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 2024-06-17.

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	18% 11% 4 8% 5% 4 4 3 5% 7% 30%	89341
	Night	18% 12% 4 8% 5% 4 4 3 5% 6% 31%	89471
Transparency	Day	53% 8% 12% 18% 9% 1	89108
	Night	52% 7% 11% 18% 9% 1	89308
Seeing	Day	25% 15% 27% 19% 10% 4	14140
	Night	23% 12% 26% 26% 11% 1	23822

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	19% 23% 11% 12% 4 3 2 2 3 4 17%	2718
	11th to 20th	Day	13% 23% 8% 17% 8% 4 3 2 3 3 16%	2840
	21st to end	Day	27% 20% 7% 14% 6% 4 4 2 3 3 11%	3124
February	1st to 10th	Day	19% 19% 5% 10% 8% 5% 4 2 3 4 20%	1710
	11th to 20th	Day	17% 15% 6% 13% 5% 5% 5% 3 5% 5% 21%	1663
	21st to end	Day	21% 14% 5% 10% 5% 5% 4 2 5% 6% 23%	1555
March	1st to 10th	Day	20% 11% 5% 8% 5% 4 4 3 5% 6% 30%	3435
	11th to 20th	Day	14% 13% 6% 9% 5% 4 4 3 4 6% 31%	3480
	21st to end	Day	19% 10% 3 8% 5% 5% 4 4 5% 6% 32%	3815
April	1st to 10th	Day	17% 13% 3 7% 5% 5% 5% 4 6% 6% 30%	2218
	11th to 20th	Day	18% 11% 3 7% 5% 5% 5% 3 5% 6% 33%	2257
	21st to end	Day	22% 10% 3 7% 5% 5% 3 3 4 6% 33%	2470
May	1st to 10th	Day	25% 9% 3 7% 4 5% 4 3 5% 6% 29%	4082
	11th to 20th	Day	20% 9% 3 8% 5% 5% 5% 4 6% 7% 29%	4108
	21st to end	Day	13% 7% 2 6% 5% 4 5% 4 7% 9% 39%	4823
June	1st to 10th	Day	15% 7% 3 6% 6% 6% 5% 4 6% 8% 33%	2660
	11th to 20th	Day	14% 8% 3 6% 5% 4 6% 4 7% 8% 34%	2607
	21st to end	Day	15% 6% 2 6% 5% 4 5% 3 7% 10% 36%	2520
July	1st to 10th	Day	12% 7% 2 6% 5% 5% 6% 4 5% 9% 38%	2520
	11th to 20th	Day	12% 8% 2 6% 5% 5% 5% 4 7% 9% 36%	2348
	21st to end	Day	12% 7% 3 8% 5% 5% 6% 5% 7% 8% 33%	2547
August	1st to 10th	Day	11% 6% 2 7% 6% 7% 7% 5% 7% 10% 32%	2327
	11th to 20th	Day	14% 7% 3 7% 5% 5% 5% 5% 6% 10% 33%	2303
	21st to end	Day	13% 6% 2 6% 4 6% 6% 4 7% 9% 36%	2435
September	1st to 10th	Day	18% 6% 2 6% 4 4 4 3 4 7% 41%	2160
	11th to 20th	Day	13% 6% 2 6% 4 4 3 4 6% 9% 43%	2028
	21st to end	Day	19% 7% 3 6% 4 4 4 4 5% 7% 37%	1955
October	1st to 10th	Day	17% 8% 3 7% 3 4 4 4 6% 7% 36%	1800
	11th to 20th	Day	22% 8% 3 7% 3 5% 5% 4 5% 6% 33%	1800
	21st to end	Day	25% 11% 3 6% 4 4 4 3 4 7% 29%	1980
November	1st to 10th	Day	13% 8% 2 7% 5% 4 4 4 5% 7% 40%	1805
	11th to 20th	Day	18% 15% 3 7% 4 4 4 3 5% 6% 30%	1526
	21st to end	Day	19% 17% 4 7% 5% 5% 4 4 5% 5% 24%	1520
December	1st to 10th	Day	21% 20% 7% 11% 6% 4 4 3 4 4 17%	1520
	11th to 20th	Day	19% 19% 7% 12% 4 3 3 3 4 5% 20%	1910
	21st to end	Day	27% 22% 7% 10% 5% 3 3 2 3 4 15%	2772
January	1st to 10th	Night	18% 21% 9% 11% 5% 4 3 3 3 4 18%	4224
	11th to 20th	Night	16% 19% 8% 14% 6% 7% 4 3 4 4 15%	4120
	21st to end	Night	30% 17% 7% 11% 5% 4 2 2 3 3 16%	4532
February	1st to 10th	Night	20% 15% 4 12% 6% 5% 4 3 4 4 24%	2470
	11th to 20th	Night	18% 14% 5% 12% 5% 5% 4 3 4 5% 24%	2403
	21st to end	Night	20% 13% 4 11% 5% 4 4 3 4 6% 25%	1893
March	1st to 10th	Night	23% 12% 3 6% 4 4 3 3 4 6% 32%	3418
	11th to 20th	Night	19% 13% 6% 7% 4 3 3 3 4 6% 33%	3480
	21st to end	Night	17% 10% 3 7% 4 4 3 3 4 5% 40%	3817
April	1st to 10th	Night	19% 13% 3 7% 4 4 5% 3 4 6% 33%	1962
	11th to 20th	Night	17% 8% 3 7% 4 4 4 4 5% 6% 37%	1875
	21st to end	Night	16% 8% 3 6% 5% 5% 5% 3 5% 8% 35%	1724
May	1st to 10th	Night	28% 9% 2 6% 4 4 3 3 5% 6% 29%	2813
	11th to 20th	Night	18% 10% 3 7% 5% 4 4 4 5% 7% 34%	2781
	21st to end	Night	13% 7% 2 6% 4 4 4 4 6% 10% 39%	2732
June	1st to 10th	Night	10% 6% 2 7% 5% 4 5% 4 6% 8% 43%	1520
	11th to 20th	Night	12% 6% 2 6% 4 4 5% 4 5% 9% 42%	1496
	21st to end	Night	11% 6% 2 5% 5% 5% 5% 4 8% 9% 41%	1440
July	1st to 10th	Night	9% 7% 2 7% 5% 5% 4 3 5% 8% 44%	1440
	11th to 20th	Night	11% 5% 2 6% 4 4 5% 4 6% 10% 44%	1608
	21st to end	Night	11% 6% 2 7% 5% 4 5% 5% 8% 10% 37%	1771
August	1st to 10th	Night	8% 5% 2 7% 4 4 5% 4 7% 9% 45%	1611
	11th to 20th	Night	11% 7% 2 7% 4 4 5% 3 5% 9% 43%	1598
	21st to end	Night	12% 5% 2 5% 4 4 5% 4 6% 9% 44%	1903
September	1st to 10th	Night	13% 6% 2 6% 4 4 4 4 5% 7% 47%	1800
	11th to 20th	Night	10% 4 2 5% 3 3 4 4 5% 9% 51%	1930
	21st to end	Night	16% 8% 3 6% 4 4 3 3 5% 6% 41%	2004
October	1st to 10th	Night	15% 7% 2 5% 4 4 5% 4 4 6% 43%	2160
	11th to 20th	Night	19% 8% 3 6% 4 4 4 3 5% 7% 38%	2160
	21st to end	Night	24% 10% 3 7% 3 4 3 3 4 7% 32%	2376
November	1st to 10th	Night	14% 10% 2 6% 4 4 4 3 4 6% 42%	2270
	11th to 20th	Night	19% 12% 4 7% 5% 4 4 3 5% 7% 30%	2651
	21st to end	Night	19% 14% 4 7% 5% 4 4 3 6% 6% 28%	2660
December	1st to 10th	Night	22% 19% 7% 9% 5% 4 3 3 4 5% 18%	2660
	11th to 20th	Night	20% 17% 6% 11% 5% 3 4 3 4 5% 22%	3285
	21st to end	Night	24% 19% 6% 10% 6% 5% 4 3 5% 4 14%	4884

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	72% 5% 8% 10% 5%	2719
	11th to 20th	Day	74% 4 8% 11% 3	2840
	21st to end	Day	79% 5% 7% 7% 2	3124
February	1st to 10th	Day	69% 4 8% 12% 6%	1710
	11th to 20th	Day	65% 6% 10% 13% 6%	1672
	21st to end	Day	63% 5% 10% 15% 6% 1	1555
March	1st to 10th	Day	53% 7% 12% 22% 6%	3435
	11th to 20th	Day	52% 8% 15% 18% 6% 1	3480
	21st to end	Day	51% 8% 10% 20% 11% 1	3815
April	1st to 10th	Day	53% 7% 11% 17% 11% 2	2218
	11th to 20th	Day	51% 7% 10% 17% 14% 2	2257
	21st to end	Day	51% 6% 11% 19% 11% 1	2470
May	1st to 10th	Day	54% 9% 10% 19% 7% 1	4120
	11th to 20th	Day	51% 10% 12% 18% 8% 1	4112
	21st to end	Day	38% 11% 15% 22% 12% 3	4837
June	1st to 10th	Day	46% 10% 13% 20% 10% 1	2660
	11th to 20th	Day	44% 9% 14% 20% 12% 1	2607
	21st to end	Day	43% 9% 12% 26% 10% 1	2520
July	1st to 10th	Day	44% 9% 11% 20% 13% 3	2450
	11th to 20th	Day	41% 9% 14% 24% 12% 1	2278
	21st to end	Day	43% 11% 13% 19% 13% 1	2405
August	1st to 10th	Day	43% 11% 16% 23% 7%	2314
	11th to 20th	Day	44% 9% 15% 21% 10% 1	2303
	21st to end	Day	40% 10% 13% 22% 12% 3	2435
September	1st to 10th	Day	42% 7% 10% 21% 16% 3	2160
	11th to 20th	Day	37% 7% 16% 25% 14% 1	2028
	21st to end	Day	46% 8% 11% 21% 14% 1	1955
October	1st to 10th	Day	45% 8% 14% 19% 14% 1	1800
	11th to 20th	Day	50% 7% 12% 22% 8%	1800
	21st to end	Day	55% 6% 12% 16% 9% 1	1980
November	1st to 10th	Day	43% 7% 14% 18% 16% 2	1805
	11th to 20th	Day	54% 7% 11% 18% 8% 2	1526
	21st to end	Day	61% 7% 12% 15% 5% 1	1520
December	1st to 10th	Day	72% 5% 9% 10% 3	1520
	11th to 20th	Day	67% 5% 11% 14% 3	1906
	21st to end	Day	76% 4 9% 9% 2	2772
January	1st to 10th	Night	70% 6% 9% 12% 3	4224
	11th to 20th	Night	72% 7% 10% 9% 2	4120
	21st to end	Night	74% 5% 7% 11% 3 1	4532
February	1st to 10th	Night	64% 5% 9% 16% 6%	2470
	11th to 20th	Night	62% 6% 10% 15% 6%	2405
	21st to end	Night	61% 5% 10% 15% 9% 1	1893
March	1st to 10th	Night	54% 6% 10% 24% 7%	3418
	11th to 20th	Night	51% 7% 14% 21% 6% 1	3480
	21st to end	Night	45% 7% 11% 21% 14% 1	3817
April	1st to 10th	Night	52% 7% 9% 17% 13% 1	1962
	11th to 20th	Night	46% 8% 11% 17% 15% 3	1875
	21st to end	Night	46% 6% 12% 21% 11% 3	1724
May	1st to 10th	Night	54% 8% 10% 16% 11% 2	2840
	11th to 20th	Night	47% 11% 12% 20% 9% 1	2782
	21st to end	Night	34% 12% 15% 22% 12% 5%	2739
June	1st to 10th	Night	37% 10% 13% 25% 14% 2	1520
	11th to 20th	Night	37% 10% 14% 25% 13% 2	1496
	21st to end	Night	37% 10% 13% 23% 16% 1	1440
July	1st to 10th	Night	38% 9% 13% 20% 16% 4	1400
	11th to 20th	Night	31% 9% 15% 25% 17% 2	1555
	21st to end	Night	38% 9% 16% 21% 14% 3	1672
August	1st to 10th	Night	34% 9% 15% 25% 16% 1	1600
	11th to 20th	Night	36% 9% 13% 26% 13% 2	1598
	21st to end	Night	34% 10% 14% 24% 14% 4	1903
September	1st to 10th	Night	35% 8% 13% 22% 18% 4	1800
	11th to 20th	Night	30% 7% 14% 27% 21% 1	1930
	21st to end	Night	43% 7% 13% 20% 16% 1	2004
October	1st to 10th	Night	41% 8% 13% 23% 13% 2	2160
	11th to 20th	Night	45% 7% 12% 23% 12% 1	2160
	21st to end	Night	52% 7% 12% 18% 10% 1	2376
November	1st to 10th	Night	42% 6% 12% 21% 15% 4	2270
	11th to 20th	Night	54% 6% 11% 18% 9% 2	2651
	21st to end	Night	55% 7% 11% 20% 6% 1	2660
December	1st to 10th	Night	68% 6% 11% 10% 4	2660
	11th to 20th	Night	65% 6% 11% 15% 3	3288
	21st to end	Night	71% 8% 10% 9% 2	4884

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	34% 26% 24% 11% 4 1	238
	11th to 20th	Day	37% 27% 27% 6% 2 1	270
	21st to end	Day	34% 24% 31% 8% 3	297
February	1st to 10th	Day	36% 23% 34% 6% 1	270
	11th to 20th	Day	39% 26% 28% 6% 1	270
	21st to end	Day	38% 28% 27% 6% 1	277
March	1st to 10th	Day	33% 21% 29% 13% 4	460
	11th to 20th	Day	36% 18% 30% 11% 4 1	460
	21st to end	Day	34% 20% 27% 15% 4 1	506
April	1st to 10th	Day	31% 21% 26% 15% 5% 1	460
	11th to 20th	Day	26% 21% 28% 13% 8% 3	452
	21st to end	Day	30% 19% 29% 16% 5% 2	460
May	1st to 10th	Day	31% 14% 27% 18% 7% 3	463
	11th to 20th	Day	25% 13% 30% 17% 11% 4	487
	21st to end	Day	18% 9% 26% 26% 16% 5%	529
June	1st to 10th	Day	18% 13% 27% 25% 13% 3	490
	11th to 20th	Day	20% 14% 24% 26% 13% 4	475
	21st to end	Day	18% 10% 31% 26% 12% 3	450
July	1st to 10th	Day	16% 4 22% 26% 21% 11%	445
	11th to 20th	Day	11% 7% 28% 30% 16% 8%	444
	21st to end	Day	14% 5% 30% 29% 17% 7%	488
August	1st to 10th	Day	13% 6% 23% 27% 22% 9%	446
	11th to 20th	Day	17% 5% 22% 27% 18% 11%	439
	21st to end	Day	13% 6% 25% 27% 18% 10%	495
September	1st to 10th	Day	18% 8% 23% 26% 17% 8%	450
	11th to 20th	Day	13% 4 23% 31% 20% 10%	450
	21st to end	Day	24% 13% 21% 23% 14% 5%	450
October	1st to 10th	Day	20% 13% 24% 21% 19% 4	450
	11th to 20th	Day	27% 16% 27% 22% 8% 1	450
	21st to end	Day	34% 14% 28% 18% 6%	495
November	1st to 10th	Day	20% 17% 29% 20% 11% 3	403
	11th to 20th	Day	31% 23% 27% 13% 5% 2	183
	21st to end	Day	23% 24% 42% 9% 2	180
December	1st to 10th	Day	32% 29% 25% 9% 3 1	180
	11th to 20th	Day	36% 22% 29% 11% 3	180
	21st to end	Day	41% 19% 27% 10% 4	198
January	1st to 10th	Night	29% 22% 31% 14% 4	760
	11th to 20th	Night	34% 18% 31% 15% 3	760
	21st to end	Night	31% 19% 30% 17% 3	836
February	1st to 10th	Night	33% 16% 29% 20% 2	760
	11th to 20th	Night	30% 22% 33% 14% 1	743
	21st to end	Night	31% 17% 32% 18% 2	628
March	1st to 10th	Night	26% 17% 34% 21% 2	760
	11th to 20th	Night	32% 17% 25% 19% 6%	760
	21st to end	Night	26% 16% 34% 20% 4 1	836
April	1st to 10th	Night	28% 15% 30% 21% 5%	760
	11th to 20th	Night	24% 15% 32% 20% 8% 1	751
	21st to end	Night	20% 12% 33% 30% 6%	584
May	1st to 10th	Night	23% 9% 24% 34% 9% 1	570
	11th to 20th	Night	22% 7% 29% 33% 10%	543
	21st to end	Night	11% 5% 25% 34% 22% 3	411
June	1st to 10th	Night	11% 6% 28% 38% 16% 1	380
	11th to 20th	Night	13% 6% 24% 38% 19% 1	374
	21st to end	Night	12% 3 27% 39% 19% 1	360
July	1st to 10th	Night	11% 2 21% 39% 24% 3	350
	11th to 20th	Night	12% 5% 14% 38% 27% 4	511
	21st to end	Night	13% 2 17% 39% 28% 1	591
August	1st to 10th	Night	9% 3 16% 43% 26% 3	537
	11th to 20th	Night	14% 4 12% 38% 28% 4	534
	21st to end	Night	12% 4 19% 33% 28% 4	715
September	1st to 10th	Night	15% 4 21% 33% 25% 3	720
	11th to 20th	Night	12% 4 19% 34% 27% 4	720
	21st to end	Night	20% 8% 22% 27% 19% 4	720
October	1st to 10th	Night	19% 8% 22% 29% 19% 1	720
	11th to 20th	Night	24% 11% 29% 27% 8% 1	720
	21st to end	Night	30% 14% 25% 25% 6%	792
November	1st to 10th	Night	19% 12% 28% 30% 11%	740
	11th to 20th	Night	28% 14% 28% 23% 6% 1	760
	21st to end	Night	28% 15% 31% 20% 6%	760
December	1st to 10th	Night	34% 19% 26% 17% 4	760
	11th to 20th	Night	30% 21% 28% 18% 3	760
	21st to end	Night	31% 19% 28% 21% 2	836

Page generated at 2024-06-14 13:06:15. Version ac07

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