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 2024-12-06.

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% 12% 4 10% 6% 5% 5% 4 5% 6% 28%	101864
	Night	15% 13% 5% 10% 6% 5% 5% 3 5% 6% 27%	97861
Transparency	Day	55% 7% 12% 17% 8% 1	105314
	Night	56% 7% 12% 16% 8% 1	102500
Seeing	Day	25% 19% 31% 17% 7% 2	14539
	Night	23% 16% 31% 22% 8% 1	23518

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% 18% 7% 16% 9% 7% 5% 3 4 3 15%	2517
	11th to 20th	Day	9% 14% 7% 20% 12% 5% 3 2 3 3 20%	2520
	21st to end	Day	10% 12% 8% 17% 7% 6% 6% 5% 6% 6% 18%	2772
February	1st to 10th	Day	8% 18% 6% 14% 10% 7% 5% 3 5% 6% 20%	1643
	11th to 20th	Day	10% 17% 6% 13% 7% 7% 5% 4 5% 4 23%	1727
	21st to end	Day	13% 18% 6% 12% 7% 6% 5% 3 4 3 23%	1570
March	1st to 10th	Day	13% 19% 5% 12% 7% 5% 4 3 4 3 24%	3116
	11th to 20th	Day	11% 20% 7% 13% 6% 4 4 3 4 5% 22%	3303
	21st to end	Day	9% 14% 4 11% 5% 4 4 3 5% 6% 34%	4156
April	1st to 10th	Day	18% 19% 5% 10% 5% 4 3 3 3 5% 25%	2280
	11th to 20th	Day	21% 12% 4 7% 4 4 4 3 4 4 33%	2254
	21st to end	Day	20% 14% 4 8% 5% 4 3 3 4 5% 29%	2461
May	1st to 10th	Day	20% 12% 3 8% 5% 4 4 4 5% 6% 28%	4426
	11th to 20th	Day	17% 8% 3 8% 5% 5% 6% 4 6% 8% 30%	4398
	21st to end	Day	18% 9% 3 8% 5% 5% 5% 4 5% 6% 32%	4837
June	1st to 10th	Day	24% 9% 3 8% 5% 4 5% 3 6% 6% 27%	2660
	11th to 20th	Day	18% 7% 3 7% 6% 5% 4 4 6% 9% 32%	2660
	21st to end	Day	23% 10% 3 8% 6% 5% 5% 4 6% 7% 24%	2660
July	1st to 10th	Day	14% 9% 3 9% 6% 5% 6% 5% 6% 8% 28%	4440
	11th to 20th	Day	13% 7% 3 7% 6% 6% 6% 5% 7% 9% 31%	4440
	21st to end	Day	12% 7% 3 7% 4 5% 6% 4 5% 7% 40%	4814
August	1st to 10th	Day	16% 7% 3 8% 6% 6% 6% 5% 7% 8% 28%	4423
	11th to 20th	Day	17% 7% 4 8% 5% 5% 5% 4 6% 7% 32%	4094
	21st to end	Day	15% 7% 3 8% 5% 5% 5% 4 6% 8% 34%	4180
September	1st to 10th	Day	16% 7% 3 6% 4 5% 4 4 6% 8% 38%	2280
	11th to 20th	Day	16% 8% 3 6% 4 4 4 3 5% 6% 40%	2214
	21st to end	Day	22% 9% 2 6% 4 4 4 3 4 7% 35%	2090
October	1st to 10th	Day	21% 12% 3 8% 5% 5% 4 3 5% 6% 30%	1938
	11th to 20th	Day	21% 16% 4 10% 6% 4 5% 3 4 4 23%	1851
	21st to end	Day	23% 16% 5% 10% 5% 5% 4 2 4 4 22%	1881
November	1st to 10th	Day	15% 17% 5% 9% 5% 5% 4 3 4 4 29%	1761
	11th to 20th	Day	15% 19% 5% 12% 6% 5% 4 3 4 5% 21%	1660
	21st to end	Day	16% 21% 7% 14% 7% 4 3 3 3 4 18%	1600
December	1st to 10th	Day	19% 21% 6% 13% 6% 5% 4 3 4 4 15%	1560
	11th to 20th	Day	17% 18% 5% 14% 6% 4 4 3 4 6% 18%	1906
	21st to end	Day	18% 18% 7% 13% 8% 5% 5% 3 3 5% 16%	2772
January	1st to 10th	Night	13% 18% 8% 16% 7% 5% 4 4 4 4 17%	4429
	11th to 20th	Night	9% 13% 5% 16% 12% 9% 6% 4 4 5% 16%	4440
	21st to end	Night	8% 14% 8% 18% 8% 8% 6% 3 5% 5% 16%	4884
February	1st to 10th	Night	9% 15% 6% 12% 10% 7% 5% 6% 5% 5% 21%	2534
	11th to 20th	Night	9% 16% 6% 13% 8% 9% 6% 4 4 5% 21%	2338
	21st to end	Night	12% 15% 5% 10% 7% 5% 5% 3 5% 5% 26%	1884
March	1st to 10th	Night	18% 17% 5% 9% 7% 4 5% 3 4 4 25%	3724
	11th to 20th	Night	14% 21% 6% 13% 5% 4 3 2 4 4 24%	3653
	21st to end	Night	12% 11% 5% 11% 6% 6% 5% 3 4 5% 32%	3476
April	1st to 10th	Night	20% 14% 4 10% 5% 3 4 3 4 5% 26%	1900
	11th to 20th	Night	17% 11% 4 7% 4 4 4 3 4 7% 35%	1875
	21st to end	Night	20% 12% 5% 8% 4 3 4 3 4 5% 34%	1733
May	1st to 10th	Night	20% 10% 3 7% 6% 5% 4 4 5% 6% 29%	2514
	11th to 20th	Night	17% 9% 3 7% 4 4 4 4 5% 6% 35%	2495
	21st to end	Night	19% 8% 3 8% 5% 5% 4 4 6% 7% 31%	2738
June	1st to 10th	Night	20% 9% 2 7% 5% 5% 4 4 6% 8% 31%	1520
	11th to 20th	Night	16% 8% 3 7% 5% 5% 5% 3 5% 7% 37%	1520
	21st to end	Night	19% 8% 3 6% 5% 4 4 4 5% 7% 35%	1520
July	1st to 10th	Night	12% 10% 3 9% 5% 6% 5% 4 6% 8% 31%	2520
	11th to 20th	Night	13% 6% 2 6% 6% 5% 5% 3 6% 9% 38%	2520
	21st to end	Night	9% 6% 2 6% 4 4 5% 4 6% 8% 46%	2739
August	1st to 10th	Night	11% 8% 3 8% 5% 5% 5% 4 6% 7% 37%	2506
	11th to 20th	Night	16% 8% 4 7% 5% 5% 4 3 6% 6% 35%	2701
	21st to end	Night	17% 9% 3 7% 5% 4 4 4 5% 7% 36%	3476
September	1st to 10th	Night	15% 8% 2 6% 4 4 4 3 4 7% 42%	1900
	11th to 20th	Night	17% 6% 2 5% 4 3 4 3 5% 6% 44%	1966
	21st to end	Night	16% 10% 3 6% 4 4 4 3 4 6% 41%	2090
October	1st to 10th	Night	16% 11% 3 7% 4 4 5% 3 4 6% 38%	2238
	11th to 20th	Night	20% 16% 4 8% 4 4 4 3 4 6% 27%	2327
	21st to end	Night	23% 15% 4 8% 6% 4 4 3 5% 6% 23%	2717
November	1st to 10th	Night	14% 16% 5% 9% 5% 5% 5% 4 5% 6% 26%	2537
	11th to 20th	Night	14% 14% 6% 13% 7% 6% 4 3 5% 6% 23%	2738
	21st to end	Night	17% 20% 7% 12% 7% 4 4 3 4 4 18%	2800
December	1st to 10th	Night	16% 20% 8% 15% 8% 4 4 3 5% 4 14%	2737
	11th to 20th	Night	17% 18% 6% 13% 7% 5% 4 3 4 5% 18%	3288
	21st to end	Night	19% 21% 6% 14% 7% 4 4 3 3 4 15%	4884

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	70% 8% 9% 10% 4	2518
	11th to 20th	Day	69% 4 6% 14% 6% 1	2520
	21st to end	Day	65% 8% 7% 13% 6% 1	2772
February	1st to 10th	Day	66% 4 7% 15% 7% 2	1643
	11th to 20th	Day	63% 5% 9% 12% 10% 1	1736
	21st to end	Day	65% 4 6% 13% 8% 3	1570
March	1st to 10th	Day	63% 7% 6% 13% 10% 2	3119
	11th to 20th	Day	62% 7% 9% 10% 9% 3	3303
	21st to end	Day	48% 7% 9% 18% 15% 3	4156
April	1st to 10th	Day	61% 5% 9% 14% 9% 2	2280
	11th to 20th	Day	54% 5% 8% 19% 11% 2	2254
	21st to end	Day	57% 6% 8% 14% 12% 3	2461
May	1st to 10th	Day	53% 8% 11% 17% 10% 1	4440
	11th to 20th	Day	45% 13% 17% 16% 8% 1	4402
	21st to end	Day	49% 10% 10% 16% 14% 1	4837
June	1st to 10th	Day	55% 8% 10% 16% 9% 1	2660
	11th to 20th	Day	47% 9% 13% 18% 10% 2	2660
	21st to end	Day	58% 8% 11% 15% 8%	2660
July	1st to 10th	Day	51% 6% 14% 23% 6%	4370
	11th to 20th	Day	47% 8% 18% 22% 5%	4365
	21st to end	Day	42% 7% 17% 24% 10%	4661
August	1st to 10th	Day	51% 8% 15% 20% 6%	4409
	11th to 20th	Day	48% 7% 18% 23% 4	4136
	21st to end	Day	47% 7% 12% 21% 12% 1	4180
September	1st to 10th	Day	43% 8% 15% 24% 10% 1	2280
	11th to 20th	Day	43% 7% 15% 25% 9% 1	2214
	21st to end	Day	48% 7% 12% 23% 9%	2090
October	1st to 10th	Day	54% 5% 11% 24% 5%	3224
	11th to 20th	Day	58% 6% 12% 20% 4	3054
	21st to end	Day	58% 4 18% 14% 5% 1	3081
November	1st to 10th	Day	58% 7% 11% 17% 8% 1	1761
	11th to 20th	Day	66% 5% 8% 13% 7%	1660
	21st to end	Day	71% 6% 8% 10% 5% 1	1600
December	1st to 10th	Day	71% 6% 8% 10% 5%	1560
	11th to 20th	Day	66% 5% 10% 12% 7%	1906
	21st to end	Day	69% 6% 7% 11% 7%	2772
January	1st to 10th	Night	69% 6% 10% 11% 4	4429
	11th to 20th	Night	65% 9% 9% 11% 4 1	4440
	21st to end	Night	68% 6% 8% 10% 7% 1	4884
February	1st to 10th	Night	61% 6% 9% 15% 7% 1	2534
	11th to 20th	Night	62% 6% 9% 13% 8% 1	2340
	21st to end	Night	57% 6% 8% 16% 11% 2	1884
March	1st to 10th	Night	61% 7% 10% 10% 10% 3	3734
	11th to 20th	Night	63% 6% 6% 13% 11% 1	3654
	21st to end	Night	52% 7% 9% 18% 11% 4	3476
April	1st to 10th	Night	58% 6% 8% 14% 11% 2	1900
	11th to 20th	Night	49% 7% 10% 20% 12% 2	1875
	21st to end	Night	52% 5% 9% 20% 12% 2	1733
May	1st to 10th	Night	50% 11% 14% 15% 7% 2	2520
	11th to 20th	Night	44% 12% 16% 16% 10% 2	2496
	21st to end	Night	48% 9% 12% 18% 11% 1	2739
June	1st to 10th	Night	49% 8% 13% 19% 10% 1	1520
	11th to 20th	Night	46% 8% 12% 21% 10% 3	1520
	21st to end	Night	48% 8% 15% 18% 11%	1520
July	1st to 10th	Night	49% 7% 18% 19% 6%	2480
	11th to 20th	Night	42% 7% 21% 25% 4 1	2472
	21st to end	Night	35% 8% 20% 28% 9%	2651
August	1st to 10th	Night	45% 7% 19% 21% 7%	2496
	11th to 20th	Night	47% 7% 20% 21% 5%	2725
	21st to end	Night	47% 6% 15% 21% 10% 1	3476
September	1st to 10th	Night	40% 7% 17% 23% 12%	1900
	11th to 20th	Night	40% 7% 16% 29% 8% 1	1966
	21st to end	Night	44% 7% 13% 26% 10%	2090
October	1st to 10th	Night	48% 4 15% 23% 9%	3732
	11th to 20th	Night	56% 5% 13% 19% 7%	3863
	21st to end	Night	56% 5% 15% 15% 8% 2	4467
November	1st to 10th	Night	57% 8% 11% 17% 5% 1	2537
	11th to 20th	Night	61% 8% 9% 13% 7% 2	2738
	21st to end	Night	69% 6% 10% 12% 4	2800
December	1st to 10th	Night	73% 6% 9% 9% 4	2737
	11th to 20th	Night	68% 6% 7% 11% 8% 1	3288
	21st to end	Night	71% 6% 6% 12% 5%	4884

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	21% 29% 34% 14% 2	180
	11th to 20th	Day	27% 18% 37% 13% 5% 1	180
	21st to end	Day	19% 25% 35% 15% 6%	198
February	1st to 10th	Day	29% 32% 32% 6% 1	238
	11th to 20th	Day	26% 26% 37% 10%	334
	21st to end	Day	31% 27% 28% 12% 2	382
March	1st to 10th	Day	26% 21% 36% 14% 3	460
	11th to 20th	Day	25% 26% 31% 14% 3 1	460
	21st to end	Day	29% 26% 25% 14% 5% 2	506
April	1st to 10th	Day	29% 21% 31% 12% 5%	460
	11th to 20th	Day	33% 24% 22% 11% 9% 1	452
	21st to end	Day	31% 22% 31% 11% 5% 1	460
May	1st to 10th	Day	30% 21% 29% 14% 5% 1	463
	11th to 20th	Day	24% 21% 31% 18% 5% 2	487
	21st to end	Day	27% 20% 32% 16% 4 1	529
June	1st to 10th	Day	27% 18% 34% 16% 5% 1	490
	11th to 20th	Day	20% 20% 31% 17% 11% 1	490
	21st to end	Day	27% 14% 32% 19% 5% 1	490
July	1st to 10th	Day	16% 13% 39% 22% 7% 2	485
	11th to 20th	Day	17% 15% 36% 26% 5% 2	484
	21st to end	Day	15% 11% 36% 25% 10% 2	532
August	1st to 10th	Day	18% 13% 30% 27% 10% 2	486
	11th to 20th	Day	17% 9% 30% 27% 12% 5%	479
	21st to end	Day	17% 17% 30% 19% 12% 5%	539
September	1st to 10th	Day	21% 17% 29% 19% 10% 4	490
	11th to 20th	Day	19% 13% 26% 24% 14% 5%	490
	21st to end	Day	24% 14% 27% 19% 11% 5%	490
October	1st to 10th	Day	24% 18% 27% 17% 10% 3	490
	11th to 20th	Day	29% 23% 26% 15% 5% 2	463
	21st to end	Day	32% 19% 29% 16% 4	429
November	1st to 10th	Day	32% 20% 27% 16% 4 1	395
	11th to 20th	Day	30% 25% 30% 11% 5%	260
	21st to end	Day	36% 27% 27% 8% 3 1	200
December	1st to 10th	Day	31% 18% 29% 14% 7% 1	190
	11th to 20th	Day	33% 27% 27% 11% 2 1	180
	21st to end	Day	33% 25% 27% 10% 4 1	198
January	1st to 10th	Night	23% 21% 38% 13% 4	760
	11th to 20th	Night	21% 22% 35% 17% 5%	760
	21st to end	Night	15% 18% 40% 23% 5%	836
February	1st to 10th	Night	17% 22% 39% 18% 4 1	760
	11th to 20th	Night	20% 22% 37% 17% 3 1	743
	21st to end	Night	22% 20% 36% 19% 3	628
March	1st to 10th	Night	27% 18% 31% 20% 4	760
	11th to 20th	Night	25% 22% 29% 18% 5% 1	760
	21st to end	Night	22% 17% 33% 22% 5%	836
April	1st to 10th	Night	30% 16% 27% 23% 4	760
	11th to 20th	Night	24% 18% 30% 19% 9%	751
	21st to end	Night	29% 17% 29% 20% 6%	593
May	1st to 10th	Night	25% 14% 29% 22% 9% 1	380
	11th to 20th	Night	25% 9% 32% 26% 7% 1	374
	21st to end	Night	20% 13% 39% 21% 7%	411
June	1st to 10th	Night	22% 9% 35% 27% 7%	380
	11th to 20th	Night	20% 9% 29% 30% 11% 1	380
	21st to end	Night	22% 7% 25% 33% 12% 1	380
July	1st to 10th	Night	14% 7% 34% 37% 8% 1	370
	11th to 20th	Night	15% 4 32% 34% 15% 1	368
	21st to end	Night	12% 6% 30% 38% 13% 1	416
August	1st to 10th	Night	13% 7% 20% 44% 15%	378
	11th to 20th	Night	16% 5% 25% 33% 20% 1	503
	21st to end	Night	20% 9% 27% 26% 14% 3	836
September	1st to 10th	Night	20% 9% 27% 32% 11% 1	760
	11th to 20th	Night	20% 8% 28% 26% 17% 1	760
	21st to end	Night	23% 11% 27% 24% 14% 2	760
October	1st to 10th	Night	23% 15% 29% 22% 11% 1	760
	11th to 20th	Night	30% 15% 28% 18% 8% 1	760
	21st to end	Night	30% 16% 28% 21% 5%	836
November	1st to 10th	Night	26% 20% 30% 18% 6% 1	780
	11th to 20th	Night	24% 19% 32% 17% 7% 1	800
	21st to end	Night	30% 22% 26% 17% 5% 1	800
December	1st to 10th	Night	28% 19% 31% 16% 5% 1	783
	11th to 20th	Night	28% 19% 32% 14% 6% 1	760
	21st to end	Night	31% 21% 30% 14% 3	836

Page generated at 2024-12-03 06:45:10. Version ac07

Copyright © 2024 Attilla Danko.