Stoutsville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Stoutsville clear sky chart from 2005-11-06 to 2025-07-21.

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	12% 8% 3 7% 4 4 4 4 5% 7% 42%	120337
	Night	12% 8% 3 7% 4 4 4 3 5% 7% 43%	119040
Transparency	Day	40% 4 12% 24% 17% 2	123978
	Night	41% 3 11% 24% 18% 3	123542
Seeing	Day	15% 7% 26% 28% 18% 6%	16676
	Night	16% 8% 30% 31% 14% 1	26500

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	12% 12% 5% 13% 6% 5% 4 3 5% 6% 30%	3617
	11th to 20th	Day	9% 10% 4 8% 5% 7% 6% 3 5% 6% 38%	4057
	21st to end	Day	15% 14% 6% 11% 5% 3 3 2 3 5% 33%	4488
February	1st to 10th	Day	15% 11% 4 8% 5% 5% 4 4 4 7% 33%	1800
	11th to 20th	Day	14% 11% 3 8% 4 5% 5% 3 5% 6% 37%	1819
	21st to end	Day	14% 12% 4 5% 4 3 4 4 5% 6% 40%	1650
March	1st to 10th	Day	16% 10% 3 5% 3 3 2 2 3 5% 48%	4789
	11th to 20th	Day	8% 6% 2 6% 4 4 3 4 5% 7% 51%	4980
	21st to end	Day	14% 11% 3 7% 5% 5% 4 4 6% 7% 33%	5598
April	1st to 10th	Day	14% 9% 3 7% 5% 4 5% 3 4 6% 41%	2400
	11th to 20th	Day	15% 8% 2 8% 4 4 4 4 5% 6% 40%	2374
	21st to end	Day	18% 8% 3 7% 4 4 4 4 6% 7% 35%	2400
May	1st to 10th	Day	12% 8% 3 8% 5% 5% 5% 5% 7% 9% 34%	5716
	11th to 20th	Day	14% 7% 3 7% 4 4 4 3 5% 7% 42%	6290
	21st to end	Day	15% 7% 3 7% 5% 4 4 3 5% 7% 41%	6935
June	1st to 10th	Day	7% 4 2 6% 4 5% 5% 5% 6% 9% 48%	2800
	11th to 20th	Day	8% 5% 2 5% 5% 4 5% 4 6% 10% 47%	2800
	21st to end	Day	7% 5% 2 6% 5% 5% 5% 5% 6% 10% 46%	2800
July	1st to 10th	Day	12% 6% 3 6% 5% 5% 5% 5% 7% 9% 39%	4580
	11th to 20th	Day	5% 4 2 6% 4 4 5% 4 7% 10% 49%	4557
	21st to end	Day	7% 5% 2 6% 5% 6% 6% 5% 7% 11% 39%	4466
August	1st to 10th	Day	4 4 2 5% 4 5% 5% 4 7% 11% 49%	4104
	11th to 20th	Day	13% 6% 2 5% 3 4 4 4 5% 9% 46%	3889
	21st to end	Day	6% 4 2 5% 4 4 5% 4 6% 9% 52%	4180
September	1st to 10th	Day	10% 5% 2 5% 3 4 4 3 5% 7% 52%	2280
	11th to 20th	Day	10% 4 2 5% 4 4 3 2 5% 7% 54%	2280
	21st to end	Day	8% 5% 2 5% 4 3 3 4 6% 8% 51%	2010
October	1st to 10th	Day	11% 4 2 6% 3 4 3 3 5% 5% 54%	1900
	11th to 20th	Day	14% 6% 2 5% 4 2 3 3 5% 6% 51%	1900
	21st to end	Day	17% 8% 2 6% 4 3 3 3 4 6% 45%	2090
November	1st to 10th	Day	11% 7% 2 5% 2 3 3 3 4 6% 52%	1810
	11th to 20th	Day	15% 7% 2 6% 3 3 3 3 5% 6% 45%	1778
	21st to end	Day	16% 11% 3 8% 4 3 4 3 4 5% 40%	1600
December	1st to 10th	Day	7% 8% 4 7% 4 3 4 2 4 6% 51%	2610
	11th to 20th	Day	13% 8% 4 10% 5% 4 4 4 6% 6% 38%	3008
	21st to end	Day	20% 20% 5% 11% 4 4 4 3 4 5% 19%	3982
January	1st to 10th	Night	14% 11% 7% 13% 6% 4 4 3 4 4 30%	6348
	11th to 20th	Night	12% 12% 4 11% 5% 5% 5% 4 5% 5% 32%	5919
	21st to end	Night	15% 14% 5% 10% 4 4 3 3 4 6% 33%	6490
February	1st to 10th	Night	14% 12% 4 7% 6% 4 4 4 4 6% 35%	2600
	11th to 20th	Night	15% 10% 3 7% 4 4 4 3 4 6% 40%	2467
	21st to end	Night	14% 8% 3 7% 4 3 3 2 5% 4 46%	1980
March	1st to 10th	Night	18% 11% 3 6% 3 3 3 2 3 4 44%	5107
	11th to 20th	Night	11% 7% 2 5% 3 3 4 3 4 5% 52%	4980
	21st to end	Night	15% 10% 4 8% 6% 4 4 4 5% 7% 34%	5330
April	1st to 10th	Night	12% 6% 3 6% 3 4 4 4 5% 7% 45%	2000
	11th to 20th	Night	13% 7% 2 6% 4 4 4 3 4 7% 46%	1975
	21st to end	Night	17% 7% 3 7% 4 4 5% 3 4 6% 40%	2000
May	1st to 10th	Night	15% 8% 3 7% 4 4 4 4 5% 8% 36%	4191
	11th to 20th	Night	12% 6% 2 7% 4 4 5% 3 6% 8% 44%	3624
	21st to end	Night	13% 6% 2 6% 4 3 3 4 6% 8% 44%	3942
June	1st to 10th	Night	7% 4 2 4 4 4 4 4 7% 8% 54%	1600
	11th to 20th	Night	6% 5% 2 6% 5% 5% 4 3 6% 10% 49%	1600
	21st to end	Night	4 3 2 6% 3 4 4 4 7% 10% 53%	1600
July	1st to 10th	Night	10% 7% 3 6% 4 4 4 4 6% 9% 43%	2610
	11th to 20th	Night	4 3 2 4 3 3 4 4 6% 9% 58%	2629
	21st to end	Night	6% 5% 2 5% 4 4 5% 5% 7% 11% 43%	3098
August	1st to 10th	Night	4 2 1 3 3 4 4 4 6% 10% 60%	2836
	11th to 20th	Night	10% 5% 2 5% 3 4 4 3 5% 7% 51%	2942
	21st to end	Night	3 3 2 5% 3 4 4 3 7% 10% 57%	3476
September	1st to 10th	Night	10% 5% 1 3 3 3 3 3 4 7% 58%	1900
	11th to 20th	Night	8% 6% 2 5% 3 3 5% 3 6% 8% 51%	1900
	21st to end	Night	7% 5% 2 5% 4 4 4 3 5% 6% 54%	2148
October	1st to 10th	Night	9% 5% 2 4 2 2 4 3 5% 7% 57%	2280
	11th to 20th	Night	12% 5% 2 5% 4 3 3 3 4 5% 54%	2280
	21st to end	Night	16% 8% 2 5% 4 4 3 3 5% 5% 46%	2508
November	1st to 10th	Night	11% 6% 2 5% 3 3 3 2 4 7% 55%	2485
	11th to 20th	Night	13% 6% 2 7% 4 4 3 2 5% 6% 47%	2620
	21st to end	Night	16% 9% 3 6% 3 3 3 3 5% 5% 43%	2800
December	1st to 10th	Night	9% 8% 3 8% 5% 3 4 3 4 6% 48%	4580
	11th to 20th	Night	14% 9% 4 7% 3 3 3 4 6% 7% 40%	5199
	21st to end	Night	23% 17% 6% 10% 5% 4 3 3 3 4 21%	6996

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	56% 4 9% 19% 10% 2	3618
	11th to 20th	Day	48% 2 12% 18% 14% 5%	4057
	21st to end	Day	56% 3 9% 15% 15% 2	4488
February	1st to 10th	Day	52% 3 12% 20% 10% 2	1800
	11th to 20th	Day	48% 4 11% 20% 15% 2	1828
	21st to end	Day	45% 4 9% 24% 15% 3	1650
March	1st to 10th	Day	41% 3 8% 24% 23% 2	4789
	11th to 20th	Day	33% 4 10% 27% 22% 4	4980
	21st to end	Day	50% 3 17% 23% 6% 1	5600
April	1st to 10th	Day	44% 4 11% 26% 14% 1	2400
	11th to 20th	Day	44% 3 10% 26% 14% 2	2374
	21st to end	Day	46% 5% 14% 21% 13% 1	2400
May	1st to 10th	Day	44% 5% 15% 22% 14%	5752
	11th to 20th	Day	43% 4 10% 27% 14% 2	6294
	21st to end	Day	43% 5% 9% 24% 19% 1	6949
June	1st to 10th	Day	32% 5% 16% 30% 15% 2	2800
	11th to 20th	Day	32% 5% 13% 26% 20% 4	2800
	21st to end	Day	33% 6% 16% 26% 16% 3	2800
July	1st to 10th	Day	41% 4 12% 25% 15% 2	4511
	11th to 20th	Day	30% 4 16% 29% 19% 2	4482
	21st to end	Day	37% 4 18% 27% 12% 1	4326
August	1st to 10th	Day	28% 5% 15% 38% 13% 1	4090
	11th to 20th	Day	37% 4 13% 28% 18% 1	3928
	21st to end	Day	28% 4 17% 32% 14% 5%	4179
September	1st to 10th	Day	32% 3 11% 25% 22% 6%	2280
	11th to 20th	Day	31% 4 9% 30% 21% 5%	2280
	21st to end	Day	31% 5% 10% 27% 24% 3	2010
October	1st to 10th	Day	21% 2 6% 18% 45% 8%	3160
	11th to 20th	Day	24% 2 6% 22% 37% 10%	3140
	21st to end	Day	39% 3 7% 23% 26% 2	3428
November	1st to 10th	Day	35% 3 12% 24% 21% 5%	1810
	11th to 20th	Day	39% 4 10% 23% 20% 4	1778
	21st to end	Day	47% 4 9% 26% 13% 1	1600
December	1st to 10th	Day	36% 3 17% 28% 16%	2610
	11th to 20th	Day	48% 3 13% 24% 12% 1	3005
	21st to end	Day	68% 3 11% 12% 5%	3982
January	1st to 10th	Night	59% 3 9% 21% 8% 1	6348
	11th to 20th	Night	54% 4 8% 19% 13% 2	5919
	21st to end	Night	55% 2 8% 19% 14% 2	6490
February	1st to 10th	Night	52% 3 11% 20% 11% 2	2600
	11th to 20th	Night	46% 4 10% 23% 15% 2	2468
	21st to end	Night	43% 3 10% 25% 16% 4	1980
March	1st to 10th	Night	45% 3 6% 22% 22% 2	5107
	11th to 20th	Night	36% 3 6% 27% 24% 5%	4980
	21st to end	Night	50% 4 12% 24% 8% 2	5330
April	1st to 10th	Night	38% 4 11% 26% 18% 4	2000
	11th to 20th	Night	40% 3 10% 25% 18% 5%	1975
	21st to end	Night	46% 5% 10% 21% 17% 1	2000
May	1st to 10th	Night	46% 5% 14% 21% 13% 1	4220
	11th to 20th	Night	39% 5% 12% 27% 13% 4	3625
	21st to end	Night	39% 4 11% 22% 21% 2	3950
June	1st to 10th	Night	27% 5% 17% 31% 18% 3	1600
	11th to 20th	Night	31% 5% 12% 25% 23% 4	1600
	21st to end	Night	25% 5% 17% 28% 19% 6%	1600
July	1st to 10th	Night	38% 4 12% 29% 14% 3	2570
	11th to 20th	Night	24% 3 12% 35% 24% 2	2581
	21st to end	Night	33% 5% 19% 28% 14% 1	2999
August	1st to 10th	Night	20% 3 18% 38% 19% 2	2826
	11th to 20th	Night	34% 3 12% 28% 21% 2	2969
	21st to end	Night	23% 4 20% 33% 15% 4	3476
September	1st to 10th	Night	28% 3 11% 25% 26% 8%	1900
	11th to 20th	Night	30% 5% 10% 26% 23% 6%	1900
	21st to end	Night	30% 4 8% 28% 26% 4	2148
October	1st to 10th	Night	18% 2 7% 21% 47% 5%	3800
	11th to 20th	Night	24% 2 7% 22% 34% 10%	3779
	21st to end	Night	38% 2 6% 24% 26% 3	4120
November	1st to 10th	Night	31% 4 12% 28% 21% 5%	2485
	11th to 20th	Night	38% 3 8% 26% 21% 3	2620
	21st to end	Night	44% 3 10% 26% 15% 1	2800
December	1st to 10th	Night	39% 3 10% 35% 12% 1	4580
	11th to 20th	Night	44% 3 13% 23% 16% 1	5201
	21st to end	Night	68% 3 12% 12% 5% 1	6996

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	21% 13% 35% 24% 7%	300
	11th to 20th	Day	25% 14% 41% 20% 1	300
	21st to end	Day	17% 14% 42% 22% 6%	330
February	1st to 10th	Day	27% 10% 42% 16% 5%	300
	11th to 20th	Day	22% 15% 37% 19% 6%	300
	21st to end	Day	20% 14% 43% 18% 5%	249
March	1st to 10th	Day	17% 14% 43% 24% 2	300
	11th to 20th	Day	24% 13% 31% 23% 8% 1	300
	21st to end	Day	30% 13% 29% 23% 5% 1	389
April	1st to 10th	Day	20% 14% 36% 20% 9% 1	500
	11th to 20th	Day	20% 13% 33% 25% 8% 2	492
	21st to end	Day	23% 7% 36% 25% 9% 1	500
May	1st to 10th	Day	17% 8% 33% 28% 11% 3	633
	11th to 20th	Day	18% 8% 24% 29% 17% 4	725
	21st to end	Day	14% 4 28% 29% 17% 7%	789
June	1st to 10th	Day	7% 3 18% 35% 25% 10%	730
	11th to 20th	Day	10% 2 20% 36% 27% 6%	730
	21st to end	Day	8% 3 26% 35% 23% 5%	730
July	1st to 10th	Day	11% 2 12% 31% 31% 13%	721
	11th to 20th	Day	8% 2 17% 36% 28% 10%	718
	21st to end	Day	10% 1 13% 32% 34% 9%	740
August	1st to 10th	Day	8% 2 13% 38% 31% 9%	676
	11th to 20th	Day	10% 2 16% 30% 32% 10%	578
	21st to end	Day	9% 1 11% 32% 33% 14%	539
September	1st to 10th	Day	12% 3 13% 30% 29% 13%	490
	11th to 20th	Day	7% 2 13% 35% 27% 15%	490
	21st to end	Day	10% 5% 23% 28% 23% 10%	367
October	1st to 10th	Day	12% 4 24% 33% 17% 9%	300
	11th to 20th	Day	14% 17% 31% 25% 13% 1	300
	21st to end	Day	26% 12% 33% 21% 8%	330
November	1st to 10th	Day	12% 7% 35% 31% 12% 3	300
	11th to 20th	Day	19% 15% 31% 23% 10% 1	300
	21st to end	Day	25% 13% 32% 23% 6% 1	300
December	1st to 10th	Day	13% 12% 43% 19% 8% 4	300
	11th to 20th	Day	19% 14% 35% 24% 7%	300
	21st to end	Day	27% 16% 36% 18% 2	330
January	1st to 10th	Night	17% 12% 42% 24% 5%	1000
	11th to 20th	Night	18% 16% 38% 23% 5%	1000
	21st to end	Night	18% 10% 42% 27% 3	1100
February	1st to 10th	Night	20% 12% 39% 26% 4	1000
	11th to 20th	Night	21% 14% 35% 27% 3	913
	21st to end	Night	21% 14% 40% 21% 3	660
March	1st to 10th	Night	19% 12% 39% 27% 4	690
	11th to 20th	Night	21% 10% 33% 28% 8%	600
	21st to end	Night	26% 10% 32% 26% 6%	660
April	1st to 10th	Night	16% 12% 38% 28% 6%	600
	11th to 20th	Night	16% 10% 35% 30% 9% 1	593
	21st to end	Night	23% 6% 33% 32% 7%	600
May	1st to 10th	Night	18% 5% 30% 35% 11% 1	600
	11th to 20th	Night	17% 4 24% 36% 17% 1	591
	21st to end	Night	12% 3 25% 35% 22% 3	650
June	1st to 10th	Night	9% 2 18% 42% 28% 2	600
	11th to 20th	Night	9% 2 19% 42% 27% 2	600
	21st to end	Night	5% 3 21% 47% 23% 2	600
July	1st to 10th	Night	9% 1 10% 34% 39% 6%	585
	11th to 20th	Night	9% 1 13% 41% 31% 4	582
	21st to end	Night	8% 1 10% 41% 37% 4	624
August	1st to 10th	Night	8% 1 9% 41% 38% 3	567
	11th to 20th	Night	9% 2 11% 42% 32% 5%	564
	21st to end	Night	6% 1 10% 39% 41% 3	627
September	1st to 10th	Night	12% 2 15% 36% 30% 5%	570
	11th to 20th	Night	12% 2 17% 36% 28% 5%	570
	21st to end	Night	11% 5% 22% 34% 22% 5%	698
October	1st to 10th	Night	11% 4 25% 34% 22% 4	760
	11th to 20th	Night	15% 9% 33% 31% 12% 1	760
	21st to end	Night	21% 9% 35% 27% 8%	836
November	1st to 10th	Night	14% 8% 37% 32% 9%	780
	11th to 20th	Night	16% 13% 39% 26% 6%	820
	21st to end	Night	23% 10% 37% 24% 6%	1000
December	1st to 10th	Night	19% 11% 39% 25% 6%	1000
	11th to 20th	Night	23% 9% 34% 28% 7%	1000
	21st to end	Night	24% 13% 35% 25% 3	1100

Page generated at 2025-07-18 00:10:02. Version ac07

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