Kinzua Bridge State Park Visitor's Center
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kinzua Bridge State Park Visitor's Center clear sky chart from 2005-11-06 to 2026-08-30.

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	16% 12% 5% 10% 6% 5% 5% 4 5% 6% 28%	144167
	Night	15% 13% 5% 12% 6% 5% 4 3 4 5% 27%	138007
Transparency	Day	55% 5% 11% 19% 10% 1	147763
	Night	57% 5% 11% 17% 9% 1	142498
Seeing	Day	27% 18% 28% 16% 8% 3	16958
	Night	25% 18% 27% 21% 9% 1	26355

By Month

Percentage Cloud Cover NE (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	14% 19% 8% 24% 10% 4 3 2 3 3 10%	4661
	11th to 20th	Day	8% 20% 10% 24% 10% 7% 4 2 3 3 10%	5243
	21st to end	Day	15% 13% 7% 14% 10% 9% 7% 3 4 4 13%	5780
February	1st to 10th	Day	13% 20% 6% 14% 8% 6% 5% 2 4 3 19%	1890
	11th to 20th	Day	13% 16% 8% 16% 8% 5% 4 3 5% 5% 19%	1843
	21st to end	Day	16% 18% 4 13% 7% 4 4 3 4 5% 24%	1668
March	1st to 10th	Day	16% 12% 9% 10% 5% 4 3 3 4 5% 30%	5042
	11th to 20th	Day	12% 15% 7% 10% 4 3 3 3 4 5% 32%	5090
	21st to end	Day	16% 13% 5% 12% 6% 4 4 3 4 4 28%	5586
April	1st to 10th	Day	17% 16% 4 9% 4 4 4 3 5% 6% 27%	2506
	11th to 20th	Day	16% 16% 3 7% 4 4 5% 3 4 5% 31%	2494
	21st to end	Day	21% 11% 3 7% 4 4 3 3 5% 5% 34%	2688
May	1st to 10th	Day	24% 10% 3 8% 5% 5% 5% 4 5% 5% 25%	7642
	11th to 20th	Day	20% 12% 3 8% 5% 4 4 3 5% 7% 28%	8079
	21st to end	Day	20% 9% 3 7% 5% 5% 5% 4 5% 6% 34%	9060
June	1st to 10th	Day	16% 9% 3 6% 6% 5% 5% 3 6% 8% 34%	2940
	11th to 20th	Day	17% 7% 3 7% 5% 6% 5% 4 7% 8% 31%	2940
	21st to end	Day	16% 6% 3 6% 5% 4 4 5% 7% 8% 36%	2940
July	1st to 10th	Day	12% 7% 2 7% 5% 5% 6% 4 6% 9% 37%	8280
	11th to 20th	Day	9% 7% 3 6% 5% 5% 5% 5% 8% 10% 37%	8188
	21st to end	Day	13% 7% 2 7% 5% 4 5% 4 6% 7% 39%	8340
August	1st to 10th	Day	19% 8% 3 8% 5% 5% 5% 4 6% 8% 29%	4364
	11th to 20th	Day	15% 7% 2 8% 6% 6% 7% 5% 7% 9% 27%	4304
	21st to end	Day	13% 7% 2 6% 5% 5% 5% 5% 7% 9% 36%	4469
September	1st to 10th	Day	18% 7% 2 6% 4 4 5% 3 5% 6% 40%	2400
	11th to 20th	Day	14% 6% 3 6% 4 5% 4 4 4 7% 41%	2334
	21st to end	Day	23% 8% 3 7% 5% 3 5% 3 5% 6% 30%	2125
October	1st to 10th	Day	18% 8% 3 7% 4 4 4 4 6% 6% 36%	2000
	11th to 20th	Day	21% 12% 4 8% 5% 3 4 3 5% 5% 31%	2000
	21st to end	Day	22% 15% 3 8% 5% 5% 5% 4 4 5% 25%	2200
November	1st to 10th	Day	14% 14% 4 8% 5% 3 4 4 6% 6% 33%	1917
	11th to 20th	Day	15% 21% 6% 9% 5% 3 3 4 5% 6% 23%	1680
	21st to end	Day	18% 23% 7% 10% 6% 3 4 3 4 4 18%	1680
December	1st to 10th	Day	16% 23% 10% 21% 6% 3 3 2 3 3 9%	2680
	11th to 20th	Day	17% 19% 8% 14% 9% 4 3 2 4 3 17%	3066
	21st to end	Day	18% 24% 9% 13% 5% 4 3 3 3 4 14%	4048
January	1st to 10th	Night	12% 17% 9% 27% 11% 5% 3 2 3 3 8%	8234
	11th to 20th	Night	9% 17% 10% 24% 12% 6% 5% 3 3 3 8%	7639
	21st to end	Night	13% 15% 7% 15% 10% 10% 8% 3 3 3 13%	8401
February	1st to 10th	Night	14% 18% 6% 14% 9% 6% 5% 3 4 3 18%	2730
	11th to 20th	Night	12% 15% 6% 17% 9% 6% 6% 3 4 5% 16%	2663
	21st to end	Night	17% 14% 5% 15% 8% 5% 4 3 4 4 21%	2131
March	1st to 10th	Night	15% 16% 6% 11% 8% 5% 3 2 4 4 26%	5018
	11th to 20th	Night	13% 13% 7% 10% 4 3 3 3 5% 6% 35%	5089
	21st to end	Night	13% 14% 5% 11% 5% 5% 4 3 4 6% 31%	5588
April	1st to 10th	Night	18% 15% 4 10% 5% 4 4 3 5% 5% 27%	2112
	11th to 20th	Night	18% 15% 3 7% 4 3 3 3 6% 5% 34%	2075
	21st to end	Night	15% 12% 3 7% 4 4 4 3 5% 7% 34%	1948
May	1st to 10th	Night	25% 12% 3 6% 4 4 4 3 4 6% 28%	5257
	11th to 20th	Night	20% 15% 3 6% 4 3 4 3 4 5% 34%	4764
	21st to end	Night	21% 10% 3 6% 4 4 4 3 6% 6% 33%	5114
June	1st to 10th	Night	14% 7% 3 6% 5% 5% 4 4 6% 9% 38%	1680
	11th to 20th	Night	12% 8% 3 7% 5% 5% 4 4 6% 8% 38%	1680
	21st to end	Night	14% 8% 2 6% 3 4 4 3 6% 7% 43%	1680
July	1st to 10th	Night	14% 9% 3 7% 4 4 4 3 5% 8% 38%	4680
	11th to 20th	Night	10% 7% 2 7% 4 4 5% 5% 7% 10% 40%	4755
	21st to end	Night	13% 7% 2 6% 4 4 4 3 5% 7% 44%	5737
August	1st to 10th	Night	17% 8% 2 7% 5% 4 5% 4 6% 8% 35%	3005
	11th to 20th	Night	17% 9% 2 7% 4 5% 5% 3 5% 6% 38%	2965
	21st to end	Night	11% 7% 2 6% 4 4 5% 4 5% 9% 44%	3593
September	1st to 10th	Night	14% 7% 3 7% 4 4 4 3 5% 7% 44%	2000
	11th to 20th	Night	13% 6% 2 5% 3 4 4 3 6% 6% 48%	2062
	21st to end	Night	20% 9% 3 7% 5% 5% 5% 4 5% 6% 34%	2275
October	1st to 10th	Night	17% 8% 3 7% 4 4 4 3 4 6% 42%	2400
	11th to 20th	Night	19% 11% 3 6% 5% 4 4 3 5% 6% 33%	2400
	21st to end	Night	22% 14% 4 7% 4 3 4 3 5% 5% 29%	2640
November	1st to 10th	Night	11% 15% 3 8% 4 4 3 3 5% 6% 37%	2594
	11th to 20th	Night	15% 19% 5% 10% 5% 4 4 4 5% 5% 24%	2940
	21st to end	Night	16% 20% 7% 12% 6% 4 4 3 4 5% 20%	2940
December	1st to 10th	Night	13% 19% 10% 20% 8% 5% 5% 3 4 4 10%	4720
	11th to 20th	Night	18% 18% 9% 15% 5% 4 3 2 3 4 18%	5348
	21st to end	Night	18% 20% 9% 14% 7% 4 3 3 4 4 14%	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	80% 3 5% 9% 3	4662
	11th to 20th	Day	81% 2 5% 8% 3	5277
	21st to end	Day	72% 4 9% 11% 4	5780
February	1st to 10th	Day	70% 3 9% 12% 6%	1890
	11th to 20th	Day	67% 4 8% 15% 6%	1852
	21st to end	Day	63% 3 10% 17% 5% 2	1668
March	1st to 10th	Day	56% 4 11% 20% 8%	5045
	11th to 20th	Day	54% 4 15% 18% 7% 2	5090
	21st to end	Day	58% 4 7% 17% 12% 2	5586
April	1st to 10th	Day	58% 4 10% 16% 12% 1	2506
	11th to 20th	Day	53% 6% 10% 17% 12% 1	2494
	21st to end	Day	52% 4 9% 19% 12% 2	2688
May	1st to 10th	Day	58% 6% 10% 18% 7% 2	7651
	11th to 20th	Day	54% 6% 10% 20% 9% 1	8083
	21st to end	Day	50% 5% 10% 21% 13% 1	9061
June	1st to 10th	Day	47% 6% 11% 21% 14% 1	2940
	11th to 20th	Day	48% 7% 14% 20% 11% 1	2940
	21st to end	Day	44% 7% 14% 24% 12%	2940
July	1st to 10th	Day	43% 6% 12% 24% 14% 1	8210
	11th to 20th	Day	39% 7% 14% 28% 12%	8113
	21st to end	Day	42% 6% 11% 26% 15% 1	8156
August	1st to 10th	Day	50% 7% 13% 20% 9% 1	4351
	11th to 20th	Day	48% 8% 16% 23% 5%	4343
	21st to end	Day	41% 6% 12% 30% 10% 1	4469
September	1st to 10th	Day	45% 5% 10% 23% 16% 1	2400
	11th to 20th	Day	42% 5% 11% 25% 15% 1	2334
	21st to end	Day	53% 5% 10% 19% 12%	2125
October	1st to 10th	Day	42% 6% 11% 23% 17% 1	3260
	11th to 20th	Day	47% 4 13% 18% 15% 4	3240
	21st to end	Day	47% 4 13% 24% 10% 1	3538
November	1st to 10th	Day	49% 6% 11% 19% 13% 2	1917
	11th to 20th	Day	60% 4 11% 16% 7% 2	1680
	21st to end	Day	69% 4 10% 12% 4 1	1680
December	1st to 10th	Day	81% 2 8% 7% 2	2680
	11th to 20th	Day	70% 4 9% 13% 3	3066
	21st to end	Day	75% 4 8% 9% 4	4048
January	1st to 10th	Night	81% 3 7% 7% 2	8234
	11th to 20th	Night	80% 3 8% 6% 3	7680
	21st to end	Night	74% 4 7% 10% 4 1	8401
February	1st to 10th	Night	69% 4 9% 12% 6%	2730
	11th to 20th	Night	69% 4 8% 13% 5% 1	2665
	21st to end	Night	66% 4 9% 12% 8% 1	2131
March	1st to 10th	Night	61% 4 12% 16% 6%	5028
	11th to 20th	Night	50% 5% 16% 20% 6% 3	5090
	21st to end	Night	53% 5% 9% 17% 15% 2	5588
April	1st to 10th	Night	58% 5% 9% 16% 11% 1	2112
	11th to 20th	Night	52% 5% 11% 19% 11% 2	2075
	21st to end	Night	49% 5% 12% 21% 12% 2	1948
May	1st to 10th	Night	57% 5% 9% 16% 11% 2	5264
	11th to 20th	Night	52% 5% 12% 20% 9% 1	4765
	21st to end	Night	50% 6% 10% 20% 11% 2	5115
June	1st to 10th	Night	42% 6% 12% 25% 14% 1	1680
	11th to 20th	Night	41% 8% 14% 22% 13% 2	1680
	21st to end	Night	40% 6% 13% 26% 14%	1680
July	1st to 10th	Night	45% 5% 12% 23% 14% 1	4640
	11th to 20th	Night	37% 6% 16% 28% 12% 1	4707
	21st to end	Night	39% 6% 11% 24% 20%	5606
August	1st to 10th	Night	47% 6% 14% 23% 9% 1	2994
	11th to 20th	Night	45% 6% 14% 26% 8%	2992
	21st to end	Night	36% 5% 14% 33% 10% 1	3593
September	1st to 10th	Night	39% 5% 12% 26% 15% 3	2000
	11th to 20th	Night	36% 5% 12% 27% 18% 2	2062
	21st to end	Night	50% 6% 12% 19% 12% 1	2275
October	1st to 10th	Night	43% 5% 9% 22% 19% 1	3920
	11th to 20th	Night	44% 5% 13% 18% 14% 6%	3899
	21st to end	Night	43% 3 15% 24% 13% 1	4252
November	1st to 10th	Night	47% 5% 11% 21% 14% 3	2594
	11th to 20th	Night	61% 5% 9% 15% 7% 2	2940
	21st to end	Night	66% 4 11% 15% 3 1	2940
December	1st to 10th	Night	76% 4 10% 7% 2	4720
	11th to 20th	Night	70% 3 9% 14% 4	5348
	21st to end	Night	74% 4 8% 11% 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% 28% 5% 4	220
	11th to 20th	Day	41% 29% 23% 5% 2	329
	21st to end	Day	40% 24% 29% 6% 1	363
February	1st to 10th	Day	37% 29% 27% 6% 1	330
	11th to 20th	Day	41% 27% 29% 2 1	330
	21st to end	Day	39% 29% 26% 5%	368
March	1st to 10th	Day	34% 25% 29% 9% 2	540
	11th to 20th	Day	36% 25% 28% 9% 2 1	540
	21st to end	Day	37% 25% 25% 10% 3 1	594
April	1st to 10th	Day	35% 23% 26% 12% 3	540
	11th to 20th	Day	33% 24% 24% 11% 6% 2	532
	21st to end	Day	31% 17% 35% 12% 4 1	540
May	1st to 10th	Day	31% 21% 28% 13% 5% 2	543
	11th to 20th	Day	28% 16% 32% 15% 6% 3	567
	21st to end	Day	22% 15% 29% 20% 10% 4	617
June	1st to 10th	Day	21% 17% 30% 22% 8% 2	570
	11th to 20th	Day	24% 16% 26% 22% 10% 2	570
	21st to end	Day	16% 15% 38% 20% 8% 2	570
July	1st to 10th	Day	15% 8% 31% 26% 16% 5%	565
	11th to 20th	Day	15% 11% 30% 24% 16% 5%	564
	21st to end	Day	15% 10% 33% 28% 10% 5%	620
August	1st to 10th	Day	16% 7% 28% 28% 14% 7%	566
	11th to 20th	Day	17% 10% 28% 27% 12% 6%	559
	21st to end	Day	14% 12% 31% 23% 14% 6%	619
September	1st to 10th	Day	23% 12% 22% 22% 15% 8%	530
	11th to 20th	Day	15% 6% 24% 25% 20% 9%	530
	21st to end	Day	30% 11% 26% 18% 11% 4	530
October	1st to 10th	Day	20% 13% 29% 19% 15% 4	530
	11th to 20th	Day	28% 22% 29% 13% 6% 1	530
	21st to end	Day	33% 19% 29% 16% 3	583
November	1st to 10th	Day	28% 21% 27% 15% 7% 2	447
	11th to 20th	Day	39% 23% 27% 9% 1 2	220
	21st to end	Day	38% 24% 32% 5% 1	220
December	1st to 10th	Day	40% 31% 21% 5% 2 1	220
	11th to 20th	Day	45% 21% 28% 5% 1	220
	21st to end	Day	38% 26% 30% 4 2	242
January	1st to 10th	Night	29% 29% 31% 8% 2	840
	11th to 20th	Night	32% 28% 25% 13% 2	840
	21st to end	Night	29% 30% 27% 13% 1	924
February	1st to 10th	Night	31% 25% 29% 15%	840
	11th to 20th	Night	29% 30% 30% 9% 1	823
	21st to end	Night	32% 28% 29% 10% 1	692
March	1st to 10th	Night	27% 27% 30% 14% 2	840
	11th to 20th	Night	31% 23% 25% 16% 3 1	840
	21st to end	Night	27% 22% 33% 14% 4 1	924
April	1st to 10th	Night	29% 21% 30% 16% 3	840
	11th to 20th	Night	29% 18% 28% 17% 7% 1	831
	21st to end	Night	23% 14% 32% 26% 5%	688
May	1st to 10th	Night	25% 10% 28% 27% 9%	630
	11th to 20th	Night	21% 12% 29% 33% 6%	463
	21st to end	Night	18% 9% 25% 30% 16% 2	455
June	1st to 10th	Night	14% 9% 31% 33% 12%	420
	11th to 20th	Night	14% 12% 26% 37% 10%	420
	21st to end	Night	15% 7% 30% 33% 14%	420
July	1st to 10th	Night	15% 4 25% 35% 19% 2	410
	11th to 20th	Night	10% 6% 22% 39% 23% 1	431
	21st to end	Night	14% 5% 20% 39% 21% 1	690
August	1st to 10th	Night	13% 4 21% 35% 25% 2	627
	11th to 20th	Night	17% 5% 16% 35% 23% 3	624
	21st to end	Night	14% 6% 22% 33% 22% 3	859
September	1st to 10th	Night	17% 8% 23% 28% 20% 3	800
	11th to 20th	Night	15% 7% 19% 29% 27% 4	800
	21st to end	Night	23% 11% 22% 23% 17% 4	800
October	1st to 10th	Night	22% 11% 26% 23% 17% 2	800
	11th to 20th	Night	26% 16% 31% 20% 7% 1	800
	21st to end	Night	32% 14% 33% 17% 4	880
November	1st to 10th	Night	22% 18% 32% 21% 6%	820
	11th to 20th	Night	30% 20% 29% 14% 5% 2	840
	21st to end	Night	31% 22% 29% 13% 3	840
December	1st to 10th	Night	35% 27% 24% 10% 4	840
	11th to 20th	Night	33% 26% 25% 14% 3	840
	21st to end	Night	32% 24% 30% 13% 1	924

Page generated at 2026-08-27 04:07:16. Version ac07

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