Saint-Michel-des-Saints
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Saint-Michel-des-Saints clear sky chart from 2005-11-06 to 2026-03-18.

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	15% 12% 4 10% 6% 5% 5% 4 5% 6% 27%	131314
	Night	14% 13% 5% 12% 7% 5% 5% 3 5% 6% 25%	130185
Transparency	Day	56% 6% 11% 17% 9% 1	134746
	Night	59% 6% 11% 16% 8% 1	134840
Seeing	Day	25% 19% 31% 17% 6% 2	16070
	Night	23% 16% 31% 22% 8% 1	25158

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	10% 17% 7% 18% 8% 7% 7% 3 4 4 15%	4661
	11th to 20th	Day	6% 17% 9% 20% 11% 5% 4 3 4 4 16%	4650
	21st to end	Day	5% 9% 7% 18% 8% 7% 6% 5% 6% 7% 21%	5124
February	1st to 10th	Day	8% 17% 6% 15% 10% 7% 4 2 5% 5% 21%	1817
	11th to 20th	Day	9% 17% 6% 13% 7% 7% 5% 4 4 5% 24%	1915
	21st to end	Day	12% 18% 6% 12% 8% 6% 5% 2 4 4 23%	1730
March	1st to 10th	Day	14% 20% 6% 14% 7% 5% 4 3 4 3 21%	4576
	11th to 20th	Day	9% 17% 6% 12% 6% 5% 5% 4 5% 5% 26%	4790
	21st to end	Day	12% 17% 5% 11% 5% 4 4 3 4 5% 31%	5960
April	1st to 10th	Day	17% 19% 5% 10% 5% 4 3 3 4 5% 26%	2400
	11th to 20th	Day	21% 12% 4 7% 4 4 4 3 4 4 33%	2374
	21st to end	Day	20% 14% 4 8% 5% 4 4 3 4 4 29%	2591
May	1st to 10th	Day	22% 14% 3 8% 5% 5% 4 3 5% 6% 24%	6346
	11th to 20th	Day	21% 8% 3 8% 5% 5% 5% 4 5% 6% 29%	6318
	21st to end	Day	21% 11% 3 8% 5% 5% 4 4 4 5% 28%	6949
June	1st to 10th	Day	24% 9% 3 8% 5% 4 5% 3 6% 6% 28%	2800
	11th to 20th	Day	18% 7% 3 7% 6% 5% 5% 4 6% 9% 31%	2800
	21st to end	Day	22% 10% 3 8% 6% 5% 5% 4 6% 7% 24%	2800
July	1st to 10th	Day	17% 9% 3 9% 6% 6% 5% 5% 7% 8% 25%	6360
	11th to 20th	Day	11% 7% 3 7% 5% 6% 6% 5% 7% 9% 34%	6360
	21st to end	Day	10% 7% 2 7% 4 5% 6% 5% 6% 9% 40%	6926
August	1st to 10th	Day	15% 7% 3 8% 5% 5% 6% 5% 7% 8% 29%	4563
	11th to 20th	Day	17% 7% 4 8% 5% 5% 5% 4 6% 7% 33%	4226
	21st to end	Day	15% 7% 3 8% 5% 5% 5% 4 6% 8% 34%	4312
September	1st to 10th	Day	16% 7% 3 6% 4 5% 4 4 7% 8% 38%	2400
	11th to 20th	Day	15% 8% 3 6% 4 4 4 3 5% 6% 40%	2330
	21st to end	Day	21% 9% 2 6% 4 4 4 3 4 7% 36%	2200
October	1st to 10th	Day	20% 12% 3 8% 4 5% 3 3 5% 6% 31%	2040
	11th to 20th	Day	20% 15% 4 10% 6% 4 5% 3 4 4 24%	1948
	21st to end	Day	23% 16% 5% 10% 5% 5% 4 2 4 4 22%	1980
November	1st to 10th	Day	15% 18% 5% 9% 5% 5% 4 3 4 4 27%	1851
	11th to 20th	Day	15% 19% 5% 12% 6% 5% 4 3 4 5% 20%	1743
	21st to end	Day	16% 21% 7% 14% 7% 4 4 3 3 4 17%	1680
December	1st to 10th	Day	15% 21% 8% 16% 8% 6% 4 3 3 4 13%	2680
	11th to 20th	Day	14% 16% 5% 15% 8% 6% 5% 3 5% 5% 18%	3066
	21st to end	Day	14% 16% 8% 15% 8% 6% 4 3 4 5% 18%	4048
January	1st to 10th	Night	9% 18% 9% 19% 8% 6% 5% 4 3 4 15%	8234
	11th to 20th	Night	7% 16% 8% 21% 13% 8% 6% 3 3 4 11%	8235
	21st to end	Night	4 10% 7% 18% 11% 8% 7% 4 7% 6% 18%	9057
February	1st to 10th	Night	8% 14% 6% 13% 10% 7% 5% 6% 5% 5% 21%	2800
	11th to 20th	Night	8% 16% 6% 13% 8% 8% 6% 4 4 5% 21%	2590
	21st to end	Night	11% 15% 5% 10% 8% 6% 6% 3 5% 5% 26%	2076
March	1st to 10th	Night	17% 17% 5% 11% 8% 4 5% 3 4 4 21%	5484
	11th to 20th	Night	11% 16% 5% 12% 6% 5% 5% 3 5% 6% 25%	5321
	21st to end	Night	14% 12% 5% 11% 6% 6% 5% 4 5% 5% 27%	4972
April	1st to 10th	Night	20% 14% 4 10% 5% 4 4 3 4 5% 26%	2000
	11th to 20th	Night	16% 12% 4 7% 5% 4 4 3 4 7% 34%	1975
	21st to end	Night	20% 12% 4 7% 4 3 4 3 4 5% 34%	1824
May	1st to 10th	Night	21% 11% 3 8% 6% 5% 4 4 5% 7% 26%	3594
	11th to 20th	Night	21% 9% 3 7% 5% 4 4 4 5% 6% 32%	3575
	21st to end	Night	22% 9% 3 8% 6% 5% 5% 4 5% 7% 27%	3926
June	1st to 10th	Night	20% 9% 2 7% 4 5% 4 4 6% 8% 31%	1600
	11th to 20th	Night	16% 8% 3 7% 5% 5% 5% 3 5% 7% 36%	1600
	21st to end	Night	19% 7% 3 6% 5% 4 4 4 5% 7% 35%	1600
July	1st to 10th	Night	12% 8% 3 9% 6% 6% 6% 5% 7% 9% 29%	3600
	11th to 20th	Night	13% 7% 2 6% 5% 5% 5% 4 6% 9% 39%	3600
	21st to end	Night	9% 6% 2 6% 4 4 5% 4 6% 8% 45%	3926
August	1st to 10th	Night	11% 8% 3 8% 5% 5% 5% 4 6% 7% 38%	2586
	11th to 20th	Night	16% 8% 4 7% 5% 5% 4 3 6% 6% 36%	2788
	21st to end	Night	17% 9% 3 7% 5% 5% 4 4 5% 7% 36%	3586
September	1st to 10th	Night	15% 8% 2 6% 4 3 4 3 4 8% 43%	2000
	11th to 20th	Night	16% 6% 2 5% 4 4 4 3 5% 6% 44%	2070
	21st to end	Night	16% 10% 3 6% 4 4 4 3 5% 6% 41%	2200
October	1st to 10th	Night	16% 10% 3 7% 4 4 4 3 4 6% 39%	2356
	11th to 20th	Night	19% 16% 4 8% 4 4 4 3 4 6% 28%	2450
	21st to end	Night	22% 15% 4 9% 5% 4 4 3 5% 6% 22%	2860
November	1st to 10th	Night	15% 16% 6% 9% 5% 5% 5% 3 5% 6% 25%	2667
	11th to 20th	Night	14% 14% 7% 14% 7% 6% 4 3 5% 6% 22%	2875
	21st to end	Night	17% 20% 7% 12% 7% 4 4 3 4 4 17%	2940
December	1st to 10th	Night	13% 18% 8% 17% 10% 6% 5% 3 5% 4 11%	4720
	11th to 20th	Night	17% 17% 6% 13% 9% 5% 4 3 3 4 18%	5348
	21st to end	Night	15% 19% 6% 13% 7% 4 5% 4 4 6% 16%	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	72% 5% 7% 11% 4	4662
	11th to 20th	Day	71% 4 5% 10% 9% 1	4680
	21st to end	Day	61% 5% 5% 14% 14% 1	5124
February	1st to 10th	Day	65% 3 6% 15% 8% 2	1817
	11th to 20th	Day	62% 5% 8% 14% 10% 1	1924
	21st to end	Day	65% 4 6% 13% 9% 2	1730
March	1st to 10th	Day	67% 5% 5% 9% 11% 3	4579
	11th to 20th	Day	57% 6% 13% 11% 11% 2	4790
	21st to end	Day	54% 5% 7% 16% 16% 2	5960
April	1st to 10th	Day	61% 5% 8% 14% 10% 2	2400
	11th to 20th	Day	54% 5% 8% 19% 12% 2	2374
	21st to end	Day	57% 6% 8% 14% 12% 2	2591
May	1st to 10th	Day	58% 6% 9% 16% 10% 1	6357
	11th to 20th	Day	51% 10% 14% 16% 7% 1	6322
	21st to end	Day	55% 7% 9% 14% 13% 2	6949
June	1st to 10th	Day	55% 8% 10% 16% 10% 1	2800
	11th to 20th	Day	48% 9% 13% 19% 10% 2	2800
	21st to end	Day	58% 8% 11% 15% 8%	2800
July	1st to 10th	Day	54% 5% 13% 23% 5%	6290
	11th to 20th	Day	43% 7% 18% 27% 5%	6285
	21st to end	Day	40% 6% 17% 28% 9%	6728
August	1st to 10th	Day	50% 8% 16% 20% 6%	4549
	11th to 20th	Day	48% 7% 17% 24% 5%	4268
	21st to end	Day	47% 7% 12% 21% 12% 1	4312
September	1st to 10th	Day	42% 8% 16% 25% 10% 1	2400
	11th to 20th	Day	42% 7% 15% 27% 9% 1	2330
	21st to end	Day	48% 7% 12% 23% 10%	2200
October	1st to 10th	Day	53% 5% 11% 25% 6%	3326
	11th to 20th	Day	57% 5% 12% 20% 5%	3151
	21st to end	Day	59% 4 18% 13% 5% 1	3180
November	1st to 10th	Day	60% 6% 10% 16% 7%	1851
	11th to 20th	Day	67% 5% 8% 13% 7%	1743
	21st to end	Day	72% 6% 7% 9% 5% 1	1680
December	1st to 10th	Day	76% 4 6% 11% 3	2680
	11th to 20th	Day	66% 4 7% 15% 7%	3066
	21st to end	Day	68% 5% 6% 13% 8%	4048
January	1st to 10th	Night	73% 4 8% 12% 3	8234
	11th to 20th	Night	75% 6% 6% 9% 4 1	8280
	21st to end	Night	65% 4 6% 13% 12%	9057
February	1st to 10th	Night	61% 6% 9% 16% 7% 1	2800
	11th to 20th	Night	63% 6% 8% 14% 8% 1	2592
	21st to end	Night	57% 6% 8% 17% 11% 1	2076
March	1st to 10th	Night	67% 5% 7% 8% 10% 2	5494
	11th to 20th	Night	58% 5% 11% 13% 10% 2	5322
	21st to end	Night	57% 5% 7% 19% 9% 3	4972
April	1st to 10th	Night	59% 6% 8% 14% 11% 2	2000
	11th to 20th	Night	49% 7% 10% 20% 12% 2	1975
	21st to end	Night	53% 5% 9% 20% 12% 2	1824
May	1st to 10th	Night	55% 9% 11% 16% 9% 2	3600
	11th to 20th	Night	50% 10% 13% 16% 9% 1	3576
	21st to end	Night	54% 7% 12% 16% 10% 1	3927
June	1st to 10th	Night	49% 8% 13% 19% 11% 1	1600
	11th to 20th	Night	47% 7% 12% 21% 10% 3	1600
	21st to end	Night	48% 8% 15% 18% 12%	1600
July	1st to 10th	Night	49% 7% 20% 19% 4	3560
	11th to 20th	Night	41% 6% 21% 28% 4	3552
	21st to end	Night	36% 6% 18% 31% 9%	3809
August	1st to 10th	Night	44% 7% 20% 22% 7%	2576
	11th to 20th	Night	46% 7% 19% 22% 5%	2812
	21st to end	Night	47% 6% 15% 22% 10% 1	3586
September	1st to 10th	Night	40% 7% 17% 24% 11%	2000
	11th to 20th	Night	39% 7% 15% 29% 8% 1	2070
	21st to end	Night	44% 6% 14% 26% 10%	2200
October	1st to 10th	Night	47% 4 15% 24% 9% 1	3850
	11th to 20th	Night	55% 5% 13% 19% 7%	3986
	21st to end	Night	56% 5% 15% 15% 7% 2	4610
November	1st to 10th	Night	58% 8% 11% 17% 5% 1	2667
	11th to 20th	Night	63% 7% 9% 13% 7% 1	2875
	21st to end	Night	70% 5% 9% 12% 4	2940
December	1st to 10th	Night	75% 4 10% 8% 3	4720
	11th to 20th	Night	70% 4 5% 13% 7% 1	5348
	21st to end	Night	69% 5% 4 11% 10% 1	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	22% 27% 35% 13% 3	220
	11th to 20th	Day	26% 19% 37% 12% 5%	220
	21st to end	Day	18% 26% 34% 17% 5%	242
February	1st to 10th	Day	26% 28% 34% 10% 1 1	292
	11th to 20th	Day	26% 26% 35% 11% 1	402
	21st to end	Day	29% 25% 31% 12% 2	446
March	1st to 10th	Day	25% 24% 35% 13% 3	540
	11th to 20th	Day	27% 26% 30% 13% 3 1	528
	21st to end	Day	29% 26% 26% 13% 4 2	550
April	1st to 10th	Day	31% 21% 30% 12% 5%	500
	11th to 20th	Day	34% 23% 21% 11% 9% 2	492
	21st to end	Day	31% 22% 31% 10% 5% 1	500
May	1st to 10th	Day	30% 21% 30% 13% 5% 1	503
	11th to 20th	Day	25% 20% 31% 17% 5% 2	527
	21st to end	Day	29% 18% 31% 16% 5% 2	573
June	1st to 10th	Day	27% 18% 34% 15% 4 1	530
	11th to 20th	Day	20% 19% 33% 17% 10% 1	530
	21st to end	Day	27% 15% 34% 18% 5% 1	530
July	1st to 10th	Day	17% 14% 38% 21% 7% 2	525
	11th to 20th	Day	17% 15% 37% 25% 5% 2	524
	21st to end	Day	15% 13% 37% 24% 10% 1	576
August	1st to 10th	Day	16% 12% 31% 28% 10% 2	526
	11th to 20th	Day	16% 9% 30% 27% 13% 5%	519
	21st to end	Day	18% 16% 30% 19% 12% 5%	583
September	1st to 10th	Day	20% 17% 29% 18% 10% 5%	530
	11th to 20th	Day	18% 12% 26% 24% 15% 6%	530
	21st to end	Day	25% 14% 27% 19% 10% 5%	530
October	1st to 10th	Day	23% 17% 29% 18% 10% 4	530
	11th to 20th	Day	28% 22% 26% 16% 6% 2	500
	21st to end	Day	31% 18% 30% 17% 4	462
November	1st to 10th	Day	33% 21% 27% 15% 3	425
	11th to 20th	Day	30% 23% 29% 13% 5%	283
	21st to end	Day	37% 27% 25% 7% 3 1	220
December	1st to 10th	Day	29% 18% 31% 15% 6%	220
	11th to 20th	Day	32% 26% 29% 11% 2	220
	21st to end	Day	30% 22% 30% 12% 4 1	242
January	1st to 10th	Night	23% 21% 38% 14% 4	840
	11th to 20th	Night	21% 22% 34% 17% 5%	840
	21st to end	Night	14% 18% 39% 23% 5%	924
February	1st to 10th	Night	15% 23% 38% 18% 5% 1	840
	11th to 20th	Night	20% 22% 37% 17% 3	823
	21st to end	Night	21% 18% 37% 20% 4	692
March	1st to 10th	Night	28% 18% 31% 19% 3	840
	11th to 20th	Night	25% 22% 30% 17% 4 1	829
	21st to end	Night	22% 17% 33% 23% 5%	880
April	1st to 10th	Night	30% 16% 28% 22% 4	800
	11th to 20th	Night	24% 18% 29% 20% 9%	791
	21st to end	Night	29% 17% 28% 20% 6%	624
May	1st to 10th	Night	27% 13% 29% 23% 9% 1	400
	11th to 20th	Night	26% 9% 31% 25% 8% 1	394
	21st to end	Night	21% 12% 39% 21% 8%	433
June	1st to 10th	Night	22% 9% 35% 27% 7%	400
	11th to 20th	Night	20% 9% 29% 31% 11% 1	400
	21st to end	Night	22% 8% 25% 32% 13% 1	400
July	1st to 10th	Night	14% 7% 34% 37% 8% 1	390
	11th to 20th	Night	15% 4 32% 35% 14% 1	388
	21st to end	Night	11% 7% 31% 38% 12% 1	438
August	1st to 10th	Night	12% 7% 20% 44% 15% 1	398
	11th to 20th	Night	16% 5% 25% 34% 19% 1	530
	21st to end	Night	21% 9% 26% 27% 14% 3	880
September	1st to 10th	Night	20% 9% 27% 33% 11% 1	800
	11th to 20th	Night	19% 8% 27% 27% 18% 2	800
	21st to end	Night	22% 11% 27% 24% 14% 2	800
October	1st to 10th	Night	22% 15% 29% 23% 11% 1	800
	11th to 20th	Night	29% 15% 29% 18% 8% 1	800
	21st to end	Night	30% 16% 27% 22% 5%	880
November	1st to 10th	Night	27% 20% 30% 17% 5% 1	820
	11th to 20th	Night	24% 18% 33% 16% 8% 1	840
	21st to end	Night	30% 23% 25% 17% 5% 1	840
December	1st to 10th	Night	28% 19% 31% 17% 5% 1	840
	11th to 20th	Night	28% 19% 32% 15% 6% 1	840
	21st to end	Night	30% 20% 30% 15% 4 1	924

Page generated at 2026-03-15 02:23:51. Version ac07

Copyright © 2026 Attilla Danko.