 8% 3 8% 4 3 3 3 4 5% 33%	5812
February	1st to 10th	Day	21% 8% 3 6% 5% 5% 3 3 5% 6% 36%	1890
	11th to 20th	Day	22% 9% 3 7% 4 4 3 3 4 4 37%	2082
	21st to end	Day	24% 10% 3 6% 4 3 3 2 4 5% 36%	1815
March	1st to 10th	Day	23% 8% 3 6% 4 4 5% 3 5% 5% 33%	4936
	11th to 20th	Day	15% 7% 3 7% 4 4 4 3 5% 6% 43%	4980
	21st to end	Day	19% 8% 3 7% 5% 4 4 3 4 5% 38%	5462
April	1st to 10th	Day	15% 8% 3 8% 4 5% 5% 4 5% 7% 37%	2262
	11th to 20th	Day	16% 7% 3 7% 5% 4 5% 4 6% 6% 37%	2374
	21st to end	Day	11% 6% 2 7% 5% 5% 5% 4 7% 7% 41%	2400
May	1st to 10th	Day	18% 8% 3 8% 6% 6% 6% 4 7% 7% 27%	5405
	11th to 20th	Day	10% 6% 2 7% 5% 4 5% 4 5% 8% 43%	5579
	21st to end	Day	8% 6% 3 8% 6% 6% 7% 5% 8% 11% 33%	6434
June	1st to 10th	Day	6% 6% 2 9% 6% 7% 7% 6% 7% 11% 33%	2600
	11th to 20th	Day	5% 5% 2 7% 7% 7% 8% 6% 8% 10% 34%	2600
	21st to end	Day	6% 6% 2 8% 9% 8% 7% 7% 9% 11% 26%	2600
July	1st to 10th	Day	7% 6% 2 8% 6% 7% 7% 6% 9% 12% 28%	5900
	11th to 20th	Day	7% 6% 3 9% 7% 7% 7% 6% 9% 12% 27%	5900
	21st to end	Day	10% 7% 3 9% 6% 6% 6% 5% 7% 10% 31%	6422
August	1st to 10th	Day	2 2 1 4 4 5% 6% 6% 7% 11% 53%	4201
	11th to 20th	Day	3 2 2 5% 4 5% 7% 6% 8% 13% 45%	3849
	21st to end	Day	9% 6% 2 8% 7% 7% 7% 5% 7% 8% 34%	4312
September	1st to 10th	Day	9% 6% 3 9% 5% 6% 6% 5% 7% 9% 36%	2380
	11th to 20th	Day	13% 6% 3 7% 6% 6% 5% 5% 6% 7% 36%	2200
	21st to end	Day	10% 5% 3 6% 5% 4 5% 5% 6% 9% 44%	2180
October	1st to 10th	Day	6% 4 2 6% 5% 4 4 4 5% 6% 55%	2000
	11th to 20th	Day	9% 4 2 6% 4 4 3 3 5% 8% 53%	2000
	21st to end	Day	12% 5% 2 5% 4 3 3 3 5% 6% 52%	2200
November	1st to 10th	Day	11% 5% 2 6% 4 6% 5% 3 5% 6% 47%	2058
	11th to 20th	Day	11% 6% 3 6% 4 3 4 3 4 6% 50%	2100
	21st to end	Day	15% 8% 2 7% 4 4 3 3 4 7% 43%	2100
December	1st to 10th	Day	22% 9% 2 6% 3 3 3 2 4 6% 38%	3147
	11th to 20th	Day	15% 9% 3 8% 4 4 4 3 4 6% 41%	3481
	21st to end	Day	17% 7% 2 6% 3 3 3 3 5% 6% 46%	4587
January	1st to 10th	Night	16% 8% 2 6% 3 3 3 3 4 6% 46%	7634
	11th to 20th	Night	15% 7% 3 5% 4 3 3 3 4 5% 48%	7680
	21st to end	Night	28% 9% 2 7% 4 3 3 2 4 5% 31%	8402
February	1st to 10th	Night	19% 8% 3 7% 3 4 3 3 5% 6% 40%	2730
	11th to 20th	Night	22% 9% 3 5% 3 2 3 2 4 6% 40%	2329
	21st to end	Night	21% 10% 3 7% 4 4 4 2 5% 5% 36%	1815
March	1st to 10th	Night	22% 12% 3 6% 3 3 3 3 4 5% 36%	4919
	11th to 20th	Night	22% 8% 2 6% 4 3 3 2 3 5% 41%	4980
	21st to end	Night	20% 9% 3 6% 4 4 3 3 4 5% 41%	5467
April	1st to 10th	Night	18% 7% 2 5% 5% 4 4 4 5% 7% 39%	2136
	11th to 20th	Night	17% 5% 2 5% 3 3 4 3 6% 8% 44%	1975
	21st to end	Night	13% 7% 2 5% 4 4 5% 3 5% 8% 44%	2000
May	1st to 10th	Night	24% 10% 3 8% 4 4 4 4 6% 8% 25%	4490
	11th to 20th	Night	16% 7% 2 6% 4 4 4 3 5% 8% 40%	4317
	21st to end	Night	14% 8% 3 7% 5% 5% 5% 4 7% 10% 32%	4443
June	1st to 10th	Night	4 4 2 4 4 4 5% 4 8% 10% 52%	1800
	11th to 20th	Night	4 4 1 5% 3 4 4 4 7% 13% 50%	1800
	21st to end	Night	6% 5% 2 6% 4 5% 6% 5% 9% 11% 42%	1800
July	1st to 10th	Night	4 5% 2 7% 5% 4 5% 4 7% 14% 42%	4078
	11th to 20th	Night	3 4 2 6% 5% 5% 6% 4 8% 11% 44%	4077
	21st to end	Night	6% 6% 2 8% 5% 5% 5% 4 6% 9% 43%	4449
August	1st to 10th	Night	2 1 1 2 2 3 4 4 6% 10% 65%	2954
	11th to 20th	Night	2 2 1 3 2 3 4 4 7% 12% 61%	3200
	21st to end	Night	7% 4 2 6% 4 5% 6% 5% 8% 10% 42%	3586
September	1st to 10th	Night	7% 5% 2 7% 4 4 4 5% 8% 10% 45%	2015
	11th to 20th	Night	10% 6% 3 6% 4 5% 5% 4 6% 9% 42%	2200
	21st to end	Night	8% 5% 2 5% 3 4 3 3 5% 7% 57%	2200
October	1st to 10th	Night	6% 3 1 4 4 3 4 3 6% 7% 58%	2400
	11th to 20th	Night	9% 4 1 4 3 3 3 3 5% 7% 59%	2400
	21st to end	Night	11% 5% 2 3 3 2 2 2 4 5% 60%	2640
November	1st to 10th	Night	10% 6% 1 5% 5% 3 4 3 5% 5% 52%	2460
	11th to 20th	Night	11% 5% 2 4 3 3 4 3 5% 6% 55%	2520
	21st to end	Night	13% 6% 3 8% 5% 4 3 3 5% 6% 45%	2520
December	1st to 10th	Night	22% 10% 3 7% 4 4 3 3 4 6% 35%	4243
	11th to 20th	Night	15% 10% 3 7% 4 3 3 2 4 5% 42%	4946
	21st to end	Night	16% 9% 3 5% 4 3 3 3 4 5% 45%	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	46% 4 5% 21% 17% 6%	5290
	11th to 20th	Day	35% 4 6% 17% 26% 12%	5310
	21st to end	Day	54% 4 4 13% 15% 10%	5812
February	1st to 10th	Day	49% 4 7% 14% 17% 10%	1890
	11th to 20th	Day	49% 4 7% 14% 16% 9%	2093
	21st to end	Day	52% 5% 7% 13% 16% 8%	1815
March	1st to 10th	Day	51% 4 7% 10% 16% 10%	4936
	11th to 20th	Day	42% 5% 7% 12% 20% 15%	4980
	21st to end	Day	47% 5% 8% 19% 18% 3	5464
April	1st to 10th	Day	46% 6% 9% 15% 16% 9%	2262
	11th to 20th	Day	44% 4 10% 16% 16% 9%	2374
	21st to end	Day	39% 7% 11% 16% 22% 5%	2400
May	1st to 10th	Day	52% 6% 11% 18% 9% 3	5440
	11th to 20th	Day	38% 5% 15% 21% 19% 2	5583
	21st to end	Day	40% 9% 16% 25% 9% 1	6447
June	1st to 10th	Day	39% 9% 17% 21% 14% 1	2600
	11th to 20th	Day	39% 8% 15% 24% 12% 2	2600
	21st to end	Day	43% 10% 20% 19% 7%	2600
July	1st to 10th	Day	41% 10% 28% 18% 2	5836
	11th to 20th	Day	45% 11% 26% 17% 2	5831
	21st to end	Day	44% 10% 18% 24% 4	6240
August	1st to 10th	Day	21% 8% 15% 36% 20%	4187
	11th to 20th	Day	27% 10% 32% 28% 3	3885
	21st to end	Day	45% 10% 13% 17% 14% 2	4311
September	1st to 10th	Day	41% 10% 15% 16% 14% 4	2380
	11th to 20th	Day	43% 8% 14% 17% 14% 4	2200
	21st to end	Day	35% 6% 12% 21% 16% 10%	2180
October	1st to 10th	Day	22% 4 7% 13% 18% 36%	3260
	11th to 20th	Day	19% 3 4 21% 34% 19%	3240
	21st to end	Day	25% 3 6% 12% 42% 12%	3538
November	1st to 10th	Day	36% 5% 9% 19% 19% 11%	2058
	11th to 20th	Day	34% 4 9% 18% 22% 13%	2100
	21st to end	Day	41% 4 7% 19% 20% 8%	2100
December	1st to 10th	Day	48% 3 6% 16% 21% 5%	3147
	11th to 20th	Day	44% 5% 7% 14% 21% 11%	3479
	21st to end	Day	40% 4 6% 17% 24% 10%	4587
January	1st to 10th	Night	40% 3 10% 19% 21% 7%	7635
	11th to 20th	Night	39% 3 4 17% 24% 12%	7680
	21st to end	Night	56% 3 4 13% 16% 9%	8402
February	1st to 10th	Night	46% 3 7% 12% 20% 12%	2730
	11th to 20th	Night	47% 4 7% 16% 18% 9%	2329
	21st to end	Night	49% 4 8% 13% 13% 12%	1815
March	1st to 10th	Night	50% 3 7% 13% 16% 11%	4919
	11th to 20th	Night	47% 4 7% 12% 14% 16%	4980
	21st to end	Night	46% 4 9% 15% 20% 7%	5467
April	1st to 10th	Night	44% 5% 10% 17% 15% 9%	2136
	11th to 20th	Night	37% 4 13% 18% 16% 13%	1975
	21st to end	Night	37% 4 12% 21% 20% 6%	2000
May	1st to 10th	Night	55% 6% 11% 15% 9% 3	4520
	11th to 20th	Night	42% 5% 12% 19% 19% 2	4318
	21st to end	Night	43% 6% 20% 22% 8% 1	4452
June	1st to 10th	Night	25% 8% 21% 31% 14% 1	1800
	11th to 20th	Night	25% 8% 19% 31% 14% 2	1800
	21st to end	Night	31% 11% 25% 25% 8%	1800
July	1st to 10th	Night	32% 8% 38% 20% 2	4035
	11th to 20th	Night	31% 10% 34% 23% 2	4026
	21st to end	Night	37% 9% 20% 28% 6%	4320
August	1st to 10th	Night	14% 6% 20% 41% 18%	2944
	11th to 20th	Night	16% 8% 36% 34% 5%	3230
	21st to end	Night	35% 13% 18% 20% 13% 1	3586
September	1st to 10th	Night	32% 9% 21% 21% 13% 4	2015
	11th to 20th	Night	37% 7% 17% 20% 15% 4	2200
	21st to end	Night	28% 6% 13% 24% 18% 11%	2200
October	1st to 10th	Night	19% 3 7% 16% 18% 36%	3920
	11th to 20th	Night	16% 3 5% 25% 31% 21%	3899
	21st to end	Night	22% 3 5% 13% 40% 17%	4252
November	1st to 10th	Night	32% 5% 10% 19% 22% 12%	2460
	11th to 20th	Night	30% 4 9% 19% 25% 13%	2520
	21st to end	Night	40% 4 9% 18% 18% 11%	2520
December	1st to 10th	Night	52% 3 6% 16% 17% 6%	4243
	11th to 20th	Night	45% 3 7% 12% 20% 12%	4947
	21st to end	Night	41% 5% 6% 15% 24% 9%	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	24% 12% 38% 17% 8% 1	330
	11th to 20th	Day	17% 17% 35% 24% 6% 1	330
	21st to end	Day	24% 20% 31% 21% 4	363
February	1st to 10th	Day	23% 17% 36% 21% 4	330
	11th to 20th	Day	31% 16% 30% 21% 2	315
	21st to end	Day	28% 19% 38% 11% 4	249
March	1st to 10th	Day	26% 17% 32% 21% 4	300
	11th to 20th	Day	15% 20% 46% 15% 4 1	300
	21st to end	Day	21% 16% 34% 24% 5% 1	330
April	1st to 10th	Day	19% 17% 33% 24% 7%	362
	11th to 20th	Day	19% 18% 27% 23% 13% 1	492
	21st to end	Day	16% 8% 32% 28% 15% 1	500
May	1st to 10th	Day	16% 14% 26% 29% 15% 1	503
	11th to 20th	Day	13% 6% 22% 37% 19% 3	598
	21st to end	Day	9% 5% 25% 35% 21% 5%	789
June	1st to 10th	Day	8% 2 15% 32% 28% 14%	730
	11th to 20th	Day	7% 2 14% 36% 30% 11%	730
	21st to end	Day	8% 2 12% 28% 32% 17%	730
July	1st to 10th	Day	8% 2 6% 26% 35% 23%	721
	11th to 20th	Day	6% 2 6% 25% 36% 25%	718
	21st to end	Day	7% 2 4 26% 37% 24%	794
August	1st to 10th	Day	4 3 22% 45% 25%	706
	11th to 20th	Day	6% 3 11% 44% 35%	519
	21st to end	Day	12% 3 5% 19% 35% 26%	583
September	1st to 10th	Day	10% 2 6% 24% 35% 23%	510
	11th to 20th	Day	12% 2 8% 23% 34% 21%	330
	21st to end	Day	12% 2 9% 29% 37% 12%	330
October	1st to 10th	Day	8% 2 14% 43% 24% 9%	330
	11th to 20th	Day	8% 4 20% 36% 22% 9%	330
	21st to end	Day	15% 9% 24% 31% 17% 5%	363
November	1st to 10th	Day	16% 5% 25% 30% 21% 3	330
	11th to 20th	Day	13% 6% 30% 37% 13% 1	330
	21st to end	Day	16% 20% 29% 24% 9% 2	330
December	1st to 10th	Day	22% 9% 33% 23% 10% 4	330
	11th to 20th	Day	20% 10% 36% 27% 6% 1	330
	21st to end	Day	19% 14% 33% 25% 7% 2	363
January	1st to 10th	Night	22% 8% 32% 30% 7%	1050
	11th to 20th	Night	21% 9% 32% 30% 8%	1050
	21st to end	Night	25% 8% 29% 32% 6%	1155
February	1st to 10th	Night	22% 11% 32% 31% 4	1050
	11th to 20th	Night	27% 11% 26% 29% 7%	733
	21st to end	Night	23% 10% 34% 29% 3	495
March	1st to 10th	Night	23% 8% 31% 32% 6%	600
	11th to 20th	Night	19% 9% 31% 33% 8%	600
	21st to end	Night	19% 6% 32% 33% 10%	660
April	1st to 10th	Night	20% 8% 29% 35% 8%	600
	11th to 20th	Night	19% 9% 26% 33% 13%	593
	21st to end	Night	15% 7% 30% 36% 12% 1	600
May	1st to 10th	Night	16% 7% 25% 41% 11%	600
	11th to 20th	Night	13% 5% 22% 39% 20% 1	591
	21st to end	Night	6% 4 20% 38% 27% 4	650
June	1st to 10th	Night	5% 2 7% 37% 44% 6%	600
	11th to 20th	Night	6% 2 7% 38% 42% 6%	600
	21st to end	Night	9% 2 6% 27% 45% 11%	600
July	1st to 10th	Night	6% 2 2 24% 51% 14%	585
	11th to 20th	Night	4 1 2 19% 52% 21%	582
	21st to end	Night	4 1 3 25% 51% 16%	657
August	1st to 10th	Night	2 1 2 18% 61% 17%	597
	11th to 20th	Night	4 1 15% 60% 19%	594
	21st to end	Night	8% 2 4 19% 52% 15%	660
September	1st to 10th	Night	7% 3 6% 23% 49% 13%	600
	11th to 20th	Night	12% 2 5% 22% 51% 9%	600
	21st to end	Night	9% 1 6% 32% 44% 8%	600
October	1st to 10th	Night	6% 2 10% 36% 41% 5%	800
	11th to 20th	Night	10% 3 18% 39% 28% 3	800
	21st to end	Night	13% 6% 19% 38% 23% 3	880
November	1st to 10th	Night	12% 4 20% 36% 25% 3	820
	11th to 20th	Night	13% 6% 23% 41% 17%	840
	21st to end	Night	16% 8% 30% 31% 14% 1	840
December	1st to 10th	Night	23% 7% 26% 30% 13%	965
	11th to 20th	Night	22% 8% 28% 32% 10%	1050
	21st to end	Night	21% 9% 30% 32% 9%	1155

Page generated at 2026-02-13 00:42:15. Version ac07

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