Kitt's Castle Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kitt's Castle Observatory clear sky chart from 2005-11-06 to 2026-03-03.

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	14% 11% 4 10% 5% 5% 5% 4 5% 7% 30%	131987
	Night	14% 12% 4 9% 5% 5% 4 4 5% 6% 32%	129179
Transparency	Day	52% 5% 10% 20% 12% 1	135618
	Night	52% 4 10% 20% 12% 2	133619
Seeing	Day	20% 10% 27% 23% 14% 6%	16994
	Night	20% 8% 28% 29% 13% 2	26677

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	16% 17% 8% 19% 9% 6% 4 3 4 5% 10%	5258
	11th to 20th	Day	10% 18% 7% 16% 8% 8% 7% 3 4 4 15%	5280
	21st to end	Day	17% 16% 8% 14% 8% 7% 5% 4 4 4 13%	5780
February	1st to 10th	Day	17% 16% 5% 12% 8% 5% 4 3 4 5% 21%	1890
	11th to 20th	Day	15% 13% 6% 14% 7% 4 5% 3 5% 6% 22%	1997
	21st to end	Day	16% 14% 5% 11% 5% 5% 4 4 5% 5% 26%	1730
March	1st to 10th	Day	17% 11% 8% 14% 5% 4 4 3 4 6% 24%	4719
	11th to 20th	Day	11% 12% 4 9% 5% 4 4 3 4 6% 37%	4980
	21st to end	Day	19% 13% 5% 11% 5% 4 4 4 4 5% 26%	5465
April	1st to 10th	Day	15% 14% 4 9% 6% 4 4 3 6% 7% 29%	2250
	11th to 20th	Day	16% 11% 4 8% 5% 4 4 3 5% 6% 34%	2542
	21st to end	Day	18% 9% 3 7% 5% 3 5% 4 5% 7% 33%	2600
May	1st to 10th	Day	21% 11% 3 8% 5% 4 5% 4 5% 6% 28%	5862
	11th to 20th	Day	18% 8% 3 8% 5% 4 4 3 6% 7% 33%	5861
	21st to end	Day	17% 7% 2 7% 5% 5% 5% 5% 7% 8% 34%	6433
June	1st to 10th	Day	13% 7% 2 7% 6% 5% 5% 4 6% 9% 37%	2600
	11th to 20th	Day	12% 8% 2 7% 5% 5% 5% 5% 6% 9% 35%	2700
	21st to end	Day	11% 6% 2 6% 5% 5% 6% 6% 7% 10% 37%	2800
July	1st to 10th	Day	9% 7% 3 7% 5% 5% 5% 4 6% 10% 40%	6360
	11th to 20th	Day	10% 6% 2 7% 5% 5% 6% 5% 8% 11% 35%	5900
	21st to end	Day	10% 6% 2 7% 5% 5% 5% 5% 7% 9% 37%	6424
August	1st to 10th	Day	9% 6% 3 8% 6% 5% 5% 4 7% 10% 37%	4234
	11th to 20th	Day	9% 6% 3 7% 5% 5% 6% 5% 8% 11% 36%	4174
	21st to end	Day	7% 5% 2 6% 5% 5% 6% 5% 7% 10% 42%	4642
September	1st to 10th	Day	12% 6% 2 5% 5% 4 4 4 5% 7% 47%	2210
	11th to 20th	Day	9% 7% 2 5% 5% 4 4 3 6% 9% 45%	2200
	21st to end	Day	19% 7% 2 7% 4 4 3 3 5% 5% 41%	2200
October	1st to 10th	Day	13% 8% 2 6% 4 3 3 3 6% 8% 43%	2130
	11th to 20th	Day	14% 9% 3 7% 4 4 5% 4 5% 8% 39%	2000
	21st to end	Day	19% 13% 3 6% 5% 5% 5% 3 6% 6% 29%	2129
November	1st to 10th	Day	11% 10% 2 7% 4 4 4 4 5% 7% 41%	1852
	11th to 20th	Day	17% 14% 5% 7% 5% 4 4 3 4 5% 31%	1890
	21st to end	Day	17% 18% 6% 10% 5% 4 3 3 4 6% 25%	1890
December	1st to 10th	Day	17% 14% 6% 19% 6% 4 4 3 3 4 20%	2977
	11th to 20th	Day	21% 16% 8% 13% 5% 3 4 3 3 5% 19%	3463
	21st to end	Day	22% 23% 8% 13% 5% 3 3 3 3 3 12%	4565
January	1st to 10th	Night	13% 20% 8% 19% 8% 6% 4 3 4 4 14%	7635
	11th to 20th	Night	8% 17% 10% 18% 8% 8% 6% 4 4 3 13%	7680
	21st to end	Night	17% 15% 6% 12% 6% 5% 5% 3 5% 5% 21%	8401
February	1st to 10th	Night	18% 13% 6% 12% 7% 5% 4 4 4 4 23%	2730
	11th to 20th	Night	16% 13% 5% 12% 8% 5% 5% 3 5% 5% 25%	2505
	21st to end	Night	18% 14% 5% 12% 5% 5% 4 3 4 4 25%	2076
March	1st to 10th	Night	17% 14% 5% 8% 5% 3 3 3 3 5% 32%	5178
	11th to 20th	Night	11% 9% 3 7% 4 3 4 4 6% 8% 40%	4980
	21st to end	Night	17% 10% 3 9% 5% 4 4 3 5% 6% 35%	5467
April	1st to 10th	Night	16% 12% 3 7% 5% 4 4 4 5% 7% 32%	2166
	11th to 20th	Night	16% 8% 3 7% 5% 5% 4 3 5% 7% 36%	1807
	21st to end	Night	14% 10% 3 7% 5% 5% 4 5% 6% 6% 36%	1800
May	1st to 10th	Night	22% 12% 3 8% 5% 5% 4 3 5% 6% 26%	4033
	11th to 20th	Night	15% 9% 3 7% 4 4 4 3 6% 9% 36%	4032
	21st to end	Night	14% 7% 2 6% 5% 4 4 4 7% 8% 39%	4421
June	1st to 10th	Night	10% 8% 2 6% 5% 5% 5% 4 5% 6% 45%	1800
	11th to 20th	Night	9% 5% 2 5% 4 4 6% 5% 7% 9% 42%	1691
	21st to end	Night	9% 5% 2 7% 5% 4 4 4 7% 10% 44%	1600
July	1st to 10th	Night	9% 5% 2 6% 4 5% 4 4 7% 9% 44%	3618
	11th to 20th	Night	9% 5% 2 6% 4 6% 5% 4 7% 10% 41%	4052
	21st to end	Night	8% 7% 2 7% 5% 5% 4 4 7% 9% 44%	4427
August	1st to 10th	Night	9% 7% 3 7% 5% 5% 5% 5% 6% 10% 37%	2915
	11th to 20th	Night	10% 8% 3 7% 4 4 3 4 5% 7% 43%	2875
	21st to end	Night	5% 4 2 5% 4 5% 6% 4 6% 8% 50%	3251
September	1st to 10th	Night	10% 5% 2 5% 4 3 4 4 5% 6% 52%	2170
	11th to 20th	Night	9% 5% 2 4 3 3 4 3 5% 7% 56%	2200
	21st to end	Night	15% 8% 2 6% 4 3 3 3 6% 6% 43%	2200
October	1st to 10th	Night	10% 5% 2 5% 4 4 5% 4 5% 7% 49%	2268
	11th to 20th	Night	15% 9% 3 7% 4 4 4 3 4 6% 41%	2400
	21st to end	Night	21% 9% 3 6% 4 4 4 4 5% 6% 35%	2710
November	1st to 10th	Night	13% 9% 3 7% 4 4 4 3 5% 7% 43%	2666
	11th to 20th	Night	16% 12% 5% 8% 5% 3 4 3 5% 6% 33%	2730
	21st to end	Night	18% 16% 5% 9% 4 4 4 4 5% 6% 26%	2730
December	1st to 10th	Night	15% 14% 6% 12% 7% 5% 5% 4 4 6% 22%	4380
	11th to 20th	Night	18% 18% 8% 13% 5% 4 3 3 4 4 20%	4952
	21st to end	Night	21% 22% 8% 11% 5% 4 3 3 4 5% 14%	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	78% 4 8% 8% 2	5259
	11th to 20th	Day	75% 3 6% 8% 8%	5280
	21st to end	Day	76% 3 5% 12% 5%	5780
February	1st to 10th	Day	65% 4 9% 14% 7% 1	1890
	11th to 20th	Day	64% 3 7% 17% 8% 1	2007
	21st to end	Day	60% 4 12% 16% 7% 2	1730
March	1st to 10th	Day	62% 4 7% 20% 6%	4719
	11th to 20th	Day	48% 5% 10% 27% 9% 1	4980
	21st to end	Day	59% 5% 9% 18% 9% 1	5465
April	1st to 10th	Day	54% 4 12% 18% 11% 1	2250
	11th to 20th	Day	50% 5% 12% 18% 13% 2	2542
	21st to end	Day	51% 5% 10% 21% 11% 2	2600
May	1st to 10th	Day	56% 5% 10% 17% 11% 1	5897
	11th to 20th	Day	50% 6% 13% 22% 10% 1	5865
	21st to end	Day	45% 7% 11% 23% 12% 3	6447
June	1st to 10th	Day	43% 6% 11% 24% 15% 1	2600
	11th to 20th	Day	44% 6% 13% 22% 14% 1	2700
	21st to end	Day	39% 8% 14% 21% 16% 3	2800
July	1st to 10th	Day	39% 5% 10% 29% 15% 2	6291
	11th to 20th	Day	39% 6% 15% 23% 15% 1	5831
	21st to end	Day	40% 6% 13% 20% 19% 2	6240
August	1st to 10th	Day	40% 6% 15% 24% 14% 1	4221
	11th to 20th	Day	38% 6% 12% 30% 13% 1	4213
	21st to end	Day	36% 6% 14% 29% 12% 3	4641
September	1st to 10th	Day	37% 5% 11% 24% 20% 4	2210
	11th to 20th	Day	35% 5% 11% 27% 19% 3	2200
	21st to end	Day	45% 5% 9% 21% 20% 1	2200
October	1st to 10th	Day	28% 4 12% 33% 22% 1	3468
	11th to 20th	Day	39% 4 9% 24% 20% 3	3240
	21st to end	Day	44% 4 10% 22% 19% 1	3418
November	1st to 10th	Day	42% 5% 11% 24% 16% 2	1852
	11th to 20th	Day	55% 3 9% 20% 11% 2	1890
	21st to end	Day	62% 3 10% 16% 8% 1	1890
December	1st to 10th	Day	69% 3 13% 12% 3	2977
	11th to 20th	Day	69% 3 9% 14% 5%	3460
	21st to end	Day	78% 3 5% 8% 4	4565
January	1st to 10th	Night	76% 3 6% 11% 3	7636
	11th to 20th	Night	75% 4 6% 9% 6% 1	7680
	21st to end	Night	65% 3 10% 14% 7% 1	8401
February	1st to 10th	Night	64% 4 9% 15% 8% 1	2730
	11th to 20th	Night	61% 4 8% 17% 8% 1	2506
	21st to end	Night	63% 3 9% 15% 9% 2	2076
March	1st to 10th	Night	55% 4 9% 21% 9% 1	5178
	11th to 20th	Night	41% 5% 12% 30% 11% 2	4980
	21st to end	Night	50% 4 8% 21% 15% 1	5467
April	1st to 10th	Night	52% 5% 11% 16% 14% 2	2166
	11th to 20th	Night	47% 5% 10% 18% 17% 3	1807
	21st to end	Night	47% 5% 11% 21% 15% 2	1800
May	1st to 10th	Night	58% 6% 9% 14% 11% 3	4060
	11th to 20th	Night	45% 6% 11% 23% 15% 1	4033
	21st to end	Night	41% 6% 13% 27% 12% 2	4429
June	1st to 10th	Night	39% 5% 11% 25% 19% 2	1800
	11th to 20th	Night	35% 7% 14% 24% 16% 3	1691
	21st to end	Night	36% 6% 14% 25% 16% 4	1600
July	1st to 10th	Night	35% 6% 13% 26% 16% 4	3580
	11th to 20th	Night	37% 6% 14% 27% 14% 1	4002
	21st to end	Night	36% 5% 13% 21% 23% 2	4297
August	1st to 10th	Night	40% 6% 14% 24% 14% 1	2904
	11th to 20th	Night	39% 5% 10% 28% 17% 1	2902
	21st to end	Night	30% 6% 13% 31% 16% 3	3251
September	1st to 10th	Night	33% 5% 12% 28% 18% 6%	2170
	11th to 20th	Night	29% 4 10% 29% 26% 3	2200
	21st to end	Night	40% 5% 10% 21% 22% 2	2200
October	1st to 10th	Night	26% 4 7% 31% 31% 2	3710
	11th to 20th	Night	36% 3 9% 26% 21% 4	3899
	21st to end	Night	38% 3 8% 28% 19% 4	4371
November	1st to 10th	Night	42% 4 10% 24% 18% 3	2666
	11th to 20th	Night	52% 3 9% 21% 12% 3	2730
	21st to end	Night	59% 4 11% 17% 7% 1	2730
December	1st to 10th	Night	64% 5% 9% 16% 6% 1	4380
	11th to 20th	Night	68% 3 11% 13% 4	4954
	21st to end	Night	73% 4 8% 11% 4	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	27% 16% 38% 14% 5% 1	330
	11th to 20th	Day	26% 20% 42% 8% 4	330
	21st to end	Day	26% 20% 33% 18% 3	363
February	1st to 10th	Day	25% 17% 38% 17% 3 1	330
	11th to 20th	Day	25% 21% 33% 18% 2	330
	21st to end	Day	23% 25% 39% 12% 1	273
March	1st to 10th	Day	24% 16% 37% 19% 4	395
	11th to 20th	Day	25% 15% 36% 18% 4 1	500
	21st to end	Day	30% 13% 31% 21% 4 1	550
April	1st to 10th	Day	25% 12% 35% 19% 8% 2	500
	11th to 20th	Day	21% 17% 30% 20% 9% 4	492
	21st to end	Day	25% 11% 33% 20% 8% 2	500
May	1st to 10th	Day	30% 6% 30% 23% 9% 3	503
	11th to 20th	Day	22% 7% 29% 24% 13% 5%	527
	21st to end	Day	14% 6% 26% 26% 19% 8%	573
June	1st to 10th	Day	16% 5% 22% 35% 17% 5%	530
	11th to 20th	Day	16% 6% 23% 30% 21% 4	630
	21st to end	Day	14% 6% 26% 30% 18% 6%	730
July	1st to 10th	Day	13% 4 17% 28% 23% 14%	721
	11th to 20th	Day	13% 2 20% 30% 23% 12%	524
	21st to end	Day	13% 4 18% 25% 28% 13%	576
August	1st to 10th	Day	11% 3 14% 28% 29% 16%	526
	11th to 20th	Day	15% 3 17% 29% 25% 12%	519
	21st to end	Day	12% 3 15% 29% 27% 14%	583
September	1st to 10th	Day	15% 3 18% 25% 26% 14%	530
	11th to 20th	Day	11% 2 12% 26% 31% 18%	530
	21st to end	Day	21% 8% 17% 26% 20% 9%	530
October	1st to 10th	Day	14% 5% 25% 28% 20% 9%	530
	11th to 20th	Day	15% 12% 34% 25% 11% 3	530
	21st to end	Day	29% 11% 33% 21% 5% 1	512
November	1st to 10th	Day	17% 15% 35% 21% 9% 3	330
	11th to 20th	Day	25% 17% 32% 17% 8% 1	330
	21st to end	Day	28% 16% 37% 16% 2	330
December	1st to 10th	Day	25% 18% 36% 14% 5% 1	314
	11th to 20th	Day	26% 21% 35% 17% 2	330
	21st to end	Day	33% 16% 33% 16% 2	363
January	1st to 10th	Night	25% 15% 37% 20% 3	840
	11th to 20th	Night	27% 17% 37% 16% 3 1	840
	21st to end	Night	25% 15% 36% 20% 4	924
February	1st to 10th	Night	25% 11% 39% 22% 3	840
	11th to 20th	Night	24% 15% 35% 23% 3	823
	21st to end	Night	27% 12% 40% 18% 3	692
March	1st to 10th	Night	24% 12% 34% 23% 6%	809
	11th to 20th	Night	21% 12% 37% 23% 6% 1	800
	21st to end	Night	24% 10% 34% 25% 6%	880
April	1st to 10th	Night	23% 11% 35% 26% 5% 1	766
	11th to 20th	Night	21% 10% 35% 23% 10% 2	593
	21st to end	Night	21% 6% 38% 26% 7% 1	600
May	1st to 10th	Night	24% 5% 31% 31% 9% 1	600
	11th to 20th	Night	24% 3 26% 32% 13% 2	591
	21st to end	Night	12% 3 21% 40% 21% 3	650
June	1st to 10th	Night	12% 3 23% 43% 18% 2	600
	11th to 20th	Night	12% 3 19% 43% 22% 1	600
	21st to end	Night	12% 2 20% 41% 23% 3	600
July	1st to 10th	Night	11% 1 13% 43% 28% 4	585
	11th to 20th	Night	11% 2 15% 40% 28% 4	582
	21st to end	Night	9% 2 13% 42% 31% 3	657
August	1st to 10th	Night	9% 1 9% 46% 30% 4	597
	11th to 20th	Night	12% 2 10% 40% 31% 5%	594
	21st to end	Night	7% 2 12% 40% 33% 6%	660
September	1st to 10th	Night	14% 3 14% 36% 28% 6%	770
	11th to 20th	Night	12% 2 13% 35% 33% 6%	800
	21st to end	Night	19% 4 21% 32% 20% 4	800
October	1st to 10th	Night	13% 3 26% 34% 20% 4	800
	11th to 20th	Night	21% 8% 30% 30% 10% 2	800
	21st to end	Night	26% 9% 30% 25% 9%	880
November	1st to 10th	Night	18% 8% 34% 28% 11% 1	820
	11th to 20th	Night	23% 14% 32% 24% 6% 1	840
	21st to end	Night	27% 12% 33% 23% 5%	840
December	1st to 10th	Night	28% 14% 33% 22% 4	840
	11th to 20th	Night	27% 12% 35% 22% 4 1	840
	21st to end	Night	31% 13% 33% 21% 3	924

Page generated at 2026-02-28 01:40:22. Version ac07

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