Parc Canadian de la Mauricie
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parc Canadian de la Mauricie clear sky chart from 2005-11-06 to 2025-09-04.

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% 11% 4 9% 5% 5% 5% 4 5% 7% 29%	126115
	Night	16% 11% 4 9% 6% 5% 5% 4 5% 6% 29%	122596
Transparency	Day	54% 5% 12% 19% 10% 1	129548
	Night	54% 4 12% 19% 10% 1	127238
Seeing	Day	24% 17% 31% 18% 7% 2	15541
	Night	24% 13% 31% 25% 8% 1	24451

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% 21% 6% 15% 6% 5% 6% 4 4 4 17%	3597
	11th to 20th	Day	9% 15% 7% 17% 10% 6% 4 2 4 4 23%	3570
	21st to end	Day	8% 11% 7% 16% 6% 5% 4 4 4 7% 29%	3960
February	1st to 10th	Day	10% 19% 5% 12% 9% 6% 4 2 4 6% 23%	1677
	11th to 20th	Day	11% 19% 4 11% 7% 4 5% 3 5% 5% 26%	1863
	21st to end	Day	14% 18% 5% 11% 6% 5% 5% 3 3 5% 26%	1650
March	1st to 10th	Day	18% 19% 4 13% 6% 4 3 2 3 4 23%	4476
	11th to 20th	Day	11% 15% 5% 10% 6% 5% 4 3 5% 6% 30%	4679
	21st to end	Day	15% 16% 4 8% 5% 4 4 3 4 5% 33%	5970
April	1st to 10th	Day	20% 14% 4 8% 5% 4 4 3 4 4 29%	2400
	11th to 20th	Day	21% 10% 2 7% 5% 4 4 3 4 5% 35%	2395
	21st to end	Day	21% 11% 3 7% 5% 5% 4 4 5% 6% 29%	2600
May	1st to 10th	Day	25% 10% 3 8% 4 4 4 3 5% 6% 26%	6269
	11th to 20th	Day	22% 8% 3 6% 5% 4 5% 3 5% 8% 31%	6318
	21st to end	Day	21% 10% 3 8% 5% 5% 6% 4 5% 6% 28%	6949
June	1st to 10th	Day	21% 9% 3 8% 6% 5% 6% 4 6% 6% 27%	2800
	11th to 20th	Day	17% 8% 3 7% 6% 5% 5% 4 6% 7% 33%	2800
	21st to end	Day	22% 8% 3 9% 6% 5% 5% 5% 5% 7% 25%	2800
July	1st to 10th	Day	17% 7% 3 8% 6% 5% 5% 5% 7% 8% 28%	6360
	11th to 20th	Day	13% 6% 3 7% 5% 6% 6% 5% 7% 9% 33%	6360
	21st to end	Day	10% 5% 2 7% 5% 5% 5% 5% 8% 9% 39%	6926
August	1st to 10th	Day	14% 6% 3 9% 5% 6% 6% 5% 7% 9% 30%	4563
	11th to 20th	Day	18% 7% 3 6% 5% 5% 5% 4 7% 8% 30%	4257
	21st to end	Day	17% 7% 3 7% 5% 5% 4 4 6% 7% 34%	4312
September	1st to 10th	Day	15% 6% 2 6% 5% 5% 5% 4 6% 8% 39%	2316
	11th to 20th	Day	15% 6% 2 6% 4 4 4 3 5% 7% 42%	2176
	21st to end	Day	21% 8% 3 7% 4 3 4 3 4 7% 38%	2090
October	1st to 10th	Day	23% 8% 3 7% 4 4 3 4 5% 6% 33%	1991
	11th to 20th	Day	22% 11% 4 8% 6% 5% 5% 4 4 7% 23%	1810
	21st to end	Day	26% 12% 2 8% 4 3 5% 3 4 6% 26%	1881
November	1st to 10th	Day	17% 15% 3 9% 5% 5% 4 3 4 5% 30%	1761
	11th to 20th	Day	18% 15% 5% 9% 5% 4 4 4 4 6% 26%	1710
	21st to end	Day	20% 18% 5% 9% 5% 4 5% 3 4 6% 22%	1600
December	1st to 10th	Day	19% 18% 6% 12% 7% 5% 3 3 4 5% 18%	2427
	11th to 20th	Day	18% 13% 5% 12% 5% 6% 4 3 5% 5% 25%	2842
	21st to end	Day	17% 16% 4 11% 6% 4 4 3 4 5% 24%	3960
January	1st to 10th	Night	12% 20% 8% 15% 7% 6% 5% 3 4 5% 16%	6349
	11th to 20th	Night	9% 16% 7% 16% 8% 5% 5% 4 5% 5% 20%	6315
	21st to end	Night	8% 11% 5% 13% 8% 7% 6% 4 5% 6% 25%	6996
February	1st to 10th	Night	11% 14% 6% 9% 7% 6% 5% 3 5% 6% 29%	2720
	11th to 20th	Night	10% 15% 5% 12% 6% 6% 5% 4 5% 5% 26%	2421
	21st to end	Night	14% 14% 4 9% 7% 4 5% 4 4 7% 29%	1980
March	1st to 10th	Night	20% 14% 4 13% 6% 4 4 3 4 5% 22%	5364
	11th to 20th	Night	12% 15% 4 10% 6% 6% 5% 4 5% 6% 26%	5276
	21st to end	Night	15% 11% 4 9% 5% 5% 5% 4 5% 5% 30%	4962
April	1st to 10th	Night	21% 13% 4 7% 5% 4 4 3 4 6% 30%	2000
	11th to 20th	Night	18% 9% 3 6% 4 5% 4 3 6% 6% 35%	1953
	21st to end	Night	22% 11% 3 7% 4 3 3 2 5% 5% 35%	1800
May	1st to 10th	Night	23% 10% 4 7% 5% 5% 4 3 5% 6% 28%	3714
	11th to 20th	Night	25% 8% 2 5% 3 4 4 3 5% 7% 33%	3575
	21st to end	Night	19% 9% 4 8% 6% 5% 4 4 6% 7% 29%	3926
June	1st to 10th	Night	20% 7% 3 7% 3 4 4 4 5% 8% 35%	1600
	11th to 20th	Night	17% 7% 3 6% 6% 5% 4 5% 5% 7% 36%	1600
	21st to end	Night	19% 8% 3 6% 5% 5% 4 4 6% 7% 32%	1600
July	1st to 10th	Night	12% 6% 2 7% 6% 5% 6% 6% 8% 9% 33%	3600
	11th to 20th	Night	14% 7% 3 7% 4 4 5% 3 6% 7% 41%	3600
	21st to end	Night	11% 5% 2 5% 5% 4 5% 4 6% 7% 47%	3926
August	1st to 10th	Night	13% 6% 3 7% 4 5% 4 4 6% 9% 38%	2586
	11th to 20th	Night	15% 7% 2 7% 4 4 5% 4 5% 7% 38%	2754
	21st to end	Night	16% 7% 2 7% 5% 4 4 3 5% 8% 38%	3586
September	1st to 10th	Night	12% 7% 2 7% 4 4 4 4 6% 7% 44%	1931
	11th to 20th	Night	15% 6% 2 4 3 4 4 4 5% 6% 48%	2004
	21st to end	Night	17% 6% 2 6% 4 3 3 3 4 6% 44%	2090
October	1st to 10th	Night	19% 8% 3 7% 4 3 4 3 4 6% 40%	2185
	11th to 20th	Night	21% 10% 3 7% 5% 4 5% 3 4 7% 32%	2370
	21st to end	Night	23% 10% 3 8% 5% 4 5% 3 5% 7% 28%	2717
November	1st to 10th	Night	18% 11% 4 9% 5% 4 4 4 6% 5% 31%	2537
	11th to 20th	Night	18% 11% 4 8% 6% 5% 5% 4 6% 6% 28%	2690
	21st to end	Night	20% 17% 4 9% 4 5% 4 3 5% 6% 24%	2800
December	1st to 10th	Night	15% 14% 5% 12% 8% 6% 5% 5% 5% 6% 19%	4733
	11th to 20th	Night	21% 15% 4 10% 6% 5% 5% 3 4 4 23%	5340
	21st to end	Night	19% 17% 5% 11% 5% 4 3 2 3 6% 24%	6996

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	67% 5% 8% 15% 5%	3598
	11th to 20th	Day	63% 4 7% 16% 8% 2	3600
	21st to end	Day	55% 4 7% 17% 16% 1	3960
February	1st to 10th	Day	63% 3 7% 15% 9% 2	1677
	11th to 20th	Day	60% 4 10% 15% 11% 1	1872
	21st to end	Day	61% 4 7% 15% 9% 3	1650
March	1st to 10th	Day	66% 4 6% 10% 11% 3	4479
	11th to 20th	Day	54% 5% 14% 14% 12% 2	4679
	21st to end	Day	55% 3 6% 16% 17% 3	5970
April	1st to 10th	Day	58% 4 9% 14% 13% 3	2400
	11th to 20th	Day	51% 4 8% 22% 12% 3	2395
	21st to end	Day	55% 4 9% 16% 13% 3	2600
May	1st to 10th	Day	57% 5% 8% 16% 12% 1	6280
	11th to 20th	Day	50% 6% 16% 18% 8% 2	6322
	21st to end	Day	56% 6% 9% 14% 14% 2	6949
June	1st to 10th	Day	55% 7% 9% 18% 10% 2	2800
	11th to 20th	Day	47% 7% 12% 22% 11% 2	2800
	21st to end	Day	58% 6% 11% 15% 10% 1	2800
July	1st to 10th	Day	52% 4 13% 24% 6%	6290
	11th to 20th	Day	45% 4 17% 27% 6%	6285
	21st to end	Day	40% 4 17% 31% 8%	6728
August	1st to 10th	Day	47% 6% 18% 21% 7%	4549
	11th to 20th	Day	49% 5% 18% 22% 6%	4299
	21st to end	Day	47% 5% 13% 20% 14%	4312
September	1st to 10th	Day	41% 7% 17% 25% 11% 1	2316
	11th to 20th	Day	40% 6% 14% 29% 10% 1	2176
	21st to end	Day	47% 5% 13% 26% 9%	2090
October	1st to 10th	Day	51% 4 11% 27% 6%	3303
	11th to 20th	Day	54% 4 14% 24% 4	2987
	21st to end	Day	50% 4 20% 19% 6% 1	3081
November	1st to 10th	Day	55% 6% 10% 19% 9% 1	1761
	11th to 20th	Day	58% 5% 10% 18% 9%	1710
	21st to end	Day	64% 5% 10% 16% 6%	1600
December	1st to 10th	Day	69% 2 9% 16% 4	2427
	11th to 20th	Day	59% 4 6% 21% 11%	2843
	21st to end	Day	63% 3 7% 15% 12%	3960
January	1st to 10th	Night	68% 4 11% 14% 4	6349
	11th to 20th	Night	65% 4 10% 15% 5% 1	6360
	21st to end	Night	57% 5% 7% 15% 14%	6996
February	1st to 10th	Night	55% 4 10% 18% 10% 1	2720
	11th to 20th	Night	58% 4 10% 17% 10% 1	2423
	21st to end	Night	55% 4 8% 17% 13% 2	1980
March	1st to 10th	Night	65% 4 7% 10% 12% 2	5374
	11th to 20th	Night	56% 5% 12% 15% 11% 2	5277
	21st to end	Night	54% 3 6% 23% 11% 2	4962
April	1st to 10th	Night	55% 4 8% 16% 16% 2	2000
	11th to 20th	Night	48% 4 9% 23% 13% 2	1953
	21st to end	Night	51% 3 8% 21% 14% 2	1800
May	1st to 10th	Night	57% 4 11% 17% 9% 1	3720
	11th to 20th	Night	50% 5% 13% 20% 9% 2	3576
	21st to end	Night	52% 6% 11% 16% 13% 2	3927
June	1st to 10th	Night	47% 6% 12% 23% 11% 1	1600
	11th to 20th	Night	46% 7% 12% 20% 12% 3	1600
	21st to end	Night	49% 7% 12% 18% 13%	1600
July	1st to 10th	Night	44% 4 24% 22% 6%	3560
	11th to 20th	Night	44% 3 20% 28% 5%	3552
	21st to end	Night	36% 4 19% 31% 10%	3809
August	1st to 10th	Night	44% 5% 18% 24% 9%	2576
	11th to 20th	Night	45% 4 21% 23% 7%	2778
	21st to end	Night	46% 4 14% 25% 11%	3586
September	1st to 10th	Night	38% 6% 18% 26% 12% 1	1931
	11th to 20th	Night	35% 6% 18% 31% 10% 1	2004
	21st to end	Night	41% 5% 12% 30% 12%	2090
October	1st to 10th	Night	50% 3 12% 26% 9%	3640
	11th to 20th	Night	46% 4 15% 29% 7%	3932
	21st to end	Night	49% 3 17% 18% 11% 1	4467
November	1st to 10th	Night	53% 5% 13% 21% 7% 1	2537
	11th to 20th	Night	55% 5% 11% 19% 9% 1	2690
	21st to end	Night	61% 5% 11% 16% 7%	2800
December	1st to 10th	Night	62% 3 15% 15% 4	4733
	11th to 20th	Night	62% 4 6% 19% 8%	5340
	21st to end	Night	63% 3 6% 15% 13% 1	6996

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% 18% 40% 14% 3 1	200
	11th to 20th	Day	26% 17% 37% 15% 6%	200
	21st to end	Day	18% 20% 38% 18% 5%	220
February	1st to 10th	Day	27% 30% 36% 5% 1	239
	11th to 20th	Day	25% 28% 35% 10% 1	411
	21st to end	Day	28% 25% 32% 12% 4	414
March	1st to 10th	Day	26% 20% 35% 16% 4	500
	11th to 20th	Day	26% 24% 32% 13% 4 1	500
	21st to end	Day	29% 24% 27% 14% 5% 2	550
April	1st to 10th	Day	32% 17% 29% 15% 6%	500
	11th to 20th	Day	31% 22% 26% 13% 6% 2	492
	21st to end	Day	32% 21% 32% 11% 4 1	500
May	1st to 10th	Day	30% 18% 32% 13% 6% 1	503
	11th to 20th	Day	21% 18% 33% 19% 6% 2	527
	21st to end	Day	26% 20% 32% 16% 5%	573
June	1st to 10th	Day	25% 15% 35% 20% 6%	530
	11th to 20th	Day	21% 18% 31% 21% 8% 1	530
	21st to end	Day	29% 13% 33% 19% 7%	530
July	1st to 10th	Day	17% 14% 38% 21% 9% 1	525
	11th to 20th	Day	14% 12% 41% 25% 8% 1	524
	21st to end	Day	14% 13% 32% 31% 9% 2	576
August	1st to 10th	Day	15% 10% 30% 29% 13% 2	526
	11th to 20th	Day	18% 7% 29% 28% 14% 4	519
	21st to end	Day	18% 15% 27% 23% 12% 5%	583
September	1st to 10th	Day	19% 15% 30% 21% 10% 5%	502
	11th to 20th	Day	17% 11% 28% 24% 14% 5%	490
	21st to end	Day	22% 15% 28% 18% 12% 4	490
October	1st to 10th	Day	25% 16% 28% 18% 10% 3	490
	11th to 20th	Day	28% 18% 28% 16% 8% 2	443
	21st to end	Day	34% 17% 27% 17% 5%	429
November	1st to 10th	Day	31% 18% 27% 17% 6% 1	395
	11th to 20th	Day	32% 16% 31% 16% 5%	310
	21st to end	Day	27% 24% 32% 16% 2	200
December	1st to 10th	Day	33% 14% 30% 18% 6% 1	200
	11th to 20th	Day	33% 22% 29% 14% 3	200
	21st to end	Day	32% 21% 29% 14% 3 2	220
January	1st to 10th	Night	26% 15% 36% 19% 4	800
	11th to 20th	Night	26% 16% 33% 18% 6%	800
	21st to end	Night	15% 12% 41% 26% 5%	880
February	1st to 10th	Night	19% 15% 37% 24% 4	800
	11th to 20th	Night	21% 18% 38% 19% 4	783
	21st to end	Night	22% 16% 34% 24% 4	660
March	1st to 10th	Night	24% 16% 35% 22% 4	800
	11th to 20th	Night	25% 18% 32% 20% 5% 1	800
	21st to end	Night	24% 16% 32% 21% 7%	880
April	1st to 10th	Night	30% 14% 29% 20% 7%	800
	11th to 20th	Night	25% 14% 32% 22% 7%	769
	21st to end	Night	29% 16% 31% 18% 5%	600
May	1st to 10th	Night	29% 12% 30% 22% 6% 1	455
	11th to 20th	Night	24% 11% 29% 26% 9%	394
	21st to end	Night	22% 10% 36% 24% 9%	433
June	1st to 10th	Night	24% 9% 27% 34% 6%	400
	11th to 20th	Night	21% 9% 26% 34% 10% 1	400
	21st to end	Night	25% 5% 26% 35% 10% 1	400
July	1st to 10th	Night	14% 6% 33% 37% 9%	390
	11th to 20th	Night	15% 4 26% 39% 15%	388
	21st to end	Night	15% 7% 26% 39% 13% 1	438
August	1st to 10th	Night	12% 3 25% 43% 16% 1	398
	11th to 20th	Night	16% 5% 23% 37% 17% 2	509
	21st to end	Night	20% 7% 25% 30% 16% 2	880
September	1st to 10th	Night	15% 8% 30% 34% 13% 1	773
	11th to 20th	Night	19% 8% 27% 27% 19% 2	760
	21st to end	Night	22% 8% 27% 27% 14% 1	760
October	1st to 10th	Night	23% 13% 27% 26% 11%	760
	11th to 20th	Night	28% 11% 30% 21% 8% 1	760
	21st to end	Night	31% 12% 31% 21% 5%	836
November	1st to 10th	Night	25% 15% 27% 26% 6% 1	780
	11th to 20th	Night	25% 16% 31% 19% 8% 1	800
	21st to end	Night	31% 17% 25% 21% 5% 1	800
December	1st to 10th	Night	28% 13% 30% 22% 7%	845
	11th to 20th	Night	29% 15% 32% 17% 5% 1	840
	21st to end	Night	32% 15% 30% 18% 4 1	880

Page generated at 2025-09-01 01:51:06. Version ac07

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