Miscou Island
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Miscou Island clear sky chart from 2005-11-06 to 2024-02-05.

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	17% 8% 3 6% 6% 3 5% 5% 5% 7% 35%	77806
	Night	18% 10% 4 7% 6% 3 5% 4 5% 6% 31%	81074
Transparency	Day	48% 7% 14% 21% 10% 1	77496
	Night	52% 7% 13% 19% 9% 1	80919
Seeing	Day	21% 8% 28% 28% 13% 2	15575
	Night	23% 10% 28% 27% 10% 1	23283

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	14% 11% 5% 11% 8% 4 6% 5% 6% 5% 26%	2207
	11th to 20th	Day	12% 12% 4 6% 9% 4 6% 7% 8% 7% 25%	2210
	21st to end	Day	7% 7% 4 8% 8% 5% 6% 7% 7% 8% 34%	2947
February	1st to 10th	Day	12% 12% 5% 8% 7% 4 5% 5% 6% 5% 32%	1656
	11th to 20th	Day	14% 14% 4 7% 6% 4 5% 3 5% 5% 32%	1573
	21st to end	Day	10% 11% 4 6% 5% 4 5% 5% 5% 6% 39%	1332
March	1st to 10th	Day	15% 12% 4 7% 4 2 4 4 4 7% 38%	1921
	11th to 20th	Day	13% 8% 3 8% 6% 4 6% 5% 5% 7% 36%	1980
	21st to end	Day	16% 12% 4 7% 6% 3 4 4 4 5% 37%	2178
April	1st to 10th	Day	20% 10% 4 5% 4 2 4 4 5% 6% 35%	2150
	11th to 20th	Day	19% 8% 2 4 6% 3 4 5% 5% 6% 38%	2289
	21st to end	Day	24% 8% 3 6% 5% 3 4 4 4 6% 33%	2340
May	1st to 10th	Day	22% 9% 3 6% 6% 3 4 4 4 5% 33%	2469
	11th to 20th	Day	21% 8% 3 6% 5% 3 4 3 5% 7% 36%	2478
	21st to end	Day	19% 6% 2 5% 5% 3 4 4 6% 7% 39%	2805
June	1st to 10th	Day	26% 7% 3 6% 5% 3 4 4 4 6% 32%	2700
	11th to 20th	Day	18% 7% 2 5% 5% 2 4 4 5% 8% 39%	2700
	21st to end	Day	25% 7% 3 5% 4 3 4 5% 5% 7% 32%	2700
July	1st to 10th	Day	16% 6% 3 5% 5% 3 5% 6% 6% 9% 36%	2700
	11th to 20th	Day	11% 6% 3 6% 5% 3 5% 5% 6% 7% 43%	2700
	21st to end	Day	17% 6% 3 5% 4 2 5% 5% 6% 8% 38%	2803
August	1st to 10th	Day	15% 6% 2 5% 4 3 4 5% 6% 9% 41%	2359
	11th to 20th	Day	14% 6% 2 5% 6% 3 5% 5% 6% 7% 40%	2304
	21st to end	Day	13% 5% 3 4 4 3 4 5% 7% 9% 44%	2540
September	1st to 10th	Day	16% 6% 2 5% 6% 3 4 4 5% 5% 43%	2160
	11th to 20th	Day	17% 7% 2 5% 4 2 3 4 4 5% 46%	2080
	21st to end	Day	19% 5% 2 4 5% 2 4 3 5% 7% 44%	1935
October	1st to 10th	Day	16% 7% 3 5% 6% 3 5% 3 5% 6% 43%	1800
	11th to 20th	Day	19% 9% 3 5% 5% 3 4 5% 5% 7% 36%	1800
	21st to end	Day	22% 10% 2 6% 4 2 4 4 5% 7% 34%	1874
November	1st to 10th	Day	20% 9% 3 5% 5% 4 4 4 5% 6% 34%	1485
	11th to 20th	Day	20% 11% 5% 7% 5% 4 5% 6% 6% 5% 27%	1520
	21st to end	Day	18% 15% 6% 10% 6% 3 4 5% 5% 5% 23%	1520
December	1st to 10th	Day	22% 12% 4 10% 7% 4 5% 4 4 6% 22%	1492
	11th to 20th	Day	18% 12% 6% 11% 9% 4 6% 4 5% 5% 21%	1668
	21st to end	Day	18% 10% 5% 9% 7% 4 4 4 4 6% 28%	2431
January	1st to 10th	Night	12% 11% 5% 12% 10% 5% 6% 6% 6% 6% 23%	4748
	11th to 20th	Night	18% 10% 4 9% 10% 4 5% 5% 5% 6% 22%	4760
	21st to end	Night	9% 11% 5% 7% 8% 3 4 4 5% 7% 36%	4709
February	1st to 10th	Night	12% 13% 5% 8% 6% 4 5% 5% 5% 5% 32%	2399
	11th to 20th	Night	16% 13% 4 7% 6% 4 6% 3 4 5% 32%	2273
	21st to end	Night	14% 10% 5% 7% 6% 3 5% 5% 5% 6% 33%	1924
March	1st to 10th	Night	16% 11% 4 7% 5% 3 5% 4 4 5% 33%	2021
	11th to 20th	Night	15% 11% 5% 6% 6% 3 5% 5% 5% 6% 33%	1979
	21st to end	Night	17% 12% 5% 6% 6% 3 3 4 4 6% 34%	2178
April	1st to 10th	Night	23% 10% 4 6% 6% 3 4 4 4 5% 29%	1809
	11th to 20th	Night	20% 9% 3 6% 4 3 4 5% 5% 6% 36%	1618
	21st to end	Night	24% 10% 4 7% 4 3 4 3 3 5% 34%	1620
May	1st to 10th	Night	23% 10% 3 6% 6% 2 4 4 4 5% 33%	1490
	11th to 20th	Night	21% 7% 2 5% 5% 4 5% 5% 4 6% 37%	1416
	21st to end	Night	19% 7% 3 5% 6% 3 5% 5% 6% 7% 35%	1483
June	1st to 10th	Night	27% 8% 3 5% 5% 3 4 4 4 7% 30%	1260
	11th to 20th	Night	20% 7% 3 4 4 4 4 4 6% 7% 38%	1260
	21st to end	Night	25% 8% 4 5% 5% 3 5% 6% 6% 5% 29%	1260
July	1st to 10th	Night	17% 6% 3 5% 6% 4 4 6% 6% 9% 35%	1260
	11th to 20th	Night	15% 5% 3 5% 6% 4 7% 4 7% 8% 36%	1260
	21st to end	Night	16% 7% 3 5% 5% 3 5% 6% 8% 7% 34%	1494
August	1st to 10th	Night	15% 6% 2 6% 5% 3 6% 7% 6% 7% 37%	1577
	11th to 20th	Night	15% 8% 3 4 6% 3 5% 6% 6% 8% 37%	1596
	21st to end	Night	13% 6% 2 5% 4 3 5% 5% 7% 8% 42%	1815
September	1st to 10th	Night	18% 6% 3 5% 5% 3 4 4 4 7% 42%	1800
	11th to 20th	Night	18% 6% 2 4 4 3 4 3 5% 6% 46%	1879
	21st to end	Night	17% 5% 2 4 4 2 4 4 5% 6% 46%	2024
October	1st to 10th	Night	18% 7% 2 6% 4 3 4 5% 5% 6% 41%	2160
	11th to 20th	Night	20% 8% 3 6% 5% 3 4 4 5% 6% 36%	2160
	21st to end	Night	23% 10% 3 7% 5% 3 4 4 4 5% 33%	2479
November	1st to 10th	Night	21% 9% 4 6% 5% 3 4 4 5% 6% 33%	2593
	11th to 20th	Night	21% 12% 5% 7% 7% 3 5% 4 5% 6% 26%	2660
	21st to end	Night	22% 14% 5% 8% 6% 4 4 4 4 6% 23%	2660
December	1st to 10th	Night	23% 12% 6% 8% 7% 4 4 5% 5% 5% 21%	2683
	11th to 20th	Night	23% 13% 6% 10% 9% 4 5% 4 4 6% 17%	3531
	21st to end	Night	19% 12% 4 10% 7% 4 5% 4 5% 6% 25%	5236

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	54% 10% 9% 16% 9%	2208
	11th to 20th	Day	50% 19% 9% 11% 11%	2210
	21st to end	Day	40% 12% 16% 23% 9% 1	2947
February	1st to 10th	Day	50% 7% 13% 19% 10% 2	1656
	11th to 20th	Day	54% 5% 10% 19% 10% 1	1581
	21st to end	Day	44% 6% 10% 23% 13% 3	1332
March	1st to 10th	Day	48% 5% 12% 23% 11% 1	1925
	11th to 20th	Day	47% 7% 10% 21% 12% 4	1980
	21st to end	Day	51% 4 10% 19% 13% 3	2178
April	1st to 10th	Day	50% 5% 10% 18% 16% 2	2150
	11th to 20th	Day	46% 5% 11% 23% 14% 1	2289
	21st to end	Day	52% 5% 10% 16% 13% 3	2340
May	1st to 10th	Day	53% 5% 10% 19% 12% 1	2469
	11th to 20th	Day	48% 5% 12% 23% 11% 1	2482
	21st to end	Day	44% 7% 15% 21% 12% 1	2805
June	1st to 10th	Day	54% 6% 12% 20% 9%	2700
	11th to 20th	Day	44% 6% 13% 25% 11% 1	2700
	21st to end	Day	53% 6% 13% 19% 8%	2700
July	1st to 10th	Day	42% 9% 21% 20% 8%	2625
	11th to 20th	Day	38% 8% 17% 26% 11%	2619
	21st to end	Day	43% 9% 18% 23% 8%	2646
August	1st to 10th	Day	39% 9% 19% 26% 7%	2345
	11th to 20th	Day	41% 9% 21% 22% 7% 1	2304
	21st to end	Day	36% 7% 19% 29% 9%	2540
September	1st to 10th	Day	41% 7% 15% 25% 11%	2160
	11th to 20th	Day	41% 6% 13% 26% 13%	2080
	21st to end	Day	41% 6% 13% 27% 13% 1	1935
October	1st to 10th	Day	42% 5% 15% 26% 9% 2	1800
	11th to 20th	Day	48% 6% 18% 21% 7% 1	1800
	21st to end	Day	51% 6% 14% 20% 8%	1874
November	1st to 10th	Day	52% 7% 13% 19% 8% 1	1485
	11th to 20th	Day	56% 8% 14% 14% 7%	1520
	21st to end	Day	62% 8% 13% 11% 5%	1520
December	1st to 10th	Day	64% 9% 12% 10% 5%	1492
	11th to 20th	Day	65% 7% 11% 11% 6%	1668
	21st to end	Day	56% 7% 14% 15% 6% 1	2431
January	1st to 10th	Night	55% 10% 17% 14% 3	4748
	11th to 20th	Night	58% 10% 11% 14% 6% 1	4760
	21st to end	Night	45% 8% 16% 20% 11% 1	4709
February	1st to 10th	Night	53% 6% 11% 16% 12% 2	2399
	11th to 20th	Night	55% 5% 11% 18% 10% 1	2276
	21st to end	Night	50% 5% 9% 20% 14% 2	1924
March	1st to 10th	Night	53% 5% 8% 20% 12% 1	2030
	11th to 20th	Night	51% 5% 10% 21% 11% 2	1980
	21st to end	Night	52% 5% 10% 17% 13% 3	2178
April	1st to 10th	Night	58% 5% 9% 13% 14% 2	1809
	11th to 20th	Night	48% 4 10% 21% 15% 2	1618
	21st to end	Night	54% 5% 8% 15% 16% 2	1620
May	1st to 10th	Night	53% 5% 8% 20% 13% 1	1490
	11th to 20th	Night	48% 6% 11% 23% 10% 1	1417
	21st to end	Night	48% 7% 12% 22% 10% 1	1484
June	1st to 10th	Night	55% 5% 11% 21% 8%	1260
	11th to 20th	Night	46% 6% 12% 23% 12% 1	1260
	21st to end	Night	56% 8% 13% 14% 8% 1	1260
July	1st to 10th	Night	45% 7% 17% 23% 7%	1225
	11th to 20th	Night	43% 8% 14% 26% 8% 1	1218
	21st to end	Night	46% 8% 16% 21% 9%	1411
August	1st to 10th	Night	43% 10% 17% 22% 8%	1566
	11th to 20th	Night	44% 9% 17% 24% 7%	1596
	21st to end	Night	39% 7% 18% 28% 9%	1815
September	1st to 10th	Night	42% 7% 14% 28% 9% 1	1800
	11th to 20th	Night	39% 6% 13% 28% 13%	1879
	21st to end	Night	38% 7% 13% 27% 14% 1	2024
October	1st to 10th	Night	43% 5% 12% 25% 13% 1	2160
	11th to 20th	Night	48% 6% 15% 24% 7%	2160
	21st to end	Night	55% 6% 12% 19% 8%	2479
November	1st to 10th	Night	52% 5% 14% 19% 8% 1	2593
	11th to 20th	Night	57% 7% 13% 15% 7%	2660
	21st to end	Night	63% 7% 15% 10% 5%	2660
December	1st to 10th	Night	64% 8% 11% 13% 4	2683
	11th to 20th	Night	69% 6% 8% 13% 5%	3532
	21st to end	Night	58% 9% 14% 14% 5%	5236

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% 13% 36% 18% 8%	180
	11th to 20th	Day	29% 18% 27% 16% 9% 1	180
	21st to end	Day	14% 12% 34% 27% 12% 2	354
February	1st to 10th	Day	22% 12% 34% 25% 7% 1	352
	11th to 20th	Day	18% 13% 38% 22% 8% 1	336
	21st to end	Day	16% 10% 35% 29% 10% 1	280
March	1st to 10th	Day	20% 10% 34% 28% 6% 2	410
	11th to 20th	Day	16% 12% 31% 26% 13% 3	420
	21st to end	Day	21% 10% 32% 26% 8% 3	462
April	1st to 10th	Day	28% 14% 27% 23% 7%	420
	11th to 20th	Day	22% 8% 33% 26% 10% 1	412
	21st to end	Day	27% 7% 25% 26% 12% 2	420
May	1st to 10th	Day	27% 5% 26% 29% 11% 3	552
	11th to 20th	Day	23% 6% 25% 24% 19% 4	624
	21st to end	Day	23% 5% 30% 29% 11% 2	680
June	1st to 10th	Day	29% 4 23% 28% 11% 4	630
	11th to 20th	Day	20% 4 22% 34% 17% 3	630
	21st to end	Day	26% 3 21% 31% 15% 2	630
July	1st to 10th	Day	19% 4 25% 34% 15% 4	620
	11th to 20th	Day	14% 3 22% 39% 20% 3	618
	21st to end	Day	19% 4 17% 35% 21% 5%	685
August	1st to 10th	Day	12% 5% 20% 35% 24% 4	478
	11th to 20th	Day	16% 4 19% 35% 22% 4	439
	21st to end	Day	14% 5% 19% 36% 20% 5%	495
September	1st to 10th	Day	17% 4 28% 33% 15% 2	450
	11th to 20th	Day	21% 8% 26% 31% 12% 3	450
	21st to end	Day	21% 8% 32% 25% 11% 3	427
October	1st to 10th	Day	16% 8% 31% 28% 15% 2	360
	11th to 20th	Day	23% 10% 33% 19% 13% 3	360
	21st to end	Day	27% 13% 31% 21% 8% 1	396
November	1st to 10th	Day	21% 15% 34% 22% 7% 1	365
	11th to 20th	Day	27% 14% 30% 20% 6% 2	370
	21st to end	Day	26% 16% 35% 18% 4	370
December	1st to 10th	Day	26% 14% 33% 20% 7% 1	342
	11th to 20th	Day	22% 25% 30% 19% 4	180
	21st to end	Day	21% 21% 35% 17% 6%	198
January	1st to 10th	Night	24% 12% 36% 21% 6% 1	850
	11th to 20th	Night	22% 13% 34% 25% 6%	850
	21st to end	Night	19% 10% 36% 23% 10% 1	859
February	1st to 10th	Night	18% 12% 36% 26% 7% 1	739
	11th to 20th	Night	24% 10% 35% 24% 6% 2	703
	21st to end	Night	20% 8% 31% 27% 12% 2	592
March	1st to 10th	Night	20% 9% 34% 30% 7% 1	720
	11th to 20th	Night	19% 9% 33% 28% 10% 1	720
	21st to end	Night	21% 10% 30% 29% 9% 1	792
April	1st to 10th	Night	26% 10% 27% 28% 8% 1	549
	11th to 20th	Night	23% 6% 31% 28% 11% 1	534
	21st to end	Night	26% 9% 25% 27% 11% 2	540
May	1st to 10th	Night	28% 5% 21% 30% 13% 3	540
	11th to 20th	Night	23% 4 24% 30% 15% 3	532
	21st to end	Night	20% 5% 30% 33% 11% 2	516
June	1st to 10th	Night	29% 4 18% 33% 14% 1	360
	11th to 20th	Night	23% 3 20% 30% 20% 3	360
	21st to end	Night	26% 3 15% 38% 16% 2	360
July	1st to 10th	Night	18% 3 18% 38% 20% 3	350
	11th to 20th	Night	16% 5% 16% 43% 18% 2	348
	21st to end	Night	19% 4 18% 38% 20% 2	511
August	1st to 10th	Night	17% 3 17% 40% 21% 2	538
	11th to 20th	Night	18% 2 14% 41% 22% 2	532
	21st to end	Night	14% 3 20% 37% 22% 4	594
September	1st to 10th	Night	21% 6% 25% 34% 13% 2	540
	11th to 20th	Night	19% 9% 21% 35% 15% 1	619
	21st to end	Night	20% 7% 30% 30% 12%	720
October	1st to 10th	Night	20% 7% 32% 28% 11% 1	720
	11th to 20th	Night	23% 10% 29% 26% 11% 1	720
	21st to end	Night	27% 14% 29% 23% 7% 1	810
November	1st to 10th	Night	26% 15% 30% 21% 7% 1	830
	11th to 20th	Night	26% 16% 29% 20% 6% 2	850
	21st to end	Night	28% 16% 29% 20% 5%	850
December	1st to 10th	Night	29% 16% 32% 19% 4	850
	11th to 20th	Night	27% 19% 33% 16% 5% 1	850
	21st to end	Night	27% 16% 32% 18% 6% 1	935

Page generated at 2024-02-02 06:20:28. Version ac07

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