Kittanning
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kittanning clear sky chart from 2005-11-06 to 2026-01-17.

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	17% 11% 4 9% 5% 5% 4 3 5% 7% 30%	127243
	Night	18% 11% 4 9% 5% 4 4 3 5% 6% 31%	124453
Transparency	Day	52% 7% 11% 19% 10% 1	130843
	Night	53% 6% 11% 18% 10% 1	128922
Seeing	Day	25% 15% 27% 19% 11% 4	16167
	Night	23% 12% 26% 26% 11% 1	25866

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% 20% 9% 22% 5% 3 2 2 3 3 14%	3983
	11th to 20th	Day	13% 23% 10% 18% 9% 6% 3 2 2 2 13%	4114
	21st to end	Day	22% 20% 6% 12% 7% 5% 4 3 4 4 15%	4466
February	1st to 10th	Day	20% 18% 5% 10% 8% 5% 4 2 3 4 20%	1800
	11th to 20th	Day	18% 15% 6% 13% 5% 5% 5% 3 5% 5% 20%	1753
	21st to end	Day	20% 14% 4 10% 5% 5% 4 2 5% 6% 23%	1635
March	1st to 10th	Day	17% 12% 6% 9% 5% 4 4 2 4 5% 33%	4935
	11th to 20th	Day	14% 11% 5% 8% 5% 5% 5% 3 5% 6% 35%	4980
	21st to end	Day	18% 11% 3 9% 5% 5% 4 4 5% 6% 31%	5465
April	1st to 10th	Day	18% 13% 3 7% 5% 5% 4 4 6% 6% 29%	2335
	11th to 20th	Day	18% 11% 3 7% 5% 5% 5% 3 5% 6% 33%	2377
	21st to end	Day	22% 9% 3 7% 4 5% 3 3 4 6% 34%	2600
May	1st to 10th	Day	22% 10% 3 8% 5% 5% 5% 4 6% 6% 27%	5862
	11th to 20th	Day	19% 8% 3 8% 5% 5% 4 4 6% 8% 29%	5902
	21st to end	Day	20% 8% 3 6% 4 4 5% 4 7% 8% 32%	6934
June	1st to 10th	Day	15% 7% 3 6% 6% 6% 5% 4 6% 8% 34%	2800
	11th to 20th	Day	15% 8% 3 6% 5% 4 5% 4 7% 9% 33%	2800
	21st to end	Day	15% 6% 2 6% 5% 4 5% 4 7% 9% 37%	2800
July	1st to 10th	Day	11% 7% 2 6% 5% 5% 5% 4 5% 9% 41%	6360
	11th to 20th	Day	12% 7% 2 8% 5% 5% 6% 4 7% 9% 34%	5908
	21st to end	Day	12% 6% 3 7% 5% 4 5% 4 6% 8% 40%	6424
August	1st to 10th	Day	17% 8% 3 8% 5% 6% 6% 4 6% 8% 29%	4234
	11th to 20th	Day	13% 7% 3 7% 4 5% 5% 4 6% 9% 36%	4174
	21st to end	Day	10% 5% 2 6% 5% 5% 6% 5% 8% 10% 40%	4416
September	1st to 10th	Day	16% 6% 2 6% 4 3 4 3 4 7% 44%	2400
	11th to 20th	Day	12% 6% 2 6% 4 4 4 4 6% 9% 45%	2252
	21st to end	Day	21% 8% 3 6% 4 4 4 4 5% 7% 34%	2171
October	1st to 10th	Day	16% 7% 2 7% 3 4 4 3 6% 7% 40%	2000
	11th to 20th	Day	20% 7% 3 7% 4 4 5% 4 5% 6% 34%	2000
	21st to end	Day	24% 10% 3 6% 4 4 4 3 4 7% 31%	2200
November	1st to 10th	Day	13% 8% 2 7% 5% 4 4 4 5% 7% 41%	1999
	11th to 20th	Day	18% 16% 3 8% 4 4 4 3 5% 6% 29%	1686
	21st to end	Day	19% 17% 5% 8% 5% 5% 4 4 5% 5% 23%	1680
December	1st to 10th	Day	20% 17% 10% 20% 5% 3 3 3 3 3 15%	2680
	11th to 20th	Day	22% 18% 6% 11% 4 3 3 3 4 5% 22%	3070
	21st to end	Day	24% 20% 6% 11% 5% 4 4 2 3 4 16%	4048
January	1st to 10th	Night	16% 18% 8% 23% 5% 4 3 2 3 4 15%	6179
	11th to 20th	Night	14% 18% 9% 17% 9% 6% 4 3 3 4 13%	5979
	21st to end	Night	24% 17% 6% 12% 5% 5% 5% 3 3 3 18%	6490
February	1st to 10th	Night	20% 15% 5% 12% 6% 5% 4 3 4 4 23%	2600
	11th to 20th	Night	18% 14% 5% 13% 6% 5% 4 3 4 5% 23%	2533
	21st to end	Night	20% 13% 4 12% 6% 4 4 3 4 6% 24%	1989
March	1st to 10th	Night	21% 11% 5% 8% 5% 3 3 3 4 5% 31%	4918
	11th to 20th	Night	14% 11% 4 6% 4 3 3 3 5% 7% 40%	4980
	21st to end	Night	17% 11% 3 7% 5% 5% 4 3 4 5% 36%	5467
April	1st to 10th	Night	20% 13% 4 6% 4 4 5% 3 4 6% 32%	2065
	11th to 20th	Night	17% 9% 3 7% 4 4 5% 4 5% 6% 37%	1975
	21st to end	Night	17% 8% 3 6% 5% 5% 5% 3 5% 8% 35%	1814
May	1st to 10th	Night	28% 10% 3 7% 4 4 3 3 5% 6% 26%	4033
	11th to 20th	Night	19% 10% 3 7% 4 4 4 3 5% 6% 35%	3987
	21st to end	Night	21% 7% 2 6% 4 4 4 3 6% 8% 35%	3920
June	1st to 10th	Night	11% 7% 2 7% 5% 4 5% 4 6% 8% 43%	1600
	11th to 20th	Night	12% 6% 2 6% 4 4 5% 4 5% 10% 41%	1600
	21st to end	Night	11% 6% 2 5% 5% 5% 5% 4 8% 9% 40%	1600
July	1st to 10th	Night	14% 7% 3 7% 4 4 4 3 5% 8% 42%	3598
	11th to 20th	Night	13% 5% 2 7% 5% 5% 5% 4 7% 10% 35%	4045
	21st to end	Night	11% 6% 2 8% 5% 4 4 3 6% 8% 43%	4427
August	1st to 10th	Night	15% 7% 3 8% 4 5% 4 4 6% 7% 37%	2915
	11th to 20th	Night	15% 7% 2 6% 4 4 5% 3 4 7% 42%	2875
	21st to end	Night	10% 4 2 6% 4 4 6% 4 6% 9% 45%	3449
September	1st to 10th	Night	13% 6% 2 5% 3 3 4 3 5% 7% 49%	2000
	11th to 20th	Night	9% 4 2 5% 3 3 4 3 5% 9% 52%	2145
	21st to end	Night	18% 8% 3 7% 4 4 4 3 5% 6% 38%	2228
October	1st to 10th	Night	15% 6% 2 5% 4 4 4 4 4 6% 45%	2400
	11th to 20th	Night	18% 8% 3 6% 4 4 4 3 5% 7% 39%	2400
	21st to end	Night	23% 9% 3 6% 3 4 3 3 4 7% 35%	2640
November	1st to 10th	Night	14% 9% 2 6% 4 4 4 3 5% 6% 42%	2516
	11th to 20th	Night	19% 12% 4 7% 5% 4 4 3 5% 6% 29%	2931
	21st to end	Night	20% 15% 5% 7% 5% 4 4 3 5% 5% 27%	2940
December	1st to 10th	Night	18% 18% 11% 14% 4 4 3 3 4 5% 16%	4720
	11th to 20th	Night	23% 16% 7% 10% 4 3 3 3 4 4 22%	5345
	21st to end	Night	23% 18% 5% 11% 5% 4 4 3 4 5% 17%	7150

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	77% 4 7% 8% 4	3984
	11th to 20th	Day	80% 3 6% 7% 3 1	4114
	21st to end	Day	73% 4 8% 10% 5%	4466
February	1st to 10th	Day	69% 4 8% 13% 6%	1800
	11th to 20th	Day	65% 6% 10% 13% 6%	1762
	21st to end	Day	62% 5% 10% 15% 6% 1	1635
March	1st to 10th	Day	52% 6% 12% 21% 8% 1	4935
	11th to 20th	Day	48% 7% 15% 20% 8% 2	4980
	21st to end	Day	53% 6% 8% 20% 12% 1	5465
April	1st to 10th	Day	54% 6% 11% 16% 11% 2	2335
	11th to 20th	Day	51% 7% 10% 18% 13% 2	2377
	21st to end	Day	51% 6% 11% 19% 12% 1	2600
May	1st to 10th	Day	55% 9% 10% 16% 8% 3	5897
	11th to 20th	Day	50% 9% 11% 19% 9% 1	5906
	21st to end	Day	46% 9% 14% 19% 10% 2	6949
June	1st to 10th	Day	45% 10% 13% 21% 11% 1	2800
	11th to 20th	Day	45% 9% 14% 19% 12% 1	2800
	21st to end	Day	42% 9% 12% 25% 11% 1	2800
July	1st to 10th	Day	41% 7% 10% 26% 14% 2	6290
	11th to 20th	Day	43% 7% 14% 25% 11%	5838
	21st to end	Day	40% 7% 10% 22% 20% 1	6240
August	1st to 10th	Day	50% 8% 14% 19% 8%	4221
	11th to 20th	Day	42% 8% 13% 26% 10% 1	4213
	21st to end	Day	36% 9% 13% 28% 12% 2	4416
September	1st to 10th	Day	40% 7% 10% 23% 17% 3	2400
	11th to 20th	Day	35% 7% 16% 25% 15% 1	2252
	21st to end	Day	49% 8% 11% 19% 13% 1	2171
October	1st to 10th	Day	35% 5% 11% 29% 18% 1	3260
	11th to 20th	Day	44% 6% 11% 21% 13% 4	3240
	21st to end	Day	40% 5% 11% 28% 15% 1	3538
November	1st to 10th	Day	43% 6% 13% 19% 16% 2	1999
	11th to 20th	Day	55% 7% 11% 17% 8% 2	1686
	21st to end	Day	62% 6% 11% 15% 5% 1	1680
December	1st to 10th	Day	77% 4 9% 8% 3	2680
	11th to 20th	Day	67% 4 12% 14% 3	3066
	21st to end	Day	73% 4 9% 9% 5%	4048
January	1st to 10th	Night	75% 4 7% 10% 3	6179
	11th to 20th	Night	75% 5% 9% 8% 2	5979
	21st to end	Night	72% 4 8% 10% 4 1	6490
February	1st to 10th	Night	65% 5% 9% 15% 6%	2600
	11th to 20th	Night	63% 6% 10% 14% 6%	2535
	21st to end	Night	61% 5% 9% 15% 9% 1	1989
March	1st to 10th	Night	57% 5% 10% 21% 7%	4918
	11th to 20th	Night	44% 6% 15% 24% 8% 3	4980
	21st to end	Night	49% 6% 11% 17% 16% 1	5467
April	1st to 10th	Night	54% 7% 9% 17% 13% 1	2065
	11th to 20th	Night	47% 8% 11% 17% 15% 3	1975
	21st to end	Night	46% 6% 12% 22% 11% 3	1814
May	1st to 10th	Night	58% 7% 10% 13% 10% 3	4060
	11th to 20th	Night	48% 9% 10% 22% 10% 1	3988
	21st to end	Night	44% 9% 12% 21% 10% 3	3927
June	1st to 10th	Night	37% 10% 12% 24% 14% 2	1600
	11th to 20th	Night	38% 10% 14% 24% 13% 2	1600
	21st to end	Night	38% 10% 13% 22% 16% 1	1600
July	1st to 10th	Night	42% 6% 11% 23% 17% 2	3560
	11th to 20th	Night	41% 9% 17% 21% 11% 1	3995
	21st to end	Night	38% 6% 11% 20% 24% 1	4297
August	1st to 10th	Night	46% 8% 13% 21% 11% 1	2904
	11th to 20th	Night	40% 7% 10% 30% 12% 1	2902
	21st to end	Night	33% 9% 14% 29% 12% 2	3449
September	1st to 10th	Night	34% 7% 12% 22% 20% 4	2000
	11th to 20th	Night	30% 7% 13% 28% 21% 1	2145
	21st to end	Night	46% 7% 12% 18% 15% 1	2228
October	1st to 10th	Night	36% 5% 9% 25% 23% 1	3920
	11th to 20th	Night	38% 6% 11% 22% 16% 6%	3899
	21st to end	Night	37% 5% 12% 26% 19% 1	4252
November	1st to 10th	Night	42% 6% 12% 22% 16% 3	2516
	11th to 20th	Night	54% 6% 11% 18% 9% 3	2931
	21st to end	Night	57% 7% 11% 19% 5% 1	2940
December	1st to 10th	Night	71% 5% 11% 9% 3	4720
	11th to 20th	Night	67% 4 12% 14% 3	5348
	21st to end	Night	68% 7% 10% 12% 3	7150

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	36% 26% 23% 11% 3 1	292
	11th to 20th	Day	40% 28% 25% 5% 2 1	318
	21st to end	Day	34% 26% 29% 8% 3	330
February	1st to 10th	Day	36% 24% 33% 6% 1	300
	11th to 20th	Day	42% 25% 28% 5% 1	300
	21st to end	Day	36% 28% 29% 6% 1	304
March	1st to 10th	Day	32% 22% 29% 13% 3	500
	11th to 20th	Day	35% 19% 30% 11% 5% 1	500
	21st to end	Day	34% 21% 27% 14% 3 1	550
April	1st to 10th	Day	33% 21% 26% 15% 5% 1	500
	11th to 20th	Day	28% 21% 27% 14% 8% 3	492
	21st to end	Day	29% 19% 29% 16% 5% 2	500
May	1st to 10th	Day	30% 16% 28% 17% 7% 3	503
	11th to 20th	Day	26% 13% 30% 17% 10% 4	527
	21st to end	Day	21% 10% 25% 24% 14% 5%	573
June	1st to 10th	Day	18% 14% 28% 25% 12% 3	530
	11th to 20th	Day	21% 14% 24% 24% 13% 4	530
	21st to end	Day	18% 9% 31% 26% 13% 3	530
July	1st to 10th	Day	15% 4 23% 28% 20% 9%	525
	11th to 20th	Day	11% 9% 27% 29% 17% 8%	524
	21st to end	Day	13% 5% 28% 30% 17% 6%	576
August	1st to 10th	Day	14% 6% 24% 26% 21% 8%	526
	11th to 20th	Day	16% 7% 22% 27% 18% 10%	519
	21st to end	Day	12% 6% 25% 28% 19% 10%	583
September	1st to 10th	Day	17% 8% 22% 25% 19% 9%	530
	11th to 20th	Day	12% 4 22% 30% 23% 10%	530
	21st to end	Day	27% 13% 21% 23% 13% 4	530
October	1st to 10th	Day	19% 12% 24% 22% 19% 5%	530
	11th to 20th	Day	25% 15% 28% 21% 8% 2	530
	21st to end	Day	32% 14% 29% 17% 7%	583
November	1st to 10th	Day	21% 18% 31% 19% 9% 2	477
	11th to 20th	Day	33% 21% 29% 11% 5% 2	223
	21st to end	Day	29% 21% 39% 10% 1	220
December	1st to 10th	Day	33% 29% 27% 8% 3 1	220
	11th to 20th	Day	38% 22% 29% 9% 2	220
	21st to end	Day	41% 17% 28% 11% 3	242
January	1st to 10th	Night	29% 23% 31% 13% 3	840
	11th to 20th	Night	34% 19% 31% 14% 3	825
	21st to end	Night	31% 20% 30% 16% 3	880
February	1st to 10th	Night	33% 16% 29% 20% 2	800
	11th to 20th	Night	32% 21% 32% 14% 1	783
	21st to end	Night	30% 17% 33% 18% 2	660
March	1st to 10th	Night	27% 17% 34% 21% 2	800
	11th to 20th	Night	31% 18% 25% 20% 6%	800
	21st to end	Night	26% 16% 34% 20% 4 1	880
April	1st to 10th	Night	29% 15% 29% 21% 5%	800
	11th to 20th	Night	24% 15% 32% 20% 8% 1	791
	21st to end	Night	20% 11% 32% 30% 6%	614
May	1st to 10th	Night	24% 9% 24% 34% 9% 1	600
	11th to 20th	Night	22% 7% 29% 33% 9%	572
	21st to end	Night	12% 6% 25% 33% 21% 3	433
June	1st to 10th	Night	12% 6% 28% 38% 15% 1	400
	11th to 20th	Night	13% 6% 24% 38% 18% 1	400
	21st to end	Night	12% 3 27% 38% 19% 1	400
July	1st to 10th	Night	11% 2 20% 40% 23% 3	390
	11th to 20th	Night	12% 5% 14% 37% 28% 4	571
	21st to end	Night	13% 2 16% 41% 27% 1	657
August	1st to 10th	Night	10% 4 16% 43% 25% 2	597
	11th to 20th	Night	14% 4 12% 38% 28% 4	594
	21st to end	Night	12% 4 18% 34% 28% 4	795
September	1st to 10th	Night	14% 4 22% 34% 23% 3	800
	11th to 20th	Night	11% 4 18% 35% 29% 4	800
	21st to end	Night	21% 9% 21% 27% 18% 4	800
October	1st to 10th	Night	19% 8% 22% 30% 21% 2	800
	11th to 20th	Night	23% 11% 30% 27% 9% 1	800
	21st to end	Night	28% 13% 26% 26% 7%	880
November	1st to 10th	Night	19% 12% 30% 29% 10%	820
	11th to 20th	Night	29% 15% 27% 23% 6% 1	840
	21st to end	Night	30% 15% 31% 19% 5%	840
December	1st to 10th	Night	33% 20% 27% 17% 3	840
	11th to 20th	Night	31% 20% 29% 17% 3	840
	21st to end	Night	31% 19% 28% 21% 2	924

Page generated at 2026-01-14 01:14:26. Version ac07

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