Baddeck
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Baddeck clear sky chart from 2005-11-06 to 2026-04-02.

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	20% 11% 4 10% 6% 5% 5% 4 5% 6% 24%	131688
	Night	21% 12% 4 11% 6% 5% 5% 4 5% 6% 22%	130404
Transparency	Day	60% 7% 11% 15% 6%	135161
	Night	62% 7% 11% 14% 6%	135028
Seeing	Day	30% 23% 28% 14% 4 1	19534
	Night	30% 20% 26% 19% 5%	27063

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	12% 17% 6% 21% 10% 7% 6% 4 4 4 9%	4690
	11th to 20th	Day	19% 14% 8% 18% 8% 6% 5% 3 4 5% 9%	4681
	21st to end	Day	12% 11% 6% 16% 10% 11% 6% 4 4 5% 16%	5288
February	1st to 10th	Day	18% 14% 5% 15% 9% 6% 6% 4 5% 4 13%	1890
	11th to 20th	Day	15% 15% 5% 12% 9% 7% 5% 5% 6% 7% 15%	1843
	21st to end	Day	13% 15% 6% 10% 9% 5% 4 3 4 6% 25%	1723
March	1st to 10th	Day	22% 12% 4 10% 9% 6% 5% 3 3 4 23%	4574
	11th to 20th	Day	16% 18% 5% 11% 6% 5% 5% 4 5% 6% 21%	5078
	21st to end	Day	28% 12% 5% 14% 6% 5% 4 4 4 4 15%	5908
April	1st to 10th	Day	22% 16% 4 9% 6% 4 4 4 5% 6% 20%	2412
	11th to 20th	Day	20% 14% 3 7% 4 4 4 3 4 6% 31%	2374
	21st to end	Day	23% 14% 3 8% 4 4 4 3 5% 6% 27%	2581
May	1st to 10th	Day	25% 16% 4 8% 4 4 4 3 4 5% 23%	6345
	11th to 20th	Day	20% 9% 3 7% 5% 5% 4 3 5% 6% 31%	6318
	21st to end	Day	22% 11% 3 7% 4 4 4 3 5% 7% 31%	6948
June	1st to 10th	Day	29% 9% 3 8% 5% 4 4 3 5% 6% 23%	2800
	11th to 20th	Day	20% 9% 3 6% 4 4 5% 4 5% 7% 33%	2800
	21st to end	Day	30% 11% 3 8% 5% 4 4 3 5% 5% 23%	2800
July	1st to 10th	Day	21% 10% 4 8% 6% 5% 4 4 5% 7% 24%	6360
	11th to 20th	Day	18% 7% 3 7% 5% 5% 5% 3 6% 8% 34%	6360
	21st to end	Day	16% 6% 2 6% 4 4 5% 5% 8% 9% 36%	6927
August	1st to 10th	Day	20% 9% 3 8% 5% 6% 5% 4 6% 7% 26%	4544
	11th to 20th	Day	20% 7% 3 7% 5% 5% 5% 4 7% 8% 30%	4147
	21st to end	Day	13% 8% 3 7% 5% 5% 5% 4 6% 7% 38%	4312
September	1st to 10th	Day	19% 6% 3 6% 5% 4 4 4 6% 9% 35%	2400
	11th to 20th	Day	21% 7% 3 7% 5% 5% 5% 4 5% 8% 31%	2400
	21st to end	Day	20% 6% 3 6% 4 4 5% 3 6% 7% 35%	2135
October	1st to 10th	Day	18% 8% 3 8% 6% 5% 5% 3 6% 8% 31%	2000
	11th to 20th	Day	22% 8% 4 9% 5% 6% 5% 4 6% 7% 24%	2000
	21st to end	Day	23% 12% 4 10% 6% 5% 6% 5% 5% 6% 19%	2021
November	1st to 10th	Day	24% 14% 5% 10% 6% 5% 5% 3 4 6% 18%	1833
	11th to 20th	Day	25% 19% 5% 11% 6% 5% 5% 3 4 5% 12%	1680
	21st to end	Day	19% 18% 6% 12% 7% 7% 5% 4 7% 4 12%	1680
December	1st to 10th	Day	17% 16% 7% 15% 8% 5% 5% 4 5% 6% 12%	2690
	11th to 20th	Day	31% 12% 5% 15% 7% 5% 5% 3 3 3 10%	3076
	21st to end	Day	20% 14% 7% 16% 8% 6% 5% 4 4 4 13%	4070
January	1st to 10th	Night	15% 16% 7% 17% 9% 7% 6% 3 5% 5% 10%	8234
	11th to 20th	Night	22% 14% 7% 22% 7% 5% 5% 3 4 3 9%	8234
	21st to end	Night	10% 12% 5% 18% 13% 11% 6% 4 5% 4 13%	8902
February	1st to 10th	Night	18% 12% 5% 14% 7% 7% 7% 5% 5% 4 15%	2730
	11th to 20th	Night	17% 13% 5% 11% 7% 7% 6% 4 6% 6% 19%	2663
	21st to end	Night	12% 13% 6% 12% 7% 6% 5% 5% 6% 5% 23%	2081
March	1st to 10th	Night	22% 11% 4 9% 9% 6% 4 3 5% 5% 22%	5486
	11th to 20th	Night	20% 12% 4 10% 5% 5% 4 4 5% 6% 24%	5099
	21st to end	Night	28% 13% 5% 12% 6% 5% 4 2 2 3 18%	5265
April	1st to 10th	Night	24% 12% 4 7% 5% 5% 4 4 5% 6% 25%	2011
	11th to 20th	Night	19% 12% 5% 8% 5% 4 4 3 5% 6% 31%	1976
	21st to end	Night	25% 11% 3 6% 5% 4 3 3 4 4 32%	1815
May	1st to 10th	Night	24% 16% 3 6% 4 4 4 3 5% 6% 24%	3615
	11th to 20th	Night	19% 12% 3 7% 3 3 4 4 6% 7% 32%	3596
	21st to end	Night	17% 12% 4 8% 5% 4 4 3 5% 7% 29%	3948
June	1st to 10th	Night	31% 11% 3 6% 4 4 4 3 4 5% 25%	1600
	11th to 20th	Night	25% 8% 2 5% 5% 2 4 3 4 6% 37%	1600
	21st to end	Night	29% 11% 4 7% 5% 4 4 4 5% 6% 22%	1600
July	1st to 10th	Night	23% 10% 4 9% 5% 5% 4 4 6% 7% 22%	3619
	11th to 20th	Night	23% 10% 3 6% 3 4 4 3 5% 6% 33%	3620
	21st to end	Night	21% 8% 2 6% 4 4 5% 5% 6% 7% 32%	3948
August	1st to 10th	Night	21% 8% 3 8% 5% 4 4 5% 6% 5% 30%	2612
	11th to 20th	Night	23% 8% 3 6% 4 4 5% 3 7% 8% 30%	2899
	21st to end	Night	16% 6% 2 5% 3 3 3 4 6% 9% 43%	3586
September	1st to 10th	Night	20% 5% 2 5% 4 4 4 4 7% 7% 37%	2000
	11th to 20th	Night	23% 6% 2 5% 4 3 4 4 5% 7% 38%	2000
	21st to end	Night	20% 7% 3 5% 4 4 5% 4 5% 6% 37%	2261
October	1st to 10th	Night	18% 7% 2 7% 4 5% 5% 3 6% 7% 36%	2400
	11th to 20th	Night	24% 8% 2 5% 5% 4 5% 4 6% 7% 30%	2400
	21st to end	Night	25% 12% 3 8% 5% 5% 5% 4 6% 7% 22%	2817
November	1st to 10th	Night	22% 11% 4 9% 6% 5% 5% 4 6% 6% 21%	2684
	11th to 20th	Night	26% 14% 3 10% 6% 6% 5% 4 6% 5% 15%	2940
	21st to end	Night	24% 14% 5% 10% 6% 6% 5% 4 6% 7% 14%	2940
December	1st to 10th	Night	19% 12% 6% 11% 6% 5% 5% 4 6% 6% 19%	4720
	11th to 20th	Night	29% 11% 4 13% 6% 5% 5% 4 4 5% 14%	5353
	21st to end	Night	24% 12% 7% 14% 6% 5% 4 3 4 5% 18%	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	78% 7% 6% 7% 2	4691
	11th to 20th	Day	77% 5% 10% 6% 2	4710
	21st to end	Day	68% 5% 8% 11% 7% 1	5288
February	1st to 10th	Day	72% 7% 7% 9% 5%	1890
	11th to 20th	Day	68% 8% 11% 9% 3 1	1851
	21st to end	Day	61% 5% 9% 13% 9% 2	1723
March	1st to 10th	Day	66% 4 8% 13% 8%	4578
	11th to 20th	Day	65% 7% 14% 9% 5%	5078
	21st to end	Day	72% 5% 8% 10% 5% 1	5908
April	1st to 10th	Day	64% 6% 9% 11% 7% 2	2412
	11th to 20th	Day	55% 6% 10% 16% 11% 1	2374
	21st to end	Day	60% 7% 10% 13% 10% 1	2581
May	1st to 10th	Day	65% 7% 8% 13% 6% 1	6357
	11th to 20th	Day	53% 8% 15% 17% 8%	6322
	21st to end	Day	52% 7% 13% 21% 7%	6948
June	1st to 10th	Day	61% 8% 9% 16% 6%	2800
	11th to 20th	Day	49% 8% 13% 20% 9% 1	2800
	21st to end	Day	63% 7% 9% 14% 8%	2800
July	1st to 10th	Day	58% 7% 14% 13% 8%	6290
	11th to 20th	Day	47% 8% 14% 25% 5%	6284
	21st to end	Day	42% 9% 19% 23% 6%	6730
August	1st to 10th	Day	56% 8% 13% 17% 6%	4530
	11th to 20th	Day	50% 10% 14% 22% 4	4186
	21st to end	Day	43% 7% 12% 27% 10%	4312
September	1st to 10th	Day	46% 7% 13% 23% 10% 1	2400
	11th to 20th	Day	52% 6% 12% 20% 9% 1	2400
	21st to end	Day	47% 6% 12% 24% 11% 1	2135
October	1st to 10th	Day	54% 6% 12% 18% 9%	3260
	11th to 20th	Day	53% 7% 10% 21% 8%	3240
	21st to end	Day	59% 7% 13% 17% 3	3255
November	1st to 10th	Day	67% 6% 12% 12% 3	1833
	11th to 20th	Day	75% 6% 10% 7% 3	1680
	21st to end	Day	73% 6% 12% 6% 3	1680
December	1st to 10th	Day	71% 7% 7% 12% 2	2690
	11th to 20th	Day	79% 5% 6% 7% 3	3075
	21st to end	Day	74% 8% 10% 7% 2	4070
January	1st to 10th	Night	75% 9% 9% 5% 2	8234
	11th to 20th	Night	80% 6% 7% 6% 2	8280
	21st to end	Night	72% 7% 8% 8% 6%	8902
February	1st to 10th	Night	70% 7% 9% 8% 5% 1	2730
	11th to 20th	Night	67% 7% 9% 13% 4 1	2666
	21st to end	Night	63% 6% 9% 12% 9% 1	2081
March	1st to 10th	Night	64% 5% 8% 13% 10% 1	5495
	11th to 20th	Night	59% 8% 14% 12% 8%	5100
	21st to end	Night	73% 4 5% 12% 5% 1	5265
April	1st to 10th	Night	61% 6% 9% 12% 10% 1	2011
	11th to 20th	Night	54% 6% 9% 18% 11% 1	1976
	21st to end	Night	57% 5% 9% 18% 10% 2	1815
May	1st to 10th	Night	59% 8% 12% 14% 7%	3620
	11th to 20th	Night	52% 7% 13% 21% 7% 1	3597
	21st to end	Night	52% 8% 11% 23% 6%	3949
June	1st to 10th	Night	63% 5% 9% 16% 6% 1	1600
	11th to 20th	Night	50% 5% 11% 21% 12% 1	1600
	21st to end	Night	62% 6% 10% 14% 8% 1	1600
July	1st to 10th	Night	60% 7% 13% 14% 6%	3581
	11th to 20th	Night	51% 7% 11% 21% 9% 1	3572
	21st to end	Night	50% 7% 15% 22% 5%	3831
August	1st to 10th	Night	54% 7% 15% 19% 5%	2601
	11th to 20th	Night	51% 8% 19% 18% 4	2926
	21st to end	Night	37% 9% 16% 30% 9%	3585
September	1st to 10th	Night	44% 8% 13% 23% 11%	2000
	11th to 20th	Night	47% 7% 12% 24% 10% 1	2000
	21st to end	Night	48% 7% 10% 26% 9% 1	2261
October	1st to 10th	Night	51% 7% 14% 18% 9%	3920
	11th to 20th	Night	49% 6% 12% 25% 7%	3899
	21st to end	Night	57% 7% 13% 18% 6%	4542
November	1st to 10th	Night	61% 9% 13% 12% 4	2684
	11th to 20th	Night	69% 8% 10% 9% 3	2940
	21st to end	Night	68% 9% 11% 8% 3	2940
December	1st to 10th	Night	63% 8% 9% 16% 4	4720
	11th to 20th	Night	73% 6% 9% 10% 3	5355
	21st to end	Night	70% 6% 10% 12% 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% 28% 26% 9% 1	430
	11th to 20th	Day	33% 27% 25% 10% 4	430
	21st to end	Day	27% 31% 30% 9% 3	473
February	1st to 10th	Day	32% 29% 25% 12% 2	430
	11th to 20th	Day	35% 33% 21% 9% 2	426
	21st to end	Day	26% 33% 24% 13% 3 1	355
March	1st to 10th	Day	27% 35% 24% 10% 4	430
	11th to 20th	Day	27% 31% 28% 10% 3 1	535
	21st to end	Day	35% 32% 21% 9% 2 1	594
April	1st to 10th	Day	38% 32% 22% 7% 1	504
	11th to 20th	Day	33% 30% 24% 11% 2	492
	21st to end	Day	34% 26% 25% 12% 2 1	575
May	1st to 10th	Day	37% 25% 22% 10% 4 2	703
	11th to 20th	Day	30% 19% 27% 15% 8% 1	724
	21st to end	Day	27% 23% 31% 15% 4 1	790
June	1st to 10th	Day	39% 15% 26% 16% 4	730
	11th to 20th	Day	24% 22% 34% 14% 5% 1	730
	21st to end	Day	36% 18% 27% 13% 5% 1	730
July	1st to 10th	Day	27% 16% 33% 19% 5% 1	720
	11th to 20th	Day	24% 13% 33% 22% 7%	718
	21st to end	Day	28% 14% 31% 20% 6% 1	795
August	1st to 10th	Day	20% 13% 36% 21% 9% 1	718
	11th to 20th	Day	25% 12% 34% 21% 6% 1	519
	21st to end	Day	22% 17% 36% 17% 7% 1	583
September	1st to 10th	Day	23% 19% 37% 15% 5% 2	530
	11th to 20th	Day	29% 18% 32% 14% 6% 1	530
	21st to end	Day	25% 20% 29% 18% 7% 1	420
October	1st to 10th	Day	23% 19% 34% 15% 8% 1	420
	11th to 20th	Day	28% 23% 26% 16% 4 3	420
	21st to end	Day	34% 23% 26% 11% 6%	462
November	1st to 10th	Day	36% 26% 21% 11% 4 1	425
	11th to 20th	Day	40% 25% 21% 10% 2 1	430
	21st to end	Day	37% 30% 21% 11% 2	430
December	1st to 10th	Day	36% 29% 22% 10% 3	430
	11th to 20th	Day	40% 29% 21% 9% 1	430
	21st to end	Day	30% 34% 21% 12% 2 1	473
January	1st to 10th	Night	31% 29% 25% 12% 3	950
	11th to 20th	Night	31% 29% 23% 13% 4	950
	21st to end	Night	26% 30% 26% 14% 4	1017
February	1st to 10th	Night	30% 24% 26% 17% 3	840
	11th to 20th	Night	29% 32% 22% 13% 3	823
	21st to end	Night	23% 26% 29% 17% 5%	692
March	1st to 10th	Night	25% 27% 29% 16% 3	840
	11th to 20th	Night	24% 25% 25% 19% 7%	840
	21st to end	Night	30% 24% 27% 15% 4 1	783
April	1st to 10th	Night	32% 22% 24% 19% 2	604
	11th to 20th	Night	28% 16% 31% 21% 4	594
	21st to end	Night	32% 17% 28% 17% 6%	600
May	1st to 10th	Night	34% 16% 26% 17% 7% 2	600
	11th to 20th	Night	26% 12% 30% 23% 8%	592
	21st to end	Night	24% 16% 31% 23% 5%	649
June	1st to 10th	Night	36% 11% 29% 21% 3	600
	11th to 20th	Night	28% 11% 31% 25% 6%	600
	21st to end	Night	35% 8% 31% 22% 4	600
July	1st to 10th	Night	27% 8% 28% 29% 7% 1	586
	11th to 20th	Night	26% 9% 27% 32% 5%	582
	21st to end	Night	29% 7% 29% 28% 7%	656
August	1st to 10th	Night	22% 7% 25% 35% 10% 1	598
	11th to 20th	Night	27% 7% 24% 31% 11% 1	592
	21st to end	Night	21% 9% 25% 33% 11%	660
September	1st to 10th	Night	22% 10% 28% 30% 10% 1	600
	11th to 20th	Night	27% 12% 27% 23% 11% 1	600
	21st to end	Night	25% 14% 31% 23% 6% 1	662
October	1st to 10th	Night	25% 14% 26% 26% 9%	800
	11th to 20th	Night	30% 15% 24% 22% 8% 2	800
	21st to end	Night	34% 21% 25% 16% 4	978
November	1st to 10th	Night	34% 19% 28% 15% 3 1	930
	11th to 20th	Night	39% 22% 20% 14% 5% 1	950
	21st to end	Night	34% 27% 23% 13% 3	950
December	1st to 10th	Night	35% 27% 24% 11% 4	950
	11th to 20th	Night	37% 29% 22% 9% 3	950
	21st to end	Night	33% 28% 24% 12% 2 1	1045

Page generated at 2026-03-30 03:18:41. Version ac07

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