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 2025-01-07.

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% 10% 3 8% 5% 5% 5% 4 6% 7% 33%	104585
	Night	14% 11% 4 8% 5% 4 4 4 5% 7% 34%	104440
Transparency	Day	48% 6% 13% 21% 11% 1	108201
	Night	48% 5% 13% 21% 11% 1	108965
Seeing	Day	17% 11% 29% 24% 13% 5%	15471
	Night	19% 10% 30% 29% 12% 1	25102

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	14% 19% 7% 11% 5% 5% 4 4 4 4 23%	2575
	11th to 20th	Day	15% 19% 6% 13% 9% 6% 4 3 5% 6% 14%	2534
	21st to end	Day	24% 20% 7% 9% 6% 4 4 3 3 4 16%	3124
February	1st to 10th	Day	14% 15% 5% 14% 8% 6% 4 4 5% 5% 21%	1710
	11th to 20th	Day	13% 13% 5% 12% 8% 4 4 5% 5% 5% 26%	1746
	21st to end	Day	13% 16% 5% 11% 6% 5% 5% 3 5% 4 26%	1570
March	1st to 10th	Day	17% 16% 6% 10% 6% 4 3 2 4 5% 28%	3240
	11th to 20th	Day	12% 14% 5% 9% 6% 4 5% 4 5% 6% 30%	3480
	21st to end	Day	18% 13% 3 9% 5% 5% 5% 3 5% 6% 28%	3815
April	1st to 10th	Day	15% 15% 4 8% 6% 3 4 3 6% 7% 30%	2175
	11th to 20th	Day	17% 10% 3 7% 5% 4 4 4 5% 7% 35%	2442
	21st to end	Day	17% 10% 3 7% 5% 5% 4 4 5% 6% 34%	2470
May	1st to 10th	Day	16% 8% 3 8% 5% 4 4 4 6% 7% 35%	4082
	11th to 20th	Day	16% 8% 3 7% 5% 4 5% 4 6% 8% 34%	4081
	21st to end	Day	10% 6% 2 6% 4 4 4 4 5% 7% 47%	4568
June	1st to 10th	Day	10% 6% 2 7% 6% 4 4 4 7% 9% 40%	2812
	11th to 20th	Day	10% 6% 2 5% 5% 4 6% 5% 7% 8% 42%	2850
	21st to end	Day	10% 6% 2 8% 4 5% 5% 5% 7% 9% 39%	2850
July	1st to 10th	Day	10% 6% 2 7% 5% 5% 7% 5% 8% 9% 37%	4484
	11th to 20th	Day	8% 5% 2 5% 4 4 5% 5% 7% 10% 45%	4440
	21st to end	Day	7% 5% 2 7% 4 6% 6% 4 8% 10% 41%	4498
August	1st to 10th	Day	13% 6% 2 6% 5% 5% 6% 5% 6% 9% 39%	4104
	11th to 20th	Day	9% 6% 2 6% 5% 5% 6% 6% 8% 9% 37%	4044
	21st to end	Day	9% 5% 2 7% 6% 5% 6% 5% 7% 8% 39%	4532
September	1st to 10th	Day	9% 7% 2 6% 5% 5% 6% 4 6% 8% 41%	2156
	11th to 20th	Day	10% 5% 2 6% 4 5% 4 3 6% 8% 47%	2090
	21st to end	Day	16% 7% 2 7% 5% 4 5% 4 7% 9% 34%	2090
October	1st to 10th	Day	13% 7% 3 7% 6% 4 4 4 6% 7% 41%	2005
	11th to 20th	Day	18% 10% 3 7% 5% 5% 4 3 5% 7% 33%	1900
	21st to end	Day	20% 10% 3 8% 5% 4 4 3 5% 7% 30%	1966
November	1st to 10th	Day	13% 10% 2 8% 7% 4 4 3 6% 8% 34%	1762
	11th to 20th	Day	13% 11% 4 11% 6% 5% 4 4 5% 6% 30%	1773
	21st to end	Day	17% 13% 5% 9% 6% 5% 4 4 6% 5% 26%	1600
December	1st to 10th	Day	14% 14% 5% 11% 7% 4 5% 4 7% 7% 23%	2600
	11th to 20th	Day	18% 22% 4 8% 4 5% 4 4 5% 5% 22%	2803
	21st to end	Day	25% 21% 7% 11% 5% 4 3 3 4 4 14%	3614
January	1st to 10th	Night	16% 15% 6% 11% 5% 4 4 3 5% 6% 26%	4513
	11th to 20th	Night	14% 17% 7% 14% 7% 7% 5% 3 5% 5% 17%	4433
	21st to end	Night	22% 17% 8% 10% 5% 4 3 2 4 5% 19%	4532
February	1st to 10th	Night	15% 16% 5% 12% 7% 5% 5% 3 5% 5% 23%	2470
	11th to 20th	Night	13% 13% 6% 10% 7% 4 4 5% 5% 6% 28%	2318
	21st to end	Night	17% 12% 4 11% 7% 5% 5% 4 5% 5% 27%	1884
March	1st to 10th	Night	15% 14% 5% 8% 4 4 4 2 4 5% 35%	3612
	11th to 20th	Night	9% 9% 3 7% 5% 4 5% 4 6% 8% 38%	3480
	21st to end	Night	16% 10% 3 7% 4 4 4 3 4 5% 39%	3817
April	1st to 10th	Night	18% 11% 3 6% 4 4 4 3 5% 7% 35%	2019
	11th to 20th	Night	19% 8% 3 6% 5% 4 4 3 6% 7% 37%	1687
	21st to end	Night	17% 9% 2 6% 5% 4 4 4 6% 8% 36%	1710
May	1st to 10th	Night	16% 9% 3 7% 4 4 4 4 6% 7% 37%	2813
	11th to 20th	Night	13% 7% 3 7% 5% 5% 5% 3 5% 7% 40%	2812
	21st to end	Night	11% 5% 2 4 4 4 4 4 5% 8% 50%	2984
June	1st to 10th	Night	11% 6% 2 6% 3 3 4 4 6% 9% 45%	1363
	11th to 20th	Night	8% 7% 2 6% 3 4 6% 4 6% 10% 44%	1330
	21st to end	Night	9% 5% 2 6% 4 4 5% 4 5% 9% 48%	1330
July	1st to 10th	Night	7% 4 2 5% 4 4 4 4 6% 11% 49%	2481
	11th to 20th	Night	9% 4 1 5% 3 4 4 4 5% 9% 52%	2530
	21st to end	Night	5% 4 1 5% 4 5% 6% 5% 7% 9% 48%	3052
August	1st to 10th	Night	11% 6% 2 6% 4 4 4 3 6% 8% 47%	2825
	11th to 20th	Night	10% 7% 3 6% 4 4 5% 4 6% 7% 46%	2785
	21st to end	Night	7% 6% 2 6% 5% 5% 5% 4 5% 7% 47%	3124
September	1st to 10th	Night	10% 6% 2 6% 5% 5% 5% 4 5% 6% 47%	2002
	11th to 20th	Night	10% 4 2 4 3 3 4 4 5% 6% 54%	2090
	21st to end	Night	15% 6% 2 7% 5% 4 4 4 5% 7% 43%	2090
October	1st to 10th	Night	15% 6% 2 7% 4 3 3 3 5% 7% 45%	2175
	11th to 20th	Night	19% 8% 3 7% 5% 4 4 3 6% 6% 35%	2280
	21st to end	Night	21% 9% 3 7% 4 5% 4 4 5% 6% 31%	2631
November	1st to 10th	Night	13% 9% 3 6% 3 4 5% 4 5% 7% 42%	2536
	11th to 20th	Night	15% 12% 3 8% 5% 5% 6% 4 6% 7% 29%	2625
	21st to end	Night	18% 14% 4 8% 5% 4 4 4 5% 7% 27%	2800
December	1st to 10th	Night	12% 15% 6% 11% 6% 5% 5% 4 6% 7% 24%	4580
	11th to 20th	Night	14% 18% 5% 11% 6% 4 4 3 5% 5% 23%	5381
	21st to end	Night	23% 20% 6% 10% 5% 5% 3 3 4 5% 16%	7346

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	65% 5% 12% 13% 4 1	2576
	11th to 20th	Day	70% 7% 12% 8% 3	2534
	21st to end	Day	72% 4 13% 7% 3	3124
February	1st to 10th	Day	65% 5% 11% 13% 6%	1710
	11th to 20th	Day	58% 5% 11% 16% 8% 1	1755
	21st to end	Day	60% 4 12% 14% 7% 2	1570
March	1st to 10th	Day	58% 5% 13% 18% 6%	3240
	11th to 20th	Day	51% 6% 13% 20% 8% 2	3480
	21st to end	Day	54% 6% 14% 14% 9% 2	3815
April	1st to 10th	Day	52% 6% 12% 19% 11% 1	2175
	11th to 20th	Day	47% 6% 11% 20% 14% 2	2442
	21st to end	Day	50% 7% 13% 16% 12% 2	2470
May	1st to 10th	Day	44% 8% 13% 20% 12% 3	4120
	11th to 20th	Day	46% 7% 16% 21% 9% 1	4085
	21st to end	Day	36% 6% 12% 18% 23% 5%	4582
June	1st to 10th	Day	38% 7% 14% 25% 14% 2	2812
	11th to 20th	Day	36% 7% 13% 24% 16% 2	2850
	21st to end	Day	39% 7% 14% 24% 15% 1	2850
July	1st to 10th	Day	41% 5% 15% 21% 16% 2	4415
	11th to 20th	Day	32% 5% 13% 35% 13% 1	4365
	21st to end	Day	36% 6% 17% 21% 19% 2	4356
August	1st to 10th	Day	41% 6% 14% 23% 15% 1	4091
	11th to 20th	Day	40% 7% 13% 30% 9% 1	4083
	21st to end	Day	40% 5% 13% 30% 11% 1	4531
September	1st to 10th	Day	38% 9% 14% 25% 12% 2	2156
	11th to 20th	Day	34% 6% 14% 32% 13% 1	2090
	21st to end	Day	44% 6% 15% 23% 10% 1	2090
October	1st to 10th	Day	34% 4 10% 34% 16% 2	3330
	11th to 20th	Day	43% 4 11% 25% 17%	3140
	21st to end	Day	47% 4 14% 22% 12%	3216
November	1st to 10th	Day	47% 7% 12% 23% 10% 1	1762
	11th to 20th	Day	54% 5% 14% 17% 10% 1	1773
	21st to end	Day	58% 6% 13% 17% 5% 1	1600
December	1st to 10th	Day	59% 5% 19% 13% 5%	2600
	11th to 20th	Day	64% 3 13% 12% 8%	2799
	21st to end	Day	75% 4 8% 8% 5%	3614
January	1st to 10th	Night	59% 5% 14% 15% 6% 1	4513
	11th to 20th	Night	68% 6% 13% 10% 3	4433
	21st to end	Night	69% 4 10% 15% 3	4532
February	1st to 10th	Night	62% 7% 10% 14% 7% 1	2470
	11th to 20th	Night	55% 6% 11% 17% 10% 1	2320
	21st to end	Night	58% 5% 12% 17% 7% 1	1884
March	1st to 10th	Night	51% 5% 14% 24% 6%	3612
	11th to 20th	Night	39% 7% 17% 22% 14% 1	3480
	21st to end	Night	47% 6% 11% 24% 12% 1	3817
April	1st to 10th	Night	49% 5% 11% 21% 12% 2	2019
	11th to 20th	Night	45% 6% 11% 19% 18% 2	1687
	21st to end	Night	44% 7% 12% 19% 15% 4	1710
May	1st to 10th	Night	44% 7% 12% 20% 13% 4	2840
	11th to 20th	Night	42% 7% 14% 24% 11% 2	2813
	21st to end	Night	32% 7% 12% 22% 19% 8%	2991
June	1st to 10th	Night	35% 7% 12% 28% 17% 2	1363
	11th to 20th	Night	34% 7% 15% 22% 19% 2	1330
	21st to end	Night	33% 6% 15% 25% 19% 2	1330
July	1st to 10th	Night	31% 3 14% 30% 16% 6%	2441
	11th to 20th	Night	29% 4 13% 35% 17% 1	2482
	21st to end	Night	30% 7% 19% 21% 21% 3	2955
August	1st to 10th	Night	36% 4 15% 28% 16% 2	2814
	11th to 20th	Night	36% 5% 15% 30% 11% 2	2812
	21st to end	Night	36% 5% 13% 31% 15% 1	3124
September	1st to 10th	Night	36% 6% 14% 28% 14% 2	2002
	11th to 20th	Night	30% 6% 14% 31% 20% 1	2090
	21st to end	Night	41% 6% 12% 28% 12% 1	2090
October	1st to 10th	Night	27% 4 10% 32% 26% 1	3630
	11th to 20th	Night	44% 3 11% 24% 16%	3779
	21st to end	Night	43% 4 13% 27% 12% 1	4331
November	1st to 10th	Night	41% 6% 13% 26% 12% 1	2536
	11th to 20th	Night	52% 6% 14% 18% 9% 1	2625
	21st to end	Night	56% 5% 15% 17% 6%	2800
December	1st to 10th	Night	59% 5% 19% 14% 3	4580
	11th to 20th	Night	62% 4 11% 14% 8% 1	5384
	21st to end	Night	71% 4 11% 10% 5%	7346

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% 18% 38% 18% 4 1	288
	11th to 20th	Day	21% 17% 42% 16% 2 1	270
	21st to end	Day	26% 16% 34% 19% 4 1	297
February	1st to 10th	Day	21% 19% 42% 13% 4 1	270
	11th to 20th	Day	23% 17% 39% 20% 1	270
	21st to end	Day	19% 28% 38% 14% 2	225
March	1st to 10th	Day	25% 18% 36% 17% 4 1	338
	11th to 20th	Day	19% 15% 35% 22% 7% 1	460
	21st to end	Day	26% 12% 33% 22% 6% 1	506
April	1st to 10th	Day	17% 18% 35% 22% 7% 1	460
	11th to 20th	Day	26% 16% 27% 16% 10% 5%	452
	21st to end	Day	21% 12% 29% 26% 10% 3	460
May	1st to 10th	Day	18% 14% 30% 23% 13% 3	463
	11th to 20th	Day	20% 7% 29% 23% 16% 6%	487
	21st to end	Day	13% 8% 21% 31% 19% 8%	529
June	1st to 10th	Day	12% 8% 30% 31% 14% 5%	642
	11th to 20th	Day	11% 8% 32% 30% 14% 5%	680
	21st to end	Day	12% 8% 29% 32% 15% 5%	680
July	1st to 10th	Day	7% 7% 22% 31% 21% 12%	671
	11th to 20th	Day	10% 5% 27% 31% 17% 8%	668
	21st to end	Day	7% 3 23% 34% 24% 10%	551
August	1st to 10th	Day	10% 4 18% 28% 26% 14%	486
	11th to 20th	Day	12% 4 19% 30% 22% 14%	479
	21st to end	Day	13% 5% 20% 28% 22% 12%	539
September	1st to 10th	Day	13% 5% 25% 23% 22% 11%	490
	11th to 20th	Day	9% 5% 18% 24% 29% 14%	490
	21st to end	Day	18% 8% 25% 23% 18% 8%	490
October	1st to 10th	Day	15% 9% 28% 23% 18% 7%	490
	11th to 20th	Day	19% 15% 34% 24% 7% 1	490
	21st to end	Day	25% 13% 36% 18% 6% 1	415
November	1st to 10th	Day	18% 17% 36% 19% 9% 1	300
	11th to 20th	Day	22% 21% 33% 17% 6% 1	285
	21st to end	Day	26% 18% 41% 13% 4	200
December	1st to 10th	Day	23% 21% 33% 18% 5% 1	200
	11th to 20th	Day	27% 20% 35% 16% 2 1	200
	21st to end	Day	31% 17% 32% 17% 3	250
January	1st to 10th	Night	23% 15% 37% 19% 5% 1	981
	11th to 20th	Night	24% 17% 33% 22% 4 1	943
	21st to end	Night	20% 11% 36% 27% 6%	836
February	1st to 10th	Night	23% 13% 40% 22% 3	760
	11th to 20th	Night	21% 14% 34% 26% 5%	743
	21st to end	Night	23% 14% 40% 21% 3	628
March	1st to 10th	Night	20% 12% 36% 26% 6%	760
	11th to 20th	Night	15% 13% 38% 27% 6% 1	760
	21st to end	Night	23% 9% 32% 28% 7% 1	836
April	1st to 10th	Night	22% 14% 34% 25% 4 1	694
	11th to 20th	Night	20% 9% 33% 25% 10% 2	563
	21st to end	Night	20% 6% 33% 31% 9% 1	570
May	1st to 10th	Night	18% 6% 30% 33% 12% 1	570
	11th to 20th	Night	17% 5% 28% 36% 13% 1	561
	21st to end	Night	12% 4 24% 36% 23% 1	560
June	1st to 10th	Night	14% 3 26% 42% 16%	380
	11th to 20th	Night	12% 4 25% 43% 15% 1	380
	21st to end	Night	10% 3 24% 45% 17% 1	380
July	1st to 10th	Night	8% 2 15% 43% 29% 4	519
	11th to 20th	Night	11% 2 17% 40% 26% 4	552
	21st to end	Night	6% 2 20% 44% 25% 2	624
August	1st to 10th	Night	8% 3 16% 39% 32% 3	567
	11th to 20th	Night	7% 1 17% 37% 34% 3	564
	21st to end	Night	10% 4 18% 35% 29% 4	627
September	1st to 10th	Night	11% 5% 22% 33% 24% 5%	708
	11th to 20th	Night	11% 4 19% 35% 26% 6%	760
	21st to end	Night	17% 6% 21% 34% 18% 4	760
October	1st to 10th	Night	15% 9% 27% 30% 17% 2	760
	11th to 20th	Night	23% 13% 29% 26% 9% 1	760
	21st to end	Night	24% 12% 33% 26% 4	836
November	1st to 10th	Night	18% 12% 32% 26% 12% 1	780
	11th to 20th	Night	22% 14% 35% 22% 7% 1	800
	21st to end	Night	26% 14% 33% 22% 6%	800
December	1st to 10th	Night	22% 14% 40% 18% 5%	800
	11th to 20th	Night	24% 15% 37% 21% 3	880
	21st to end	Night	31% 12% 33% 22% 2	1100

Page generated at 2025-01-04 03:24:04. Version ac07

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