Kenockee Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kenockee Observatory clear sky chart from 2005-11-06 to 2024-01-17.

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	14% 9% 4 7% 6% 3 5% 5% 6% 7% 34%	74681
	Night	15% 10% 4 7% 6% 3 5% 5% 5% 7% 35%	75150
Transparency	Day	48% 7% 13% 20% 11% 1	74392
	Night	49% 6% 13% 20% 11% 1	74961
Seeing	Day	17% 11% 29% 24% 14% 6%	14162
	Night	19% 9% 30% 29% 12% 1	23840

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	15% 14% 6% 11% 7% 4 5% 4 4 5% 24%	1517
	11th to 20th	Day	14% 16% 8% 11% 10% 4 5% 4 5% 6% 17%	1492
	21st to end	Day	15% 16% 9% 10% 9% 4 5% 4 4 4 19%	1782
February	1st to 10th	Day	16% 14% 5% 13% 10% 4 5% 4 4 5% 20%	1620
	11th to 20th	Day	15% 11% 6% 11% 9% 3 5% 5% 5% 5% 25%	1652
	21st to end	Day	14% 16% 6% 10% 8% 4 5% 4 4 4 26%	1480
March	1st to 10th	Day	15% 11% 5% 9% 8% 3 5% 3 4 6% 28%	1864
	11th to 20th	Day	12% 14% 5% 7% 7% 3 5% 5% 5% 7% 32%	1980
	21st to end	Day	19% 13% 4 8% 6% 4 5% 5% 4 6% 26%	2178
April	1st to 10th	Day	15% 13% 5% 7% 6% 2 4 4 6% 7% 29%	2059
	11th to 20th	Day	16% 9% 4 6% 6% 3 4 5% 5% 7% 34%	2312
	21st to end	Day	18% 9% 4 6% 6% 3 5% 5% 5% 6% 33%	2340
May	1st to 10th	Day	16% 7% 4 7% 7% 3 5% 5% 5% 7% 33%	2340
	11th to 20th	Day	19% 8% 3 5% 5% 3 4 5% 5% 6% 37%	2301
	21st to end	Day	13% 5% 3 5% 5% 3 5% 5% 6% 8% 41%	2582
June	1st to 10th	Day	10% 5% 3 6% 6% 3 5% 5% 7% 9% 41%	2664
	11th to 20th	Day	11% 6% 2 5% 5% 3 6% 5% 7% 8% 43%	2700
	21st to end	Day	10% 6% 2 6% 6% 3 5% 6% 6% 9% 41%	2700
July	1st to 10th	Day	6% 5% 2 4 5% 3 5% 6% 7% 9% 47%	2550
	11th to 20th	Day	9% 5% 3 5% 5% 3 5% 6% 7% 10% 43%	2520
	21st to end	Day	9% 5% 2 5% 5% 4 6% 5% 7% 10% 41%	2565
August	1st to 10th	Day	10% 5% 2 5% 5% 4 6% 7% 7% 10% 39%	2327
	11th to 20th	Day	9% 6% 2 5% 7% 4 6% 6% 7% 9% 39%	2303
	21st to end	Day	12% 5% 2 6% 6% 3 6% 6% 6% 8% 42%	2574
September	1st to 10th	Day	10% 7% 2 6% 6% 4 6% 6% 7% 8% 39%	2044
	11th to 20th	Day	11% 5% 2 5% 5% 4 5% 4 6% 8% 46%	1980
	21st to end	Day	16% 6% 2 6% 5% 3 5% 5% 7% 9% 35%	1980
October	1st to 10th	Day	13% 7% 3 6% 7% 3 5% 4 5% 7% 40%	1900
	11th to 20th	Day	18% 9% 4 6% 7% 4 4 4 5% 7% 32%	1800
	21st to end	Day	21% 10% 3 7% 6% 3 4 4 5% 7% 29%	1863
November	1st to 10th	Day	13% 9% 3 7% 8% 3 4 5% 6% 8% 34%	1672
	11th to 20th	Day	13% 10% 4 10% 7% 4 5% 5% 5% 6% 31%	1685
	21st to end	Day	18% 12% 6% 8% 7% 3 4 4 6% 6% 27%	1520
December	1st to 10th	Day	13% 13% 6% 10% 10% 4 6% 5% 5% 6% 22%	1520
	11th to 20th	Day	17% 15% 6% 7% 6% 4 4 5% 5% 7% 25%	1788
	21st to end	Day	27% 19% 7% 8% 6% 3 3 4 4 5% 12%	2527
January	1st to 10th	Night	18% 11% 6% 9% 7% 4 5% 4 5% 6% 25%	2648
	11th to 20th	Night	18% 16% 7% 10% 7% 4 5% 4 4 5% 21%	2610
	21st to end	Night	13% 14% 8% 10% 8% 4 5% 4 5% 6% 23%	2574
February	1st to 10th	Night	16% 16% 6% 10% 8% 4 6% 4 4 5% 22%	2340
	11th to 20th	Night	14% 13% 6% 9% 7% 4 4 5% 5% 6% 27%	2192
	21st to end	Night	18% 11% 4 9% 8% 4 5% 4 4 5% 27%	1776
March	1st to 10th	Night	15% 11% 5% 7% 6% 4 5% 4 5% 5% 33%	2095
	11th to 20th	Night	12% 8% 4 6% 6% 4 5% 5% 5% 8% 37%	1980
	21st to end	Night	19% 10% 4 6% 6% 3 4 4 5% 4 34%	2178
April	1st to 10th	Night	18% 9% 4 6% 5% 3 4 4 5% 7% 35%	1914
	11th to 20th	Night	18% 7% 3 5% 6% 3 3 4 5% 8% 38%	1597
	21st to end	Night	17% 8% 3 5% 5% 3 3 5% 6% 8% 36%	1620
May	1st to 10th	Night	16% 8% 3 6% 6% 4 5% 5% 6% 7% 34%	1620
	11th to 20th	Night	17% 5% 3 5% 5% 3 5% 4 5% 7% 41%	1592
	21st to end	Night	11% 4 2 4 4 3 5% 5% 6% 8% 48%	1690
June	1st to 10th	Night	11% 5% 2 6% 3 2 5% 5% 6% 10% 46%	1292
	11th to 20th	Night	9% 6% 2 5% 4 3 5% 6% 6% 10% 45%	1260
	21st to end	Night	9% 5% 2 5% 5% 3 5% 4 6% 9% 49%	1260
July	1st to 10th	Night	7% 4 2 4 4 3 4 4 5% 9% 55%	1405
	11th to 20th	Night	8% 5% 2 4 4 2 4 5% 6% 10% 50%	1440
	21st to end	Night	6% 4 2 4 4 4 5% 5% 7% 9% 50%	1749
August	1st to 10th	Night	8% 4 2 5% 4 3 4 5% 7% 11% 48%	1611
	11th to 20th	Night	7% 3 2 5% 5% 4 5% 5% 7% 9% 49%	1598
	21st to end	Night	9% 5% 2 4 4 3 5% 4 5% 8% 51%	1782
September	1st to 10th	Night	10% 5% 3 6% 5% 3 5% 4 5% 7% 46%	1895
	11th to 20th	Night	10% 4 2 4 4 2 4 5% 5% 7% 52%	1980
	21st to end	Night	14% 6% 2 6% 5% 2 4 4 5% 7% 44%	1980
October	1st to 10th	Night	15% 6% 2 6% 4 3 4 4 5% 7% 44%	2060
	11th to 20th	Night	19% 8% 3 6% 6% 3 5% 4 6% 6% 35%	2160
	21st to end	Night	22% 9% 3 6% 6% 4 4 5% 5% 6% 30%	2492
November	1st to 10th	Night	13% 8% 3 6% 4 3 5% 4 5% 7% 42%	2406
	11th to 20th	Night	16% 10% 4 7% 6% 4 5% 5% 6% 7% 30%	2493
	21st to end	Night	19% 13% 4 7% 6% 3 4 5% 4 7% 29%	2660
December	1st to 10th	Night	16% 14% 6% 9% 7% 4 5% 5% 5% 6% 23%	2660
	11th to 20th	Night	14% 13% 6% 10% 7% 3 5% 5% 5% 6% 25%	3405
	21st to end	Night	27% 20% 6% 8% 6% 3 3 4 4 4 15%	5136

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	63% 5% 11% 14% 6% 1	1518
	11th to 20th	Day	68% 7% 12% 9% 5%	1492
	21st to end	Day	68% 4 9% 13% 6% 1	1782
February	1st to 10th	Day	67% 4 10% 12% 5%	1620
	11th to 20th	Day	59% 5% 11% 16% 7% 1	1661
	21st to end	Day	61% 4 11% 14% 8% 2	1480
March	1st to 10th	Day	57% 5% 13% 15% 9% 1	1864
	11th to 20th	Day	51% 6% 11% 17% 12% 3	1980
	21st to end	Day	57% 6% 10% 18% 7% 1	2178
April	1st to 10th	Day	53% 6% 12% 19% 10% 1	2059
	11th to 20th	Day	48% 6% 12% 18% 14% 2	2312
	21st to end	Day	50% 7% 14% 15% 12% 2	2340
May	1st to 10th	Day	49% 6% 11% 21% 11% 2	2340
	11th to 20th	Day	47% 6% 11% 20% 13% 2	2305
	21st to end	Day	40% 8% 13% 23% 15% 2	2582
June	1st to 10th	Day	38% 7% 14% 25% 14% 2	2664
	11th to 20th	Day	37% 8% 13% 24% 16% 2	2700
	21st to end	Day	38% 8% 14% 25% 15% 1	2700
July	1st to 10th	Day	31% 8% 13% 27% 19% 3	2481
	11th to 20th	Day	34% 7% 15% 27% 16% 2	2445
	21st to end	Day	35% 8% 15% 23% 16% 3	2423
August	1st to 10th	Day	37% 10% 16% 24% 12% 1	2314
	11th to 20th	Day	38% 10% 14% 25% 12% 2	2303
	21st to end	Day	38% 8% 12% 28% 13% 1	2574
September	1st to 10th	Day	40% 9% 15% 22% 12% 2	2044
	11th to 20th	Day	35% 6% 15% 33% 11% 1	1980
	21st to end	Day	43% 6% 16% 24% 10% 1	1980
October	1st to 10th	Day	44% 6% 11% 25% 13% 1	1900
	11th to 20th	Day	51% 6% 13% 21% 9% 1	1800
	21st to end	Day	55% 6% 14% 17% 8%	1863
November	1st to 10th	Day	46% 8% 12% 23% 10% 1	1672
	11th to 20th	Day	53% 5% 15% 17% 10% 1	1685
	21st to end	Day	57% 6% 13% 18% 6% 1	1520
December	1st to 10th	Day	61% 7% 14% 14% 4	1520
	11th to 20th	Day	59% 5% 16% 15% 5%	1784
	21st to end	Day	74% 5% 11% 7% 2	2527
January	1st to 10th	Night	60% 5% 12% 16% 7% 1	2648
	11th to 20th	Night	66% 5% 12% 11% 5%	2610
	21st to end	Night	61% 6% 12% 17% 5%	2574
February	1st to 10th	Night	64% 6% 10% 13% 7% 1	2340
	11th to 20th	Night	57% 5% 11% 16% 10% 1	2194
	21st to end	Night	58% 5% 11% 17% 8% 1	1776
March	1st to 10th	Night	53% 5% 11% 21% 8% 1	2095
	11th to 20th	Night	44% 6% 12% 24% 12% 2	1980
	21st to end	Night	52% 6% 9% 22% 11% 1	2178
April	1st to 10th	Night	49% 5% 11% 21% 12% 2	1914
	11th to 20th	Night	44% 6% 11% 19% 18% 2	1597
	21st to end	Night	44% 7% 11% 19% 15% 4	1620
May	1st to 10th	Night	47% 7% 10% 21% 11% 3	1620
	11th to 20th	Night	42% 6% 10% 20% 17% 4	1593
	21st to end	Night	33% 9% 14% 25% 16% 4	1691
June	1st to 10th	Night	34% 7% 12% 28% 17% 2	1292
	11th to 20th	Night	33% 7% 15% 23% 19% 2	1260
	21st to end	Night	33% 6% 14% 26% 20% 2	1260
July	1st to 10th	Night	28% 5% 12% 29% 23% 4	1365
	11th to 20th	Night	29% 6% 15% 32% 16% 2	1392
	21st to end	Night	28% 9% 19% 22% 18% 3	1652
August	1st to 10th	Night	29% 8% 17% 31% 13% 2	1600
	11th to 20th	Night	29% 8% 18% 31% 12% 3	1598
	21st to end	Night	32% 7% 14% 29% 17% 1	1782
September	1st to 10th	Night	37% 6% 14% 27% 13% 2	1895
	11th to 20th	Night	31% 6% 14% 31% 18% 1	1980
	21st to end	Night	39% 6% 13% 29% 12% 1	1980
October	1st to 10th	Night	39% 7% 12% 25% 17% 1	2060
	11th to 20th	Night	49% 6% 13% 21% 10% 1	2160
	21st to end	Night	54% 6% 11% 19% 9% 1	2492
November	1st to 10th	Night	40% 6% 14% 26% 13% 1	2406
	11th to 20th	Night	52% 6% 15% 18% 8% 1	2493
	21st to end	Night	55% 6% 16% 17% 6%	2660
December	1st to 10th	Night	61% 7% 14% 15% 4	2660
	11th to 20th	Night	58% 6% 14% 15% 6%	3408
	21st to end	Night	73% 5% 11% 7% 3	5136

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% 17% 37% 19% 4 1	270
	11th to 20th	Day	23% 15% 43% 16% 2 1	258
	21st to end	Day	23% 17% 36% 18% 5% 1	264
February	1st to 10th	Day	23% 19% 43% 12% 3	240
	11th to 20th	Day	25% 17% 40% 18% 1	240
	21st to end	Day	20% 29% 36% 14% 2	198
March	1st to 10th	Day	25% 17% 38% 15% 4 1	304
	11th to 20th	Day	19% 15% 35% 22% 8% 1	420
	21st to end	Day	27% 11% 32% 23% 6% 1	462
April	1st to 10th	Day	17% 17% 35% 22% 8% 1	420
	11th to 20th	Day	25% 15% 27% 17% 10% 6%	412
	21st to end	Day	23% 11% 29% 25% 10% 3	420
May	1st to 10th	Day	18% 13% 31% 22% 13% 3	423
	11th to 20th	Day	21% 8% 29% 22% 15% 6%	447
	21st to end	Day	14% 7% 20% 31% 19% 8%	485
June	1st to 10th	Day	12% 7% 30% 32% 14% 5%	594
	11th to 20th	Day	11% 8% 31% 30% 15% 5%	630
	21st to end	Day	11% 6% 29% 33% 15% 5%	630
July	1st to 10th	Day	7% 6% 20% 32% 22% 13%	621
	11th to 20th	Day	11% 5% 26% 32% 18% 8%	618
	21st to end	Day	8% 3 23% 32% 25% 10%	506
August	1st to 10th	Day	10% 3 17% 28% 26% 15%	446
	11th to 20th	Day	11% 3 17% 31% 23% 14%	439
	21st to end	Day	14% 6% 20% 26% 22% 12%	495
September	1st to 10th	Day	14% 4 24% 24% 23% 11%	450
	11th to 20th	Day	10% 6% 19% 23% 29% 14%	450
	21st to end	Day	17% 8% 24% 24% 19% 9%	450
October	1st to 10th	Day	15% 9% 27% 24% 18% 7%	450
	11th to 20th	Day	19% 16% 34% 24% 7%	450
	21st to end	Day	25% 13% 38% 18% 6% 1	378
November	1st to 10th	Day	17% 17% 36% 20% 10% 1	270
	11th to 20th	Day	19% 21% 33% 18% 7% 2	257
	21st to end	Day	24% 17% 41% 13% 4	180
December	1st to 10th	Day	22% 21% 33% 17% 6% 1	180
	11th to 20th	Day	25% 21% 36% 15% 2 1	180
	21st to end	Day	29% 17% 33% 17% 3	225
January	1st to 10th	Night	23% 14% 37% 20% 5% 1	950
	11th to 20th	Night	24% 17% 33% 22% 4 1	928
	21st to end	Night	19% 11% 36% 27% 7%	792
February	1st to 10th	Night	23% 13% 41% 21% 2	720
	11th to 20th	Night	22% 14% 33% 25% 5%	703
	21st to end	Night	24% 13% 39% 20% 3	592
March	1st to 10th	Night	20% 12% 36% 27% 5%	720
	11th to 20th	Night	16% 12% 37% 27% 7% 1	720
	21st to end	Night	24% 9% 31% 29% 7% 1	792
April	1st to 10th	Night	22% 13% 34% 26% 4 1	658
	11th to 20th	Night	20% 9% 33% 26% 11% 2	533
	21st to end	Night	20% 5% 34% 31% 9% 1	540
May	1st to 10th	Night	18% 6% 30% 33% 11% 1	540
	11th to 20th	Night	17% 5% 28% 36% 13% 1	531
	21st to end	Night	12% 4 23% 36% 24% 1	530
June	1st to 10th	Night	14% 3 25% 42% 16%	360
	11th to 20th	Night	12% 4 24% 43% 16% 1	360
	21st to end	Night	10% 3 23% 47% 17% 1	360
July	1st to 10th	Night	8% 2 14% 42% 30% 4	490
	11th to 20th	Night	12% 2 16% 41% 25% 4	522
	21st to end	Night	6% 2 21% 45% 24% 2	591
August	1st to 10th	Night	8% 2 15% 39% 33% 3	537
	11th to 20th	Night	7% 1 17% 37% 34% 3	534
	21st to end	Night	10% 4 18% 34% 29% 4	594
September	1st to 10th	Night	11% 4 22% 34% 24% 5%	670
	11th to 20th	Night	12% 4 20% 35% 25% 5%	720
	21st to end	Night	16% 6% 21% 34% 19% 4	720
October	1st to 10th	Night	16% 8% 26% 30% 18% 2	720
	11th to 20th	Night	23% 13% 29% 27% 8% 1	720
	21st to end	Night	25% 12% 33% 25% 5%	792
November	1st to 10th	Night	18% 11% 32% 26% 12% 1	740
	11th to 20th	Night	21% 14% 36% 22% 7% 1	760
	21st to end	Night	25% 12% 34% 22% 6%	760
December	1st to 10th	Night	22% 14% 40% 18% 5%	760
	11th to 20th	Night	23% 15% 37% 21% 3	836
	21st to end	Night	30% 12% 33% 22% 2	1045

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