Wakely Mountain
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wakely Mountain clear sky chart from 2005-11-06 to 2026-06-16.

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% 13% 5% 11% 6% 5% 5% 3 5% 6% 26%	137883
	Night	15% 14% 6% 13% 7% 5% 4 3 4 5% 24%	134140
Transparency	Day	55% 8% 10% 17% 9% 1	141350
	Night	58% 8% 10% 14% 8% 1	138762
Seeing	Day	27% 21% 29% 15% 6% 2	16680
	Night	24% 21% 28% 20% 8% 1	25786

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	7% 16% 9% 22% 14% 7% 4 2 2 3 13%	4661
	11th to 20th	Day	7% 16% 8% 25% 14% 9% 3 1 2 2 13%	4650
	21st to end	Day	8% 15% 7% 17% 8% 9% 9% 4 4 4 16%	5322
February	1st to 10th	Day	10% 17% 8% 14% 10% 6% 5% 4 4 4 17%	1890
	11th to 20th	Day	8% 14% 8% 18% 11% 5% 4 3 3 4 20%	1953
	21st to end	Day	13% 17% 7% 15% 6% 7% 4 3 5% 5% 19%	1730
March	1st to 10th	Day	15% 17% 7% 18% 6% 3 4 2 3 3 21%	4576
	11th to 20th	Day	11% 17% 9% 11% 6% 4 4 2 4 6% 27%	4920
	21st to end	Day	16% 15% 7% 12% 6% 3 3 2 3 4 29%	6022
April	1st to 10th	Day	17% 19% 5% 10% 4 3 3 3 4 4 28%	2520
	11th to 20th	Day	17% 16% 5% 8% 4 4 4 3 4 5% 31%	2494
	21st to end	Day	20% 16% 3 7% 5% 4 4 3 4 5% 28%	2601
May	1st to 10th	Day	28% 15% 4 8% 4 4 4 3 4 5% 21%	8071
	11th to 20th	Day	18% 14% 3 8% 5% 5% 5% 4 5% 6% 27%	8221
	21st to end	Day	22% 12% 3 8% 5% 5% 5% 4 5% 6% 27%	9060
June	1st to 10th	Day	22% 8% 3 8% 6% 6% 5% 3 5% 6% 28%	2940
	11th to 20th	Day	20% 9% 2 7% 4 5% 5% 5% 6% 7% 28%	2870
	21st to end	Day	21% 9% 3 8% 5% 5% 4 4 5% 7% 28%	2800
July	1st to 10th	Day	13% 7% 2 7% 5% 5% 5% 5% 7% 10% 33%	6360
	11th to 20th	Day	12% 9% 3 7% 5% 5% 6% 5% 7% 9% 33%	6360
	21st to end	Day	15% 7% 2 6% 5% 5% 5% 4 6% 8% 37%	6926
August	1st to 10th	Day	18% 9% 3 6% 4 5% 5% 4 7% 7% 32%	4534
	11th to 20th	Day	17% 10% 4 8% 5% 5% 6% 5% 6% 8% 27%	3949
	21st to end	Day	16% 8% 2 7% 4 5% 5% 4 6% 8% 34%	4312
September	1st to 10th	Day	16% 7% 2 6% 4 5% 5% 3 5% 8% 38%	2400
	11th to 20th	Day	15% 8% 2 6% 4 4 4 3 5% 6% 44%	2344
	21st to end	Day	19% 8% 3 6% 5% 4 4 4 6% 7% 34%	2200
October	1st to 10th	Day	24% 12% 2 6% 4 4 5% 3 4 4 31%	2029
	11th to 20th	Day	18% 15% 4 7% 4 4 4 4 6% 6% 28%	2000
	21st to end	Day	23% 18% 4 8% 4 4 4 3 4 4 23%	2006
November	1st to 10th	Day	13% 19% 5% 9% 5% 4 4 3 4 5% 27%	1851
	11th to 20th	Day	12% 18% 7% 10% 6% 4 4 3 4 4 26%	1837
	21st to end	Day	15% 19% 7% 13% 5% 5% 4 3 4 5% 20%	1680
December	1st to 10th	Day	11% 25% 9% 23% 9% 4 3 2 3 2 11%	2680
	11th to 20th	Day	14% 18% 8% 20% 8% 4 3 3 4 3 15%	3066
	21st to end	Day	14% 18% 8% 15% 6% 5% 3 3 4 5% 20%	4048
January	1st to 10th	Night	10% 15% 10% 23% 10% 9% 4 3 3 3 12%	8234
	11th to 20th	Night	7% 16% 10% 26% 17% 8% 3 2 2 2 7%	8235
	21st to end	Night	9% 11% 6% 19% 10% 11% 11% 4 4 4 11%	8842
February	1st to 10th	Night	10% 16% 7% 18% 12% 7% 4 3 4 3 15%	2730
	11th to 20th	Night	9% 12% 7% 18% 12% 7% 5% 4 5% 5% 16%	2552
	21st to end	Night	11% 16% 6% 15% 9% 7% 3 4 4 6% 19%	2076
March	1st to 10th	Night	15% 14% 5% 14% 9% 6% 6% 3 4 4 19%	5484
	11th to 20th	Night	12% 15% 7% 11% 5% 3 3 3 4 6% 29%	5241
	21st to end	Night	18% 14% 8% 16% 6% 3 3 2 3 4 23%	5151
April	1st to 10th	Night	17% 16% 6% 10% 6% 4 3 3 4 5% 26%	2100
	11th to 20th	Night	18% 17% 5% 7% 4 4 3 3 4 6% 29%	2075
	21st to end	Night	19% 14% 4 8% 4 3 4 3 4 6% 32%	2017
May	1st to 10th	Night	27% 18% 4 7% 3 3 4 3 4 5% 21%	4882
	11th to 20th	Night	19% 16% 3 7% 4 4 4 4 5% 6% 30%	4639
	21st to end	Night	20% 13% 3 7% 5% 4 5% 3 5% 6% 28%	5114
June	1st to 10th	Night	22% 7% 3 5% 4 4 5% 4 4 7% 35%	1680
	11th to 20th	Night	21% 8% 2 5% 4 4 5% 3 6% 7% 36%	1640
	21st to end	Night	20% 8% 3 6% 4 4 3 4 6% 8% 34%	1600
July	1st to 10th	Night	13% 9% 3 7% 5% 5% 4 4 6% 9% 36%	3600
	11th to 20th	Night	17% 9% 3 6% 4 4 5% 3 5% 6% 38%	3600
	21st to end	Night	11% 10% 3 6% 4 3 4 3 5% 8% 44%	3926
August	1st to 10th	Night	21% 11% 3 6% 3 3 4 3 4 5% 38%	2612
	11th to 20th	Night	19% 13% 3 6% 4 3 3 3 4 6% 34%	3065
	21st to end	Night	11% 14% 2 5% 3 3 5% 4 5% 7% 40%	3586
September	1st to 10th	Night	14% 8% 3 6% 4 4 4 3 5% 6% 42%	2000
	11th to 20th	Night	13% 8% 3 6% 4 3 4 4 4 5% 47%	2055
	21st to end	Night	18% 10% 3 6% 3 3 4 3 5% 6% 38%	2200
October	1st to 10th	Night	20% 13% 3 7% 4 5% 4 3 4 5% 31%	2369
	11th to 20th	Night	17% 14% 3 7% 5% 4 5% 4 5% 6% 30%	2400
	21st to end	Night	21% 20% 4 8% 4 4 4 3 4 4 23%	2832
November	1st to 10th	Night	14% 17% 6% 9% 5% 4 5% 3 5% 5% 27%	2667
	11th to 20th	Night	13% 17% 6% 12% 5% 5% 4 4 4 5% 24%	2778
	21st to end	Night	13% 18% 8% 14% 6% 5% 4 4 4 5% 18%	2940
December	1st to 10th	Night	13% 22% 11% 26% 7% 3 3 2 3 3 9%	4720
	11th to 20th	Night	16% 18% 11% 17% 8% 4 3 2 3 3 15%	5348
	21st to end	Night	15% 19% 6% 17% 6% 5% 4 3 3 4 17%	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	71% 12% 6% 8% 4	4662
	11th to 20th	Day	76% 6% 4 4 7% 3	4680
	21st to end	Day	64% 11% 8% 10% 5% 1	5322
February	1st to 10th	Day	68% 7% 8% 12% 4 1	1890
	11th to 20th	Day	66% 6% 8% 11% 8% 1	1962
	21st to end	Day	64% 8% 9% 11% 8% 1	1730
March	1st to 10th	Day	65% 7% 7% 8% 9% 3	4579
	11th to 20th	Day	58% 6% 13% 12% 8% 3	4920
	21st to end	Day	57% 7% 6% 12% 16% 2	6022
April	1st to 10th	Day	59% 5% 8% 15% 10% 2	2520
	11th to 20th	Day	55% 6% 8% 18% 12% 1	2494
	21st to end	Day	57% 5% 10% 14% 11% 3	2601
May	1st to 10th	Day	62% 8% 7% 13% 9% 1	8083
	11th to 20th	Day	54% 9% 11% 19% 7%	8225
	21st to end	Day	54% 8% 10% 21% 6%	9061
June	1st to 10th	Day	54% 8% 12% 15% 10% 1	2940
	11th to 20th	Day	50% 9% 12% 19% 9% 1	2870
	21st to end	Day	53% 8% 13% 17% 8% 1	2800
July	1st to 10th	Day	42% 9% 16% 23% 10%	6290
	11th to 20th	Day	42% 10% 13% 24% 10%	6285
	21st to end	Day	42% 8% 12% 32% 6%	6728
August	1st to 10th	Day	46% 9% 15% 19% 10%	4520
	11th to 20th	Day	49% 11% 16% 20% 5%	3988
	21st to end	Day	43% 9% 15% 25% 8%	4312
September	1st to 10th	Day	42% 7% 13% 27% 10% 1	2400
	11th to 20th	Day	40% 6% 10% 26% 16% 1	2344
	21st to end	Day	46% 8% 13% 20% 12% 1	2200
October	1st to 10th	Day	50% 6% 10% 22% 11% 1	3302
	11th to 20th	Day	48% 6% 13% 15% 15% 3	3240
	21st to end	Day	48% 7% 14% 23% 7% 1	3218
November	1st to 10th	Day	57% 8% 11% 15% 10%	1851
	11th to 20th	Day	58% 7% 10% 13% 10% 2	1837
	21st to end	Day	65% 8% 12% 10% 5% 1	1680
December	1st to 10th	Day	79% 5% 6% 8% 2	2680
	11th to 20th	Day	69% 9% 7% 10% 5%	3066
	21st to end	Day	65% 6% 6% 8% 13% 2	4048
January	1st to 10th	Night	71% 11% 6% 7% 4	8234
	11th to 20th	Night	79% 8% 5% 3 3 1	8280
	21st to end	Night	68% 12% 7% 7% 5% 1	8842
February	1st to 10th	Night	70% 7% 8% 9% 5% 1	2730
	11th to 20th	Night	65% 8% 9% 11% 7% 1	2554
	21st to end	Night	61% 8% 10% 12% 8% 1	2076
March	1st to 10th	Night	62% 10% 9% 9% 8% 2	5494
	11th to 20th	Night	53% 8% 15% 15% 7% 3	5242
	21st to end	Night	62% 7% 5% 14% 11% 1	5151
April	1st to 10th	Night	59% 6% 10% 15% 9% 1	2100
	11th to 20th	Night	54% 8% 10% 17% 11%	2075
	21st to end	Night	52% 7% 10% 17% 12% 2	2017
May	1st to 10th	Night	62% 8% 8% 11% 10% 1	4888
	11th to 20th	Night	51% 9% 11% 20% 8% 1	4640
	21st to end	Night	52% 9% 10% 19% 8% 1	5115
June	1st to 10th	Night	48% 7% 14% 21% 10% 1	1680
	11th to 20th	Night	47% 7% 14% 20% 10% 1	1640
	21st to end	Night	46% 8% 14% 22% 9%	1600
July	1st to 10th	Night	42% 9% 17% 19% 11% 1	3560
	11th to 20th	Night	42% 10% 13% 23% 12%	3552
	21st to end	Night	36% 8% 15% 32% 8% 1	3809
August	1st to 10th	Night	48% 7% 15% 22% 8%	2602
	11th to 20th	Night	47% 9% 15% 22% 7%	3092
	21st to end	Night	38% 10% 14% 29% 8% 1	3586
September	1st to 10th	Night	39% 9% 14% 27% 10% 1	2000
	11th to 20th	Night	36% 6% 14% 30% 13% 1	2055
	21st to end	Night	44% 7% 12% 22% 13% 2	2200
October	1st to 10th	Night	52% 9% 10% 19% 10% 1	3876
	11th to 20th	Night	48% 7% 12% 18% 10% 6%	3899
	21st to end	Night	53% 8% 12% 20% 7% 1	4570
November	1st to 10th	Night	57% 8% 11% 14% 9% 2	2667
	11th to 20th	Night	58% 7% 10% 14% 8% 3	2778
	21st to end	Night	64% 9% 10% 11% 5% 1	2940
December	1st to 10th	Night	79% 6% 6% 5% 2	4720
	11th to 20th	Night	72% 6% 6% 8% 7%	5348
	21st to end	Night	69% 7% 6% 6% 9% 4	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	29% 28% 31% 8% 5%	220
	11th to 20th	Day	32% 30% 30% 5% 1 1	220
	21st to end	Day	29% 31% 28% 9% 3	278
February	1st to 10th	Day	36% 34% 26% 4	330
	11th to 20th	Day	35% 29% 29% 5% 1	440
	21st to end	Day	36% 26% 29% 8% 1	446
March	1st to 10th	Day	31% 27% 28% 11% 3	540
	11th to 20th	Day	33% 27% 25% 11% 3 1	540
	21st to end	Day	35% 27% 22% 11% 4 1	594
April	1st to 10th	Day	39% 25% 22% 8% 5% 1	540
	11th to 20th	Day	34% 25% 21% 13% 4 2	532
	21st to end	Day	34% 21% 28% 10% 5% 2	540
May	1st to 10th	Day	36% 21% 26% 9% 5% 3	543
	11th to 20th	Day	24% 20% 31% 18% 6% 1	567
	21st to end	Day	24% 19% 30% 15% 10% 1	617
June	1st to 10th	Day	24% 19% 33% 18% 5% 2	570
	11th to 20th	Day	23% 19% 30% 19% 8% 2	550
	21st to end	Day	24% 19% 33% 16% 6% 2	530
July	1st to 10th	Day	17% 12% 34% 22% 12% 3	525
	11th to 20th	Day	13% 12% 38% 26% 9% 2	524
	21st to end	Day	16% 14% 38% 23% 7% 2	576
August	1st to 10th	Day	13% 14% 30% 26% 12% 5%	526
	11th to 20th	Day	16% 12% 33% 21% 12% 6%	519
	21st to end	Day	14% 19% 31% 21% 10% 5%	583
September	1st to 10th	Day	19% 12% 29% 21% 12% 8%	530
	11th to 20th	Day	14% 15% 25% 20% 14% 12%	530
	21st to end	Day	18% 17% 31% 18% 11% 5%	530
October	1st to 10th	Day	28% 15% 25% 16% 12% 4	530
	11th to 20th	Day	25% 24% 28% 15% 6% 1	530
	21st to end	Day	33% 21% 26% 16% 4	476
November	1st to 10th	Day	32% 22% 24% 16% 6%	425
	11th to 20th	Day	30% 25% 27% 12% 5% 1	377
	21st to end	Day	40% 25% 26% 9%	220
December	1st to 10th	Day	39% 23% 28% 8% 2	220
	11th to 20th	Day	39% 27% 27% 5% 1	220
	21st to end	Day	34% 28% 30% 7% 2	242
January	1st to 10th	Night	26% 29% 32% 12% 1	840
	11th to 20th	Night	29% 27% 29% 12% 2	840
	21st to end	Night	21% 28% 32% 15% 4	924
February	1st to 10th	Night	23% 29% 33% 13% 1	840
	11th to 20th	Night	26% 30% 32% 12% 1	823
	21st to end	Night	26% 26% 35% 11% 2	692
March	1st to 10th	Night	29% 24% 30% 15% 2	840
	11th to 20th	Night	29% 25% 27% 15% 3	840
	21st to end	Night	26% 25% 28% 15% 6%	924
April	1st to 10th	Night	27% 23% 30% 17% 3	840
	11th to 20th	Night	28% 24% 26% 15% 6%	831
	21st to end	Night	28% 20% 25% 20% 5% 1	757
May	1st to 10th	Night	28% 18% 25% 21% 8%	499
	11th to 20th	Night	18% 17% 32% 26% 6%	414
	21st to end	Night	17% 12% 32% 28% 11% 1	455
June	1st to 10th	Night	22% 11% 29% 28% 10%	420
	11th to 20th	Night	21% 12% 24% 29% 13%	410
	21st to end	Night	20% 12% 32% 27% 9% 1	400
July	1st to 10th	Night	13% 8% 28% 37% 14% 1	390
	11th to 20th	Night	13% 6% 29% 34% 17% 2	388
	21st to end	Night	13% 9% 26% 41% 10% 1	438
August	1st to 10th	Night	15% 7% 23% 38% 15% 1	411
	11th to 20th	Night	16% 7% 24% 29% 22% 2	706
	21st to end	Night	17% 10% 25% 31% 17% 1	880
September	1st to 10th	Night	16% 12% 25% 30% 16% 2	800
	11th to 20th	Night	16% 9% 23% 27% 20% 4	800
	21st to end	Night	22% 13% 24% 22% 17% 2	800
October	1st to 10th	Night	25% 16% 23% 19% 15% 2	800
	11th to 20th	Night	26% 17% 27% 23% 7% 1	800
	21st to end	Night	32% 22% 25% 19% 3	880
November	1st to 10th	Night	26% 22% 29% 17% 5%	820
	11th to 20th	Night	28% 25% 26% 13% 7% 1	840
	21st to end	Night	29% 26% 26% 14% 4 1	840
December	1st to 10th	Night	29% 29% 27% 12% 3	840
	11th to 20th	Night	29% 28% 25% 13% 3 1	840
	21st to end	Night	30% 30% 25% 12% 4	924

Page generated at 2026-06-13 02:31:45. Version ac07

Copyright © 2026 Attilla Danko.