Parc du Mont Ste-Anne
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parc du Mont Ste-Anne clear sky chart from 2005-11-06 to 2024-11-05.

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	16% 9% 3 8% 5% 5% 5% 4 6% 7% 31%	101465
	Night	16% 11% 4 8% 5% 5% 5% 4 5% 6% 32%	97600
Transparency	Day	50% 6% 14% 20% 9% 1	104924
	Night	51% 5% 12% 20% 10% 1	102231
Seeing	Day	24% 17% 31% 19% 7% 1	15363
	Night	22% 14% 29% 27% 8% 1	23727

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% 16% 5% 9% 7% 5% 5% 5% 6% 7% 25%	2517
	11th to 20th	Day	10% 10% 5% 16% 6% 6% 5% 4 5% 4 27%	2520
	21st to end	Day	8% 7% 5% 9% 5% 5% 6% 5% 6% 7% 37%	2772
February	1st to 10th	Day	7% 13% 5% 12% 8% 6% 5% 5% 6% 6% 27%	1528
	11th to 20th	Day	11% 13% 5% 13% 8% 5% 5% 4 4 6% 27%	1810
	21st to end	Day	11% 13% 4 11% 8% 5% 5% 4 5% 7% 27%	1570
March	1st to 10th	Day	18% 12% 3 9% 7% 5% 4 3 5% 5% 29%	3116
	11th to 20th	Day	13% 19% 5% 10% 5% 5% 5% 4 4 4 26%	3342
	21st to end	Day	12% 15% 5% 8% 5% 4 4 3 3 4 35%	4028
April	1st to 10th	Day	19% 12% 4 10% 6% 4 4 3 5% 5% 28%	2280
	11th to 20th	Day	19% 8% 4 7% 4 5% 6% 3 5% 5% 35%	2364
	21st to end	Day	22% 9% 3 7% 5% 5% 4 3 5% 6% 31%	2470
May	1st to 10th	Day	19% 7% 3 7% 5% 5% 5% 3 5% 6% 36%	4192
	11th to 20th	Day	17% 8% 2 7% 6% 5% 5% 4 5% 8% 33%	4398
	21st to end	Day	17% 7% 2 8% 5% 6% 6% 5% 7% 7% 30%	4992
June	1st to 10th	Day	19% 7% 3 7% 6% 6% 6% 5% 6% 7% 27%	2850
	11th to 20th	Day	19% 8% 2 6% 5% 5% 5% 4 6% 7% 33%	2850
	21st to end	Day	22% 8% 4 8% 5% 5% 4 4 6% 7% 26%	2850
July	1st to 10th	Day	15% 8% 3 8% 6% 5% 6% 5% 7% 9% 29%	4611
	11th to 20th	Day	15% 5% 3 7% 5% 6% 6% 5% 9% 9% 30%	4440
	21st to end	Day	13% 6% 2 6% 4 4 6% 5% 7% 8% 37%	4814
August	1st to 10th	Day	13% 5% 2 8% 6% 6% 8% 5% 9% 9% 29%	4379
	11th to 20th	Day	18% 7% 3 7% 6% 6% 6% 5% 7% 9% 26%	4045
	21st to end	Day	17% 7% 2 6% 4 5% 5% 4 6% 7% 37%	4381
September	1st to 10th	Day	16% 7% 2 6% 5% 5% 4 4 6% 9% 35%	2280
	11th to 20th	Day	16% 6% 2 6% 3 4 4 3 5% 7% 44%	2100
	21st to end	Day	21% 8% 2 7% 4 3 4 3 5% 6% 37%	2090
October	1st to 10th	Day	18% 9% 2 8% 5% 5% 4 4 5% 6% 34%	2090
	11th to 20th	Day	21% 10% 3 9% 5% 7% 5% 3 5% 5% 27%	1733
	21st to end	Day	25% 11% 3 8% 5% 4 4 3 4 7% 26%	1881
November	1st to 10th	Day	16% 12% 4 8% 4 5% 5% 4 4 7% 31%	1708
	11th to 20th	Day	19% 12% 4 9% 7% 5% 5% 4 4 5% 26%	1694
	21st to end	Day	17% 17% 5% 8% 6% 3 4 4 5% 5% 25%	1340
December	1st to 10th	Day	19% 15% 6% 10% 6% 4 4 3 3 6% 24%	1330
	11th to 20th	Day	18% 13% 4 10% 6% 6% 4 3 5% 4 28%	1668
	21st to end	Day	17% 14% 4 10% 6% 4 4 3 5% 5% 29%	2432
January	1st to 10th	Night	10% 14% 6% 14% 7% 6% 6% 4 5% 5% 22%	4429
	11th to 20th	Night	8% 13% 5% 14% 8% 6% 6% 4 5% 5% 24%	4440
	21st to end	Night	6% 10% 5% 12% 6% 7% 6% 4 7% 7% 29%	4884
February	1st to 10th	Night	9% 12% 4 11% 7% 6% 5% 4 6% 7% 31%	2651
	11th to 20th	Night	9% 15% 6% 12% 5% 5% 4 4 5% 6% 28%	2252
	21st to end	Night	12% 13% 4 10% 8% 5% 5% 4 5% 7% 28%	1884
March	1st to 10th	Night	19% 13% 4 7% 5% 4 5% 3 4 6% 29%	3724
	11th to 20th	Night	12% 19% 6% 10% 6% 5% 5% 3 4 5% 25%	3617
	21st to end	Night	14% 14% 5% 10% 5% 4 4 3 4 4 32%	3603
April	1st to 10th	Night	19% 14% 4 8% 4 4 4 3 5% 4 30%	1900
	11th to 20th	Night	18% 9% 2 5% 4 5% 5% 4 6% 7% 35%	1763
	21st to end	Night	23% 8% 3 7% 5% 4 4 3 5% 5% 35%	1710
May	1st to 10th	Night	20% 8% 2 7% 3 4 4 4 5% 6% 37%	2778
	11th to 20th	Night	21% 8% 3 6% 5% 4 4 4 5% 6% 33%	2495
	21st to end	Night	18% 5% 2 5% 4 5% 6% 5% 7% 8% 37%	2586
June	1st to 10th	Night	17% 9% 3 8% 6% 5% 6% 4 7% 8% 28%	1330
	11th to 20th	Night	18% 6% 2 6% 4 4 4 3 7% 6% 40%	1330
	21st to end	Night	25% 9% 3 6% 5% 4 4 3 4 7% 31%	1330
July	1st to 10th	Night	12% 6% 3 8% 6% 5% 6% 6% 7% 9% 33%	2350
	11th to 20th	Night	17% 5% 2 6% 4 5% 5% 4 7% 8% 38%	2520
	21st to end	Night	13% 4 2 5% 4 3 4 4 6% 8% 45%	2739
August	1st to 10th	Night	17% 7% 3 7% 4 5% 5% 3 5% 7% 39%	2506
	11th to 20th	Night	18% 6% 3 7% 5% 5% 5% 4 6% 7% 34%	2782
	21st to end	Night	14% 6% 3 7% 5% 5% 5% 4 5% 7% 39%	3273
September	1st to 10th	Night	15% 7% 2 6% 4 4 4 3 5% 7% 42%	1900
	11th to 20th	Night	18% 6% 2 6% 4 3 4 3 5% 6% 44%	2080
	21st to end	Night	18% 7% 2 6% 4 3 4 3 4 5% 42%	2090
October	1st to 10th	Night	18% 8% 2 7% 4 4 5% 3 4 6% 38%	2090
	11th to 20th	Night	23% 8% 2 7% 6% 4 5% 3 5% 5% 33%	2444
	21st to end	Night	23% 10% 2 7% 4 4 4 4 5% 7% 30%	2717
November	1st to 10th	Night	16% 10% 4 7% 4 4 5% 4 6% 7% 33%	2470
	11th to 20th	Night	17% 11% 4 6% 4 4 4 4 6% 6% 33%	2484
	21st to end	Night	17% 15% 4 8% 5% 5% 4 4 6% 5% 27%	2836
December	1st to 10th	Night	17% 15% 5% 10% 7% 5% 5% 4 4 6% 22%	2850
	11th to 20th	Night	18% 12% 4 10% 6% 4 4 3 5% 5% 28%	3531
	21st to end	Night	18% 16% 5% 9% 5% 4 3 2 3 4 30%	5232

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	58% 3 13% 20% 6% 1	2518
	11th to 20th	Day	58% 5% 8% 17% 10% 1	2520
	21st to end	Day	44% 4 15% 22% 14% 1	2772
February	1st to 10th	Day	56% 5% 9% 18% 10% 3	1528
	11th to 20th	Day	58% 4 8% 15% 12% 2	1819
	21st to end	Day	55% 5% 7% 19% 10% 3	1570
March	1st to 10th	Day	58% 3 11% 15% 9% 3	3119
	11th to 20th	Day	60% 5% 9% 17% 8% 2	3342
	21st to end	Day	53% 3 7% 18% 13% 6%	4028
April	1st to 10th	Day	57% 5% 10% 13% 11% 4	2280
	11th to 20th	Day	48% 6% 9% 23% 11% 3	2364
	21st to end	Day	53% 5% 10% 17% 12% 3	2470
May	1st to 10th	Day	48% 4 14% 18% 15% 1	4206
	11th to 20th	Day	49% 4 18% 22% 6% 1	4402
	21st to end	Day	51% 5% 10% 22% 13%	4992
June	1st to 10th	Day	52% 7% 12% 20% 7% 1	2850
	11th to 20th	Day	48% 6% 15% 20% 9% 1	2850
	21st to end	Day	56% 7% 13% 17% 8%	2850
July	1st to 10th	Day	48% 7% 18% 21% 6%	4540
	11th to 20th	Day	44% 10% 20% 21% 5%	4365
	21st to end	Day	41% 8% 19% 24% 9%	4661
August	1st to 10th	Day	44% 9% 21% 18% 8%	4365
	11th to 20th	Day	50% 8% 21% 16% 4	4084
	21st to end	Day	44% 8% 17% 19% 12% 1	4381
September	1st to 10th	Day	44% 6% 16% 25% 10%	2280
	11th to 20th	Day	38% 6% 16% 29% 10% 1	2100
	21st to end	Day	47% 4 13% 25% 10%	2090
October	1st to 10th	Day	50% 7% 11% 24% 7%	3480
	11th to 20th	Day	49% 6% 16% 25% 4	2845
	21st to end	Day	48% 5% 20% 15% 11%	3081
November	1st to 10th	Day	52% 7% 11% 21% 8% 1	1708
	11th to 20th	Day	57% 6% 8% 19% 8% 1	1694
	21st to end	Day	59% 6% 12% 14% 7% 1	1340
December	1st to 10th	Day	62% 4 10% 15% 7%	1330
	11th to 20th	Day	59% 4 6% 19% 10% 1	1668
	21st to end	Day	58% 4 11% 17% 8% 3	2432
January	1st to 10th	Night	63% 4 9% 15% 8% 1	4429
	11th to 20th	Night	61% 4 9% 18% 7% 1	4440
	21st to end	Night	53% 3 11% 19% 12% 2	4884
February	1st to 10th	Night	50% 6% 10% 21% 12% 1	2651
	11th to 20th	Night	56% 4 10% 16% 13% 1	2254
	21st to end	Night	54% 4 8% 18% 14% 2	1884
March	1st to 10th	Night	57% 3 12% 16% 10% 2	3734
	11th to 20th	Night	62% 3 10% 16% 7% 2	3618
	21st to end	Night	56% 3 6% 22% 10% 3	3603
April	1st to 10th	Night	56% 3 7% 16% 13% 4	1900
	11th to 20th	Night	46% 5% 9% 25% 13% 2	1763
	21st to end	Night	53% 4 8% 19% 14% 3	1710
May	1st to 10th	Night	48% 4 11% 24% 12% 2	2784
	11th to 20th	Night	50% 4 14% 20% 11% 1	2496
	21st to end	Night	43% 5% 14% 21% 16% 1	2587
June	1st to 10th	Night	52% 5% 12% 22% 7% 1	1330
	11th to 20th	Night	43% 5% 13% 25% 11% 3	1330
	21st to end	Night	54% 6% 13% 17% 10%	1330
July	1st to 10th	Night	44% 6% 21% 23% 6%	2311
	11th to 20th	Night	42% 6% 24% 24% 4	2472
	21st to end	Night	35% 8% 24% 23% 10%	2651
August	1st to 10th	Night	45% 6% 17% 26% 6%	2496
	11th to 20th	Night	47% 8% 22% 16% 7%	2809
	21st to end	Night	42% 7% 16% 24% 11%	3273
September	1st to 10th	Night	41% 6% 15% 25% 12% 1	1900
	11th to 20th	Night	40% 5% 18% 28% 8%	2080
	21st to end	Night	44% 5% 12% 27% 12%	2090
October	1st to 10th	Night	48% 6% 10% 27% 9%	3480
	11th to 20th	Night	48% 5% 13% 28% 5%	4071
	21st to end	Night	45% 4 19% 18% 12% 1	4467
November	1st to 10th	Night	49% 6% 12% 24% 8% 1	2470
	11th to 20th	Night	50% 6% 12% 20% 11% 1	2484
	21st to end	Night	57% 6% 10% 18% 8% 1	2836
December	1st to 10th	Night	63% 5% 10% 15% 6% 1	2850
	11th to 20th	Night	58% 4 8% 17% 12% 1	3532
	21st to end	Night	60% 2 9% 16% 10% 2	5232

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% 23% 35% 13% 7% 1	180
	11th to 20th	Day	23% 28% 32% 12% 4	180
	21st to end	Day	15% 26% 37% 16% 5% 1	198
February	1st to 10th	Day	26% 31% 33% 7% 3	188
	11th to 20th	Day	20% 24% 37% 15% 4	438
	21st to end	Day	24% 23% 31% 18% 4	382
March	1st to 10th	Day	24% 23% 32% 17% 3 1	460
	11th to 20th	Day	26% 19% 32% 16% 6% 1	460
	21st to end	Day	24% 20% 31% 17% 7% 1	506
April	1st to 10th	Day	27% 22% 29% 15% 5% 1	460
	11th to 20th	Day	29% 19% 31% 16% 4 2	452
	21st to end	Day	28% 19% 35% 13% 2 2	460
May	1st to 10th	Day	28% 17% 32% 17% 6% 1	463
	11th to 20th	Day	22% 14% 36% 20% 7% 2	487
	21st to end	Day	24% 20% 31% 18% 6%	619
June	1st to 10th	Day	24% 14% 32% 22% 8% 1	680
	11th to 20th	Day	23% 16% 28% 24% 9% 1	680
	21st to end	Day	25% 14% 26% 26% 8% 1	680
July	1st to 10th	Day	18% 15% 33% 24% 9% 1	590
	11th to 20th	Day	19% 12% 38% 23% 7% 1	484
	21st to end	Day	17% 11% 36% 26% 8% 1	532
August	1st to 10th	Day	17% 14% 34% 24% 9% 2	486
	11th to 20th	Day	18% 10% 30% 26% 13% 3	479
	21st to end	Day	19% 18% 27% 20% 11% 5%	539
September	1st to 10th	Day	20% 14% 29% 25% 8% 4	490
	11th to 20th	Day	20% 13% 33% 21% 10% 4	490
	21st to end	Day	23% 16% 27% 21% 9% 4	490
October	1st to 10th	Day	23% 16% 29% 22% 9% 2	490
	11th to 20th	Day	27% 19% 28% 17% 9% 1	395
	21st to end	Day	37% 17% 24% 17% 5% 1	429
November	1st to 10th	Day	28% 19% 31% 17% 5% 1	378
	11th to 20th	Day	28% 19% 24% 20% 8% 1	370
	21st to end	Day	29% 23% 33% 13% 2	190
December	1st to 10th	Day	27% 17% 27% 22% 7%	180
	11th to 20th	Day	31% 23% 27% 13% 4 1	180
	21st to end	Day	31% 21% 31% 13% 5%	198
January	1st to 10th	Night	21% 17% 31% 26% 4	760
	11th to 20th	Night	21% 18% 32% 23% 6%	760
	21st to end	Night	14% 16% 33% 30% 6% 1	836
February	1st to 10th	Night	14% 20% 33% 26% 6%	760
	11th to 20th	Night	19% 19% 36% 21% 5% 1	743
	21st to end	Night	21% 15% 33% 25% 5%	628
March	1st to 10th	Night	19% 17% 35% 24% 4	760
	11th to 20th	Night	20% 18% 34% 21% 7% 1	760
	21st to end	Night	20% 17% 33% 22% 7% 1	836
April	1st to 10th	Night	29% 15% 28% 22% 6%	760
	11th to 20th	Night	25% 12% 33% 24% 7%	639
	21st to end	Night	29% 11% 30% 23% 6% 1	570
May	1st to 10th	Night	25% 11% 30% 28% 6% 1	540
	11th to 20th	Night	21% 11% 27% 32% 9%	374
	21st to end	Night	25% 9% 33% 27% 7%	411
June	1st to 10th	Night	22% 9% 27% 30% 11% 1	380
	11th to 20th	Night	20% 6% 23% 37% 12% 1	380
	21st to end	Night	25% 7% 19% 38% 10% 1	380
July	1st to 10th	Night	19% 6% 31% 32% 11% 1	370
	11th to 20th	Night	19% 5% 24% 39% 12% 1	368
	21st to end	Night	17% 4 20% 44% 13% 1	416
August	1st to 10th	Night	17% 3 22% 40% 17% 1	378
	11th to 20th	Night	18% 7% 23% 34% 17% 1	562
	21st to end	Night	17% 9% 24% 34% 15% 2	711
September	1st to 10th	Night	18% 6% 27% 36% 12% 1	760
	11th to 20th	Night	20% 7% 28% 28% 15% 2	760
	21st to end	Night	22% 11% 23% 31% 13% 1	760
October	1st to 10th	Night	22% 12% 25% 29% 11% 1	760
	11th to 20th	Night	26% 12% 26% 26% 9% 1	760
	21st to end	Night	30% 14% 28% 20% 7%	836
November	1st to 10th	Night	24% 17% 29% 22% 7% 1	760
	11th to 20th	Night	23% 19% 24% 24% 9% 1	766
	21st to end	Night	26% 18% 28% 22% 5% 1	850
December	1st to 10th	Night	27% 15% 26% 24% 7% 1	850
	11th to 20th	Night	23% 21% 26% 24% 5% 1	850
	21st to end	Night	27% 19% 28% 19% 7% 1	933

Page generated at 2024-11-03 02:11:09. Version ac07

Copyright © 2024 Attilla Danko.