Blomidon Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Blomidon Provincial Park 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	19% 11% 4 9% 5% 5% 4 3 5% 6% 29%	120867
	Night	20% 13% 4 10% 6% 5% 4 3 4 5% 26%	118318
Transparency	Day	54% 8% 12% 18% 9% 1	124486
	Night	57% 7% 11% 16% 8% 1	122860
Seeing	Day	24% 10% 27% 27% 11% 1	18150
	Night	25% 13% 30% 25% 8% 1	25518

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	16% 22% 8% 14% 7% 5% 4 3 3 3 16%	3318
	11th to 20th	Day	14% 17% 9% 19% 7% 7% 5% 3 4 4 12%	3738
	21st to end	Day	12% 12% 5% 13% 9% 9% 6% 4 4 5% 21%	4466
February	1st to 10th	Day	18% 14% 4 11% 10% 6% 6% 4 5% 4 16%	1800
	11th to 20th	Day	16% 13% 5% 13% 9% 6% 5% 4 5% 4 20%	1753
	21st to end	Day	11% 12% 5% 10% 7% 6% 5% 4 5% 7% 29%	1495
March	1st to 10th	Day	22% 12% 4 12% 7% 6% 4 3 4 5% 22%	4930
	11th to 20th	Day	14% 12% 5% 9% 5% 5% 5% 4 5% 7% 29%	4980
	21st to end	Day	25% 15% 4 9% 5% 5% 5% 3 4 5% 21%	5466
April	1st to 10th	Day	22% 12% 4 8% 5% 4 4 3 5% 7% 27%	2379
	11th to 20th	Day	18% 10% 3 8% 4 4 4 4 6% 7% 33%	2477
	21st to end	Day	20% 10% 2 7% 5% 4 5% 4 5% 6% 31%	2600
May	1st to 10th	Day	27% 11% 4 8% 5% 5% 5% 4 5% 5% 21%	6018
	11th to 20th	Day	19% 10% 3 9% 5% 4 4 3 5% 6% 32%	6318
	21st to end	Day	19% 9% 2 7% 5% 4 4 3 6% 8% 31%	6948
June	1st to 10th	Day	21% 10% 3 8% 5% 5% 5% 4 6% 6% 27%	2820
	11th to 20th	Day	20% 7% 3 7% 4 4 4 3 6% 7% 34%	3000
	21st to end	Day	24% 9% 3 7% 5% 5% 4 4 5% 6% 28%	3000
July	1st to 10th	Day	22% 9% 2 7% 4 4 5% 4 5% 7% 32%	4910
	11th to 20th	Day	20% 9% 3 7% 3 3 4 4 6% 7% 34%	4628
	21st to end	Day	14% 8% 3 7% 5% 4 5% 4 6% 9% 35%	4666
August	1st to 10th	Day	19% 11% 4 8% 5% 4 5% 4 5% 6% 30%	4105
	11th to 20th	Day	14% 7% 3 7% 5% 4 5% 4 6% 8% 38%	4045
	21st to end	Day	10% 5% 2 6% 4 4 5% 3 5% 7% 50%	4385
September	1st to 10th	Day	15% 6% 3 6% 5% 4 4 3 5% 7% 43%	2280
	11th to 20th	Day	16% 7% 2 7% 4 3 3 3 4 5% 45%	2188
	21st to end	Day	15% 7% 2 6% 4 4 3 3 5% 7% 43%	2043
October	1st to 10th	Day	16% 8% 4 6% 5% 4 4 3 5% 7% 39%	1900
	11th to 20th	Day	19% 9% 3 6% 4 4 5% 5% 5% 7% 34%	1900
	21st to end	Day	19% 12% 3 7% 6% 4 4 3 4 6% 31%	2090
November	1st to 10th	Day	21% 12% 4 8% 5% 5% 4 4 3 5% 29%	1601
	11th to 20th	Day	19% 17% 5% 7% 6% 5% 4 3 4 5% 25%	1600
	21st to end	Day	19% 17% 5% 12% 7% 4 4 4 3 4 21%	1600
December	1st to 10th	Day	21% 13% 7% 15% 6% 4 4 3 3 4 19%	2610
	11th to 20th	Day	26% 16% 5% 11% 6% 5% 3 3 3 3 19%	2996
	21st to end	Day	19% 16% 7% 15% 5% 3 3 3 4 4 20%	3814
January	1st to 10th	Night	15% 20% 7% 13% 8% 6% 4 3 3 4 18%	6608
	11th to 20th	Night	17% 16% 7% 18% 6% 5% 5% 3 3 4 14%	6159
	21st to end	Night	12% 13% 5% 13% 9% 9% 7% 3 4 5% 20%	6490
February	1st to 10th	Night	19% 16% 5% 11% 9% 7% 5% 4 4 4 16%	2600
	11th to 20th	Night	18% 13% 5% 11% 8% 5% 5% 4 6% 5% 21%	2533
	21st to end	Night	13% 14% 5% 11% 7% 5% 5% 4 4 5% 28%	2129
March	1st to 10th	Night	25% 14% 5% 12% 8% 5% 3 2 2 3 22%	4910
	11th to 20th	Night	18% 13% 5% 10% 5% 4 4 4 5% 5% 26%	4979
	21st to end	Night	30% 12% 5% 8% 5% 4 3 2 3 4 24%	5466
April	1st to 10th	Night	23% 14% 3 8% 5% 5% 4 3 4 5% 27%	2020
	11th to 20th	Night	21% 10% 4 7% 5% 4 4 3 4 6% 31%	1869
	21st to end	Night	23% 10% 4 8% 5% 4 4 3 5% 6% 30%	1800
May	1st to 10th	Night	30% 13% 3 8% 4 4 4 3 4 5% 22%	3927
	11th to 20th	Night	24% 10% 3 6% 4 4 4 4 5% 7% 29%	3596
	21st to end	Night	18% 12% 4 10% 5% 5% 5% 3 4 6% 29%	3948
June	1st to 10th	Night	23% 10% 3 8% 5% 5% 5% 4 6% 6% 25%	1594
	11th to 20th	Night	20% 8% 3 7% 4 4 5% 3 5% 6% 35%	1400
	21st to end	Night	22% 10% 3 9% 5% 5% 5% 4 5% 6% 25%	1400
July	1st to 10th	Night	20% 14% 4 8% 5% 5% 4 4 5% 7% 23%	2280
	11th to 20th	Night	21% 10% 3 8% 4 4 5% 4 6% 8% 27%	2525
	21st to end	Night	14% 8% 3 7% 5% 5% 4 4 6% 8% 35%	2892
August	1st to 10th	Night	22% 10% 3 7% 5% 5% 4 4 6% 6% 28%	2825
	11th to 20th	Night	15% 10% 3 8% 5% 4 6% 3 6% 7% 33%	2782
	21st to end	Night	13% 6% 2 6% 4 4 4 4 5% 7% 45%	3270
September	1st to 10th	Night	13% 7% 3 6% 4 4 5% 4 5% 7% 42%	1900
	11th to 20th	Night	17% 7% 2 6% 4 3 4 2 5% 6% 44%	1990
	21st to end	Night	17% 8% 2 7% 5% 4 4 3 5% 7% 38%	2137
October	1st to 10th	Night	17% 6% 3 6% 4 4 5% 4 5% 6% 39%	2280
	11th to 20th	Night	18% 8% 3 7% 5% 4 4 3 5% 7% 35%	2280
	21st to end	Night	25% 11% 3 8% 5% 4 3 3 3 5% 30%	2508
November	1st to 10th	Night	21% 10% 3 8% 5% 5% 4 3 5% 6% 31%	2691
	11th to 20th	Night	20% 15% 5% 9% 5% 5% 5% 4 4 5% 22%	2800
	21st to end	Night	23% 15% 5% 10% 6% 5% 4 3 3 5% 20%	2800
December	1st to 10th	Night	17% 15% 5% 15% 9% 6% 4 4 5% 5% 16%	4580
	11th to 20th	Night	23% 16% 4 9% 7% 4 4 3 4 4 23%	5213
	21st to end	Night	25% 15% 4 12% 5% 4 3 3 4 4 22%	7137

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	73% 7% 8% 8% 3	3319
	11th to 20th	Day	70% 9% 10% 9% 2	3768
	21st to end	Day	59% 10% 11% 9% 10% 2	4466
February	1st to 10th	Day	69% 4 10% 10% 6% 1	1800
	11th to 20th	Day	66% 7% 11% 11% 5% 1	1761
	21st to end	Day	53% 7% 13% 16% 10% 1	1495
March	1st to 10th	Day	63% 6% 8% 12% 9% 1	4934
	11th to 20th	Day	54% 8% 13% 18% 7% 1	4980
	21st to end	Day	66% 4 6% 15% 8% 1	5466
April	1st to 10th	Day	57% 7% 9% 13% 11% 3	2379
	11th to 20th	Day	51% 5% 10% 22% 12% 1	2477
	21st to end	Day	53% 5% 10% 19% 11% 2	2600
May	1st to 10th	Day	61% 8% 10% 14% 7%	6029
	11th to 20th	Day	50% 10% 12% 22% 5%	6322
	21st to end	Day	47% 9% 15% 18% 10%	6948
June	1st to 10th	Day	56% 7% 11% 19% 6% 1	2820
	11th to 20th	Day	48% 7% 14% 20% 10% 1	3000
	21st to end	Day	56% 8% 10% 17% 9% 1	3000
July	1st to 10th	Day	50% 6% 13% 18% 11% 1	4835
	11th to 20th	Day	46% 9% 14% 22% 8%	4550
	21st to end	Day	43% 11% 16% 21% 9%	4517
August	1st to 10th	Day	53% 8% 11% 19% 9%	4092
	11th to 20th	Day	43% 9% 13% 23% 11% 1	4084
	21st to end	Day	32% 8% 14% 29% 16% 1	4385
September	1st to 10th	Day	39% 8% 12% 25% 14% 1	2280
	11th to 20th	Day	41% 6% 12% 25% 15% 1	2188
	21st to end	Day	41% 6% 11% 28% 14% 1	2043
October	1st to 10th	Day	42% 8% 13% 25% 11%	3160
	11th to 20th	Day	43% 7% 11% 28% 11%	3140
	21st to end	Day	46% 5% 15% 21% 13%	3428
November	1st to 10th	Day	58% 5% 10% 18% 8%	1601
	11th to 20th	Day	62% 6% 11% 13% 6% 1	1600
	21st to end	Day	66% 7% 12% 11% 4	1600
December	1st to 10th	Day	66% 9% 11% 11% 2	2610
	11th to 20th	Day	69% 7% 7% 12% 4 1	2995
	21st to end	Day	65% 9% 11% 10% 5%	3814
January	1st to 10th	Night	65% 11% 9% 11% 2	6608
	11th to 20th	Night	71% 9% 8% 9% 3	6204
	21st to end	Night	62% 9% 11% 12% 5% 1	6490
February	1st to 10th	Night	70% 6% 8% 9% 6% 1	2600
	11th to 20th	Night	63% 7% 12% 12% 6% 1	2536
	21st to end	Night	56% 6% 11% 17% 9% 1	2129
March	1st to 10th	Night	68% 4 5% 11% 10% 2	4919
	11th to 20th	Night	56% 7% 14% 15% 7% 1	4980
	21st to end	Night	65% 4 7% 16% 8% 1	5466
April	1st to 10th	Night	59% 5% 9% 12% 12% 3	2020
	11th to 20th	Night	55% 5% 8% 19% 13% 1	1869
	21st to end	Night	56% 5% 10% 15% 12% 2	1800
May	1st to 10th	Night	64% 6% 10% 12% 7% 1	3933
	11th to 20th	Night	52% 9% 11% 21% 6% 2	3597
	21st to end	Night	52% 8% 15% 18% 7%	3949
June	1st to 10th	Night	56% 7% 11% 19% 6% 1	1594
	11th to 20th	Night	48% 7% 11% 24% 9% 1	1400
	21st to end	Night	57% 7% 12% 15% 7% 2	1400
July	1st to 10th	Night	54% 11% 12% 13% 8% 1	2245
	11th to 20th	Night	48% 10% 16% 16% 9%	2480
	21st to end	Night	43% 8% 14% 23% 11%	2801
August	1st to 10th	Night	52% 8% 13% 21% 5%	2813
	11th to 20th	Night	45% 11% 15% 21% 9%	2809
	21st to end	Night	35% 9% 16% 26% 15%	3269
September	1st to 10th	Night	39% 8% 11% 29% 13% 1	1900
	11th to 20th	Night	40% 6% 12% 28% 14% 1	1990
	21st to end	Night	45% 6% 10% 26% 13% 1	2137
October	1st to 10th	Night	46% 6% 12% 25% 10%	3800
	11th to 20th	Night	39% 6% 14% 28% 12%	3779
	21st to end	Night	46% 4 14% 22% 14%	4120
November	1st to 10th	Night	54% 6% 13% 18% 8% 1	2691
	11th to 20th	Night	63% 7% 10% 13% 6%	2800
	21st to end	Night	65% 7% 13% 11% 3	2800
December	1st to 10th	Night	62% 13% 12% 11% 2	4580
	11th to 20th	Night	63% 7% 10% 15% 5% 1	5215
	21st to end	Night	64% 7% 10% 14% 5%	7137

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	26% 20% 31% 19% 4	270
	11th to 20th	Day	30% 17% 31% 15% 7% 1	400
	21st to end	Day	19% 13% 39% 25% 3	440
February	1st to 10th	Day	26% 16% 30% 23% 4 1	400
	11th to 20th	Day	23% 20% 36% 18% 3	396
	21st to end	Day	19% 13% 34% 28% 5%	334
March	1st to 10th	Day	22% 19% 33% 21% 5%	500
	11th to 20th	Day	17% 16% 34% 26% 7%	500
	21st to end	Day	26% 13% 31% 23% 6% 1	550
April	1st to 10th	Day	31% 13% 35% 18% 3 1	500
	11th to 20th	Day	22% 10% 36% 23% 8% 1	492
	21st to end	Day	24% 10% 25% 29% 10% 1	500
May	1st to 10th	Day	28% 9% 29% 25% 8% 1	557
	11th to 20th	Day	23% 5% 27% 29% 13% 2	724
	21st to end	Day	26% 7% 25% 32% 10% 1	790
June	1st to 10th	Day	27% 6% 25% 28% 12% 1	730
	11th to 20th	Day	23% 5% 21% 35% 15% 1	730
	21st to end	Day	29% 5% 18% 32% 12% 3	730
July	1st to 10th	Day	22% 4 18% 37% 19% 1	720
	11th to 20th	Day	21% 4 17% 34% 21% 3	718
	21st to end	Day	21% 3 17% 37% 20% 2	653
August	1st to 10th	Day	16% 5% 13% 39% 25% 2	486
	11th to 20th	Day	20% 4 20% 33% 19% 4	479
	21st to end	Day	14% 5% 22% 33% 21% 4	539
September	1st to 10th	Day	16% 5% 24% 36% 17% 3	490
	11th to 20th	Day	18% 6% 24% 30% 17% 4	490
	21st to end	Day	19% 7% 24% 26% 20% 3	465
October	1st to 10th	Day	21% 8% 23% 30% 15% 3	390
	11th to 20th	Day	21% 12% 28% 25% 13% 1	390
	21st to end	Day	24% 12% 32% 22% 8% 1	429
November	1st to 10th	Day	24% 13% 31% 24% 7% 1	395
	11th to 20th	Day	29% 21% 27% 17% 6%	400
	21st to end	Day	30% 18% 35% 15% 2 1	400
December	1st to 10th	Day	34% 14% 31% 18% 3 1	400
	11th to 20th	Day	36% 21% 27% 14% 3	400
	21st to end	Day	27% 16% 33% 18% 5% 1	363
January	1st to 10th	Night	27% 19% 34% 17% 3	900
	11th to 20th	Night	29% 17% 30% 19% 5%	867
	21st to end	Night	20% 21% 38% 16% 5%	880
February	1st to 10th	Night	26% 19% 35% 17% 3	800
	11th to 20th	Night	26% 20% 35% 16% 2 1	783
	21st to end	Night	19% 15% 38% 23% 5%	660
March	1st to 10th	Night	23% 16% 36% 21% 3	800
	11th to 20th	Night	21% 15% 30% 26% 7%	800
	21st to end	Night	25% 13% 33% 23% 6%	880
April	1st to 10th	Night	29% 14% 33% 20% 5%	620
	11th to 20th	Night	25% 11% 34% 24% 6%	594
	21st to end	Night	29% 9% 33% 22% 7% 1	600
May	1st to 10th	Night	30% 7% 29% 26% 7% 1	600
	11th to 20th	Night	28% 6% 25% 30% 11% 1	592
	21st to end	Night	21% 6% 33% 32% 8%	649
June	1st to 10th	Night	26% 8% 25% 30% 10% 1	594
	11th to 20th	Night	23% 5% 21% 40% 10% 1	400
	21st to end	Night	25% 5% 19% 39% 12% 1	400
July	1st to 10th	Night	23% 4 18% 39% 15% 1	390
	11th to 20th	Night	18% 5% 20% 40% 16% 1	526
	21st to end	Night	19% 5% 18% 42% 16%	624
August	1st to 10th	Night	17% 3 21% 41% 16% 1	568
	11th to 20th	Night	20% 4 24% 33% 17% 2	562
	21st to end	Night	16% 5% 21% 34% 22% 2	627
September	1st to 10th	Night	16% 5% 28% 34% 16% 1	570
	11th to 20th	Night	18% 6% 24% 34% 16% 1	660
	21st to end	Night	21% 9% 27% 28% 12% 2	760
October	1st to 10th	Night	21% 7% 30% 30% 11% 1	760
	11th to 20th	Night	22% 11% 34% 22% 9% 2	760
	21st to end	Night	32% 15% 27% 20% 6%	836
November	1st to 10th	Night	26% 15% 32% 21% 6% 1	866
	11th to 20th	Night	26% 19% 31% 18% 6% 1	900
	21st to end	Night	30% 19% 30% 18% 3	900
December	1st to 10th	Night	32% 16% 31% 18% 4	900
	11th to 20th	Night	30% 22% 31% 14% 3	900
	21st to end	Night	30% 18% 28% 20% 4	990

Page generated at 2025-07-18 02:09:59. Version ac07

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