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 2025-02-06.

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% 9% 3 8% 5% 4 4 4 5% 6% 35%	108251
	Night	17% 11% 4 9% 5% 5% 4 3 5% 6% 31%	110146
Transparency	Day	48% 7% 14% 21% 9% 1	111777
	Night	52% 7% 13% 19% 8% 1	114775
Seeing	Day	21% 9% 28% 28% 13% 2	16932
	Night	23% 10% 28% 27% 10% 1	24608

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	17% 19% 6% 11% 5% 4 4 4 5% 4 20%	3157
	11th to 20th	Day	11% 15% 7% 15% 6% 5% 6% 4 6% 6% 19%	3134
	21st to end	Day	5% 6% 4 10% 8% 8% 9% 5% 6% 7% 32%	4235
February	1st to 10th	Day	11% 13% 4 9% 6% 6% 4 4 6% 5% 33%	1755
	11th to 20th	Day	13% 14% 4 8% 6% 5% 4 3 5% 5% 32%	1663
	21st to end	Day	10% 11% 4 6% 6% 5% 4 4 5% 6% 38%	1413
March	1st to 10th	Day	15% 13% 4 9% 4 4 5% 3 5% 6% 33%	3351
	11th to 20th	Day	16% 14% 4 11% 6% 5% 5% 3 4 5% 26%	3480
	21st to end	Day	24% 11% 3 7% 4 4 4 3 3 5% 32%	3816
April	1st to 10th	Day	20% 11% 3 6% 4 3 3 4 5% 5% 36%	2270
	11th to 20th	Day	19% 9% 2 6% 5% 4 4 4 5% 6% 37%	2418
	21st to end	Day	23% 8% 3 7% 4 4 3 3 5% 6% 33%	2470
May	1st to 10th	Day	19% 10% 4 7% 5% 4 4 4 5% 7% 30%	4346
	11th to 20th	Day	17% 8% 2 7% 4 4 4 3 5% 7% 38%	4398
	21st to end	Day	19% 9% 3 7% 5% 4 4 3 6% 8% 32%	4987
June	1st to 10th	Day	25% 8% 2 7% 4 4 4 3 5% 6% 31%	2850
	11th to 20th	Day	17% 8% 2 6% 5% 4 4 3 5% 8% 39%	2850
	21st to end	Day	24% 8% 3 6% 4 4 4 4 6% 6% 31%	2850
July	1st to 10th	Day	13% 6% 3 7% 4 5% 5% 4 6% 8% 39%	4760
	11th to 20th	Day	11% 7% 3 7% 5% 5% 5% 4 7% 7% 40%	4760
	21st to end	Day	12% 5% 2 5% 3 3 4 4 6% 8% 49%	4915
August	1st to 10th	Day	14% 6% 2 6% 4 5% 5% 4 6% 8% 40%	4151
	11th to 20th	Day	13% 5% 2 6% 5% 5% 4 4 6% 8% 43%	4045
	21st to end	Day	14% 5% 2 5% 3 3 4 3 6% 8% 49%	4470
September	1st to 10th	Day	16% 6% 2 6% 4 4 4 3 6% 5% 43%	2280
	11th to 20th	Day	17% 7% 3 5% 3 3 3 3 4 5% 48%	2195
	21st to end	Day	19% 6% 2 5% 4 3 3 3 5% 7% 43%	2042
October	1st to 10th	Day	16% 7% 3 6% 5% 4 4 3 5% 6% 42%	1900
	11th to 20th	Day	18% 9% 3 7% 4 4 4 4 5% 7% 35%	1900
	21st to end	Day	22% 10% 2 7% 4 3 4 3 5% 6% 34%	1977
November	1st to 10th	Day	20% 10% 3 6% 5% 5% 4 3 5% 6% 33%	1565
	11th to 20th	Day	21% 12% 5% 8% 4 5% 5% 4 6% 5% 26%	1600
	21st to end	Day	19% 16% 5% 10% 6% 4 3 4 5% 5% 22%	1600
December	1st to 10th	Day	16% 14% 6% 11% 7% 6% 5% 3 5% 5% 22%	2554
	11th to 20th	Day	19% 12% 5% 13% 6% 4 4 3 4 5% 26%	2618
	21st to end	Day	17% 12% 6% 12% 5% 4 4 3 4 6% 27%	3476
January	1st to 10th	Night	18% 18% 5% 12% 7% 5% 5% 3 4 4 18%	6808
	11th to 20th	Night	16% 14% 6% 14% 7% 5% 4 3 5% 6% 19%	6771
	21st to end	Night	6% 9% 5% 9% 7% 8% 7% 4 5% 6% 34%	6723
February	1st to 10th	Night	12% 14% 4 8% 6% 5% 4 4 5% 5% 32%	2536
	11th to 20th	Night	15% 13% 4 8% 5% 6% 4 3 4 5% 32%	2403
	21st to end	Night	14% 11% 4 7% 6% 5% 4 4 5% 5% 34%	2041
March	1st to 10th	Night	13% 12% 4 10% 6% 7% 5% 4 5% 5% 31%	3484
	11th to 20th	Night	24% 16% 5% 10% 5% 5% 4 3 4 5% 20%	3479
	21st to end	Night	27% 12% 3 6% 5% 3 3 3 4 7% 29%	3816
April	1st to 10th	Night	23% 11% 4 7% 5% 4 4 3 4 5% 30%	1909
	11th to 20th	Night	20% 9% 3 6% 3 3 4 4 6% 6% 35%	1709
	21st to end	Night	23% 10% 3 7% 4 4 3 3 4 5% 34%	1710
May	1st to 10th	Night	23% 11% 4 8% 5% 4 4 3 4 5% 28%	2601
	11th to 20th	Night	14% 7% 3 6% 4 4 5% 4 6% 7% 39%	2506
	21st to end	Night	16% 10% 4 8% 6% 6% 5% 4 7% 7% 27%	2626
June	1st to 10th	Night	26% 9% 3 7% 4 4 3 4 4 7% 29%	1330
	11th to 20th	Night	19% 8% 2 5% 3 5% 3 4 7% 7% 37%	1330
	21st to end	Night	24% 8% 3 6% 5% 4 5% 5% 6% 5% 29%	1330
July	1st to 10th	Night	14% 7% 3 6% 5% 5% 4 4 6% 8% 39%	2210
	11th to 20th	Night	14% 7% 2 7% 5% 5% 6% 4 7% 7% 36%	2210
	21st to end	Night	11% 6% 2 5% 4 4 4 4 7% 7% 46%	2615
August	1st to 10th	Night	15% 9% 3 9% 6% 5% 6% 5% 5% 7% 31%	2777
	11th to 20th	Night	11% 8% 2 6% 5% 4 5% 4 6% 7% 40%	2782
	21st to end	Night	13% 4 2 5% 3 4 4 3 6% 8% 48%	3185
September	1st to 10th	Night	18% 7% 2 6% 4 5% 4 3 5% 7% 42%	1900
	11th to 20th	Night	17% 5% 2 5% 4 3 4 2 5% 6% 47%	1984
	21st to end	Night	17% 5% 2 5% 3 3 4 3 5% 6% 46%	2137
October	1st to 10th	Night	18% 7% 2 7% 4 4 4 4 5% 6% 41%	2280
	11th to 20th	Night	20% 8% 3 6% 4 4 4 3 5% 6% 37%	2280
	21st to end	Night	23% 10% 2 8% 4 4 4 3 4 5% 33%	2617
November	1st to 10th	Night	21% 9% 4 7% 4 4 4 3 5% 6% 34%	2733
	11th to 20th	Night	22% 13% 4 8% 5% 4 4 3 5% 6% 25%	2800
	21st to end	Night	23% 15% 5% 9% 5% 5% 3 3 5% 6% 22%	2800
December	1st to 10th	Night	15% 13% 7% 10% 6% 5% 4 3 6% 5% 25%	4631
	11th to 20th	Night	20% 11% 4 10% 6% 4 4 3 4 5% 28%	5591
	21st to end	Night	19% 14% 5% 12% 5% 5% 4 3 4 6% 24%	7502

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	64% 8% 10% 12% 7%	3158
	11th to 20th	Day	62% 15% 8% 8% 8%	3160
	21st to end	Day	44% 11% 13% 22% 10%	4235
February	1st to 10th	Day	49% 6% 13% 19% 11% 2	1755
	11th to 20th	Day	53% 6% 10% 20% 10% 1	1671
	21st to end	Day	45% 6% 10% 24% 13% 3	1413
March	1st to 10th	Day	49% 8% 14% 21% 7% 1	3355
	11th to 20th	Day	60% 6% 9% 16% 7% 2	3480
	21st to end	Day	55% 5% 7% 20% 11% 2	3816
April	1st to 10th	Day	49% 5% 10% 19% 16% 2	2270
	11th to 20th	Day	46% 6% 12% 23% 13% 1	2418
	21st to end	Day	51% 5% 10% 16% 14% 3	2470
May	1st to 10th	Day	51% 8% 12% 21% 8%	4361
	11th to 20th	Day	45% 5% 16% 26% 8% 1	4402
	21st to end	Day	48% 9% 13% 20% 10% 1	4987
June	1st to 10th	Day	53% 6% 12% 19% 9%	2850
	11th to 20th	Day	43% 6% 14% 24% 11% 1	2850
	21st to end	Day	53% 6% 13% 19% 8%	2850
July	1st to 10th	Day	41% 7% 20% 22% 10%	4685
	11th to 20th	Day	41% 7% 18% 26% 8%	4679
	21st to end	Day	33% 8% 25% 24% 10%	4758
August	1st to 10th	Day	41% 7% 19% 23% 9%	4137
	11th to 20th	Day	39% 7% 20% 23% 10% 1	4084
	21st to end	Day	34% 5% 19% 28% 13% 1	4470
September	1st to 10th	Day	41% 7% 15% 26% 12%	2280
	11th to 20th	Day	40% 6% 15% 26% 12%	2195
	21st to end	Day	42% 6% 13% 27% 12% 1	2042
October	1st to 10th	Day	44% 5% 15% 27% 8% 1	3160
	11th to 20th	Day	48% 6% 15% 24% 7%	3140
	21st to end	Day	42% 5% 17% 24% 11%	3233
November	1st to 10th	Day	52% 7% 13% 19% 8% 1	1565
	11th to 20th	Day	57% 8% 14% 14% 8%	1600
	21st to end	Day	63% 8% 13% 11% 5%	1600
December	1st to 10th	Day	61% 9% 11% 15% 3	2554
	11th to 20th	Day	61% 6% 12% 15% 6%	2618
	21st to end	Day	58% 7% 11% 18% 5% 1	3476
January	1st to 10th	Night	65% 8% 13% 12% 2	6808
	11th to 20th	Night	62% 9% 12% 12% 5%	6820
	21st to end	Night	47% 8% 13% 21% 10% 1	6723
February	1st to 10th	Night	52% 5% 11% 17% 13% 2	2536
	11th to 20th	Night	55% 5% 11% 18% 11% 1	2406
	21st to end	Night	49% 5% 9% 21% 13% 2	2041
March	1st to 10th	Night	53% 7% 10% 20% 9% 1	3493
	11th to 20th	Night	66% 5% 7% 13% 6% 1	3480
	21st to end	Night	57% 5% 7% 17% 12% 2	3816
April	1st to 10th	Night	56% 5% 9% 14% 14% 2	1909
	11th to 20th	Night	48% 4 10% 21% 15% 2	1709
	21st to end	Night	53% 5% 8% 16% 16% 2	1710
May	1st to 10th	Night	58% 6% 8% 18% 9% 1	2606
	11th to 20th	Night	42% 8% 15% 27% 7% 1	2507
	21st to end	Night	53% 9% 12% 18% 8% 1	2627
June	1st to 10th	Night	56% 5% 11% 21% 8%	1330
	11th to 20th	Night	46% 6% 13% 22% 12% 2	1330
	21st to end	Night	56% 8% 13% 15% 8% 1	1330
July	1st to 10th	Night	43% 6% 18% 19% 13%	2175
	11th to 20th	Night	46% 7% 13% 28% 5%	2168
	21st to end	Night	36% 8% 23% 23% 9%	2532
August	1st to 10th	Night	51% 9% 14% 19% 7%	2766
	11th to 20th	Night	42% 7% 17% 25% 8%	2809
	21st to end	Night	34% 5% 19% 28% 14%	3184
September	1st to 10th	Night	42% 6% 14% 28% 9% 1	1900
	11th to 20th	Night	38% 6% 15% 28% 12%	1984
	21st to end	Night	38% 7% 14% 27% 14% 1	2137
October	1st to 10th	Night	47% 5% 12% 28% 8% 1	3800
	11th to 20th	Night	40% 5% 12% 32% 10%	3779
	21st to end	Night	47% 5% 14% 22% 11%	4302
November	1st to 10th	Night	52% 5% 14% 19% 8% 1	2733
	11th to 20th	Night	58% 7% 13% 15% 7%	2800
	21st to end	Night	64% 7% 14% 10% 5%	2800
December	1st to 10th	Night	56% 9% 12% 18% 5%	4631
	11th to 20th	Night	59% 5% 9% 20% 6% 1	5592
	21st to end	Night	60% 8% 12% 15% 5%	7502

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	27% 14% 34% 19% 7%	200
	11th to 20th	Day	29% 17% 25% 18% 10% 2	200
	21st to end	Day	13% 12% 36% 27% 11% 2	385
February	1st to 10th	Day	21% 12% 34% 24% 8% 2	385
	11th to 20th	Day	17% 13% 39% 22% 7% 1	366
	21st to end	Day	18% 10% 35% 27% 9% 1	307
March	1st to 10th	Day	19% 11% 35% 28% 6% 2	449
	11th to 20th	Day	16% 12% 30% 27% 13% 2	460
	21st to end	Day	23% 11% 31% 25% 7% 3	506
April	1st to 10th	Day	27% 14% 28% 23% 7%	460
	11th to 20th	Day	21% 9% 33% 25% 10% 2	452
	21st to end	Day	26% 8% 27% 25% 11% 2	460
May	1st to 10th	Day	26% 6% 26% 28% 12% 3	600
	11th to 20th	Day	22% 5% 25% 25% 20% 4	674
	21st to end	Day	22% 6% 30% 30% 11% 2	735
June	1st to 10th	Day	28% 4 24% 29% 12% 3	680
	11th to 20th	Day	19% 4 23% 34% 16% 3	680
	21st to end	Day	26% 4 23% 30% 14% 2	680
July	1st to 10th	Day	18% 4 26% 33% 14% 4	670
	11th to 20th	Day	14% 4 22% 39% 19% 3	668
	21st to end	Day	18% 4 18% 35% 21% 4	740
August	1st to 10th	Day	12% 6% 21% 34% 23% 3	519
	11th to 20th	Day	16% 4 20% 35% 21% 4	479
	21st to end	Day	14% 5% 20% 35% 20% 5%	539
September	1st to 10th	Day	17% 5% 29% 33% 14% 2	490
	11th to 20th	Day	20% 7% 26% 31% 12% 3	490
	21st to end	Day	20% 8% 31% 25% 12% 3	464
October	1st to 10th	Day	17% 8% 30% 28% 15% 2	390
	11th to 20th	Day	23% 11% 33% 19% 12% 2	390
	21st to end	Day	26% 13% 33% 21% 7% 1	429
November	1st to 10th	Day	21% 16% 34% 22% 7% 1	395
	11th to 20th	Day	29% 15% 29% 20% 7% 2	400
	21st to end	Day	29% 16% 34% 17% 4	400
December	1st to 10th	Day	25% 14% 34% 19% 7% 1	370
	11th to 20th	Day	24% 24% 29% 20% 4	200
	21st to end	Day	20% 20% 35% 20% 6%	220
January	1st to 10th	Night	25% 13% 35% 21% 6% 1	900
	11th to 20th	Night	22% 13% 33% 25% 7%	900
	21st to end	Night	19% 12% 36% 22% 9% 1	905
February	1st to 10th	Night	18% 12% 36% 24% 7% 2	781
	11th to 20th	Night	23% 12% 34% 24% 6% 2	743
	21st to end	Night	20% 9% 32% 27% 11% 1	628
March	1st to 10th	Night	19% 10% 34% 29% 6% 1	760
	11th to 20th	Night	20% 9% 33% 27% 10% 1	760
	21st to end	Night	23% 10% 29% 29% 8% 1	836
April	1st to 10th	Night	26% 10% 27% 28% 8% 1	579
	11th to 20th	Night	23% 6% 31% 27% 12% 1	564
	21st to end	Night	25% 10% 25% 27% 11% 2	570
May	1st to 10th	Night	28% 5% 21% 30% 13% 3	570
	11th to 20th	Night	22% 4 23% 31% 17% 3	562
	21st to end	Night	19% 6% 30% 33% 11% 2	545
June	1st to 10th	Night	29% 4 18% 32% 15% 1	380
	11th to 20th	Night	22% 3 22% 30% 20% 3	380
	21st to end	Night	26% 3 16% 38% 15% 2	380
July	1st to 10th	Night	18% 4 18% 38% 19% 3	370
	11th to 20th	Night	15% 5% 17% 43% 18% 2	368
	21st to end	Night	18% 4 19% 38% 19% 2	540
August	1st to 10th	Night	18% 3 17% 40% 20% 2	568
	11th to 20th	Night	18% 3 15% 41% 21% 2	562
	21st to end	Night	14% 4 20% 36% 23% 4	627
September	1st to 10th	Night	21% 6% 25% 34% 12% 2	570
	11th to 20th	Night	18% 8% 21% 35% 16% 1	654
	21st to end	Night	20% 7% 29% 30% 14% 1	760
October	1st to 10th	Night	20% 7% 32% 28% 11% 1	760
	11th to 20th	Night	23% 11% 29% 26% 10% 1	760
	21st to end	Night	26% 15% 29% 23% 6% 1	856
November	1st to 10th	Night	26% 16% 30% 21% 6% 1	880
	11th to 20th	Night	27% 16% 29% 20% 6% 2	900
	21st to end	Night	30% 16% 29% 19% 5%	900
December	1st to 10th	Night	27% 17% 32% 19% 5%	900
	11th to 20th	Night	27% 20% 33% 15% 5% 1	900
	21st to end	Night	27% 15% 32% 18% 6% 1	990

Page generated at 2025-02-03 04:05:51. Version ac07

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