Parc National du Mont-Orford
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parc National du Mont-Orford clear sky chart from 2005-11-06 to 2026-05-17.

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% 12% 4 10% 6% 5% 5% 4 5% 6% 26%	131809
	Night	16% 13% 5% 12% 6% 5% 5% 3 4 5% 25%	131009
Transparency	Day	57% 6% 11% 17% 8% 1	135277
	Night	60% 6% 10% 16% 8% 1	135628
Seeing	Day	26% 18% 29% 18% 7% 2	16543
	Night	24% 16% 28% 23% 8% 1	25525

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% 17% 9% 21% 8% 9% 4 2 3 3 13%	4661
	11th to 20th	Day	8% 17% 8% 21% 13% 7% 5% 3 4 3 10%	4650
	21st to end	Day	8% 14% 7% 15% 9% 13% 7% 3 5% 4 13%	5124
February	1st to 10th	Day	12% 18% 6% 15% 10% 7% 5% 3 3 4 17%	1766
	11th to 20th	Day	12% 18% 7% 16% 9% 6% 5% 3 4 4 17%	2038
	21st to end	Day	12% 18% 6% 13% 8% 6% 4 3 5% 5% 20%	1730
March	1st to 10th	Day	18% 15% 7% 15% 6% 5% 6% 3 3 3 19%	4576
	11th to 20th	Day	13% 16% 6% 11% 6% 4 4 3 5% 6% 26%	4761
	21st to end	Day	19% 14% 6% 11% 6% 4 3 2 3 4 27%	6055
April	1st to 10th	Day	20% 18% 4 10% 5% 4 3 3 4 4 25%	2520
	11th to 20th	Day	20% 15% 4 8% 4 3 4 3 4 3 32%	2523
	21st to end	Day	23% 12% 3 8% 4 4 4 3 5% 6% 28%	2730
May	1st to 10th	Day	28% 13% 3 9% 5% 4 4 3 5% 5% 21%	6151
	11th to 20th	Day	19% 9% 3 8% 6% 6% 6% 4 5% 7% 28%	6402
	21st to end	Day	20% 9% 3 7% 5% 5% 5% 4 6% 7% 29%	6949
June	1st to 10th	Day	25% 9% 3 6% 5% 4 5% 4 6% 7% 27%	2800
	11th to 20th	Day	17% 7% 2 7% 4 5% 5% 5% 6% 7% 35%	2800
	21st to end	Day	23% 9% 3 6% 5% 4 5% 4 5% 6% 29%	2800
July	1st to 10th	Day	15% 8% 3 8% 6% 5% 6% 5% 7% 9% 27%	6360
	11th to 20th	Day	13% 6% 2 7% 5% 5% 6% 5% 7% 9% 35%	6360
	21st to end	Day	14% 7% 2 6% 4 4 5% 4 6% 9% 40%	6926
August	1st to 10th	Day	17% 8% 3 8% 5% 5% 6% 4 7% 7% 29%	4541
	11th to 20th	Day	17% 7% 3 8% 5% 5% 6% 4 7% 9% 29%	4158
	21st to end	Day	17% 7% 2 7% 4 4 5% 4 7% 7% 36%	4312
September	1st to 10th	Day	14% 7% 3 6% 4 4 5% 4 5% 7% 41%	2400
	11th to 20th	Day	17% 7% 2 6% 3 3 3 3 5% 7% 44%	2252
	21st to end	Day	18% 9% 2 6% 4 4 4 4 6% 8% 36%	2200
October	1st to 10th	Day	22% 10% 2 6% 5% 5% 4 3 6% 6% 31%	2160
	11th to 20th	Day	20% 13% 3 7% 5% 5% 5% 3 5% 6% 28%	1890
	21st to end	Day	25% 18% 4 7% 4 4 4 3 3 4 24%	1980
November	1st to 10th	Day	18% 17% 4 8% 5% 4 4 3 4 5% 27%	1851
	11th to 20th	Day	15% 18% 8% 11% 5% 4 4 3 4 5% 23%	1890
	21st to end	Day	18% 20% 7% 12% 6% 5% 3 3 5% 6% 16%	1699
December	1st to 10th	Day	14% 23% 8% 19% 9% 4 4 2 3 3 11%	2680
	11th to 20th	Day	18% 17% 7% 14% 5% 4 4 3 4 4 20%	3066
	21st to end	Day	19% 17% 6% 14% 5% 5% 4 3 4 5% 18%	4048
January	1st to 10th	Night	11% 18% 8% 20% 9% 7% 4 3 3 3 14%	8234
	11th to 20th	Night	9% 17% 9% 20% 12% 7% 5% 3 3 3 10%	8235
	21st to end	Night	8% 13% 6% 14% 10% 11% 7% 4 5% 4 17%	9057
February	1st to 10th	Night	11% 17% 5% 17% 8% 6% 5% 3 4 5% 19%	2851
	11th to 20th	Night	11% 15% 6% 16% 9% 7% 5% 3 5% 4 20%	2468
	21st to end	Night	12% 18% 5% 12% 8% 5% 4 3 3 4 26%	2076
March	1st to 10th	Night	18% 15% 5% 12% 5% 6% 5% 3 4 4 23%	5484
	11th to 20th	Night	14% 15% 5% 12% 6% 5% 4 3 5% 6% 24%	5418
	21st to end	Night	15% 15% 6% 13% 8% 5% 4 3 4 3 25%	5102
April	1st to 10th	Night	22% 13% 4 7% 6% 5% 4 3 4 5% 27%	2100
	11th to 20th	Night	20% 13% 4 7% 4 4 4 3 4 5% 31%	2045
	21st to end	Night	21% 11% 2 8% 5% 4 4 3 5% 5% 32%	1890
May	1st to 10th	Night	26% 12% 4 9% 5% 5% 4 3 4 5% 23%	4053
	11th to 20th	Night	23% 8% 3 7% 5% 5% 5% 4 5% 7% 30%	3623
	21st to end	Night	18% 10% 3 8% 5% 5% 5% 3 5% 7% 33%	3926
June	1st to 10th	Night	26% 8% 2 6% 3 4 4 3 5% 8% 31%	1600
	11th to 20th	Night	18% 7% 2 6% 4 4 4 5% 7% 8% 35%	1600
	21st to end	Night	19% 9% 2 6% 5% 4 5% 4 6% 8% 31%	1600
July	1st to 10th	Night	13% 8% 3 9% 7% 5% 7% 5% 6% 8% 30%	3600
	11th to 20th	Night	17% 7% 2 6% 4 4 5% 4 6% 7% 38%	3600
	21st to end	Night	12% 7% 2 7% 5% 5% 5% 5% 6% 8% 40%	3926
August	1st to 10th	Night	21% 9% 3 6% 4 3 4 4 5% 6% 35%	2586
	11th to 20th	Night	14% 6% 3 8% 5% 6% 5% 5% 6% 8% 34%	2863
	21st to end	Night	16% 7% 2 6% 4 4 5% 4 5% 7% 40%	3586
September	1st to 10th	Night	15% 6% 3 6% 4 5% 4 3 5% 7% 42%	2000
	11th to 20th	Night	15% 6% 2 6% 3 3 3 4 5% 7% 47%	2146
	21st to end	Night	19% 7% 2 5% 4 3 4 3 5% 7% 41%	2200
October	1st to 10th	Night	20% 9% 2 6% 5% 4 4 4 6% 6% 35%	2237
	11th to 20th	Night	19% 10% 4 9% 5% 5% 5% 3 4 5% 31%	2509
	21st to end	Night	23% 12% 4 8% 4 4 4 3 5% 5% 26%	2860
November	1st to 10th	Night	18% 15% 4 7% 5% 5% 5% 3 5% 6% 27%	2667
	11th to 20th	Night	16% 14% 7% 10% 6% 4 4 2 5% 5% 27%	2730
	21st to end	Night	17% 17% 8% 14% 5% 4 4 3 4 5% 21%	2919
December	1st to 10th	Night	15% 22% 9% 19% 7% 5% 4 3 3 3 10%	4720
	11th to 20th	Night	19% 19% 6% 16% 7% 5% 3 3 4 4 15%	5348
	21st to end	Night	19% 17% 5% 12% 7% 5% 5% 2 4 5% 19%	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	78% 4 8% 8% 2	4662
	11th to 20th	Day	78% 5% 6% 8% 4	4680
	21st to end	Day	73% 4 6% 9% 7%	5124
February	1st to 10th	Day	72% 5% 6% 12% 5% 1	1766
	11th to 20th	Day	71% 5% 9% 10% 4 1	2047
	21st to end	Day	66% 6% 8% 13% 6% 2	1730
March	1st to 10th	Day	69% 6% 7% 9% 7% 3	4579
	11th to 20th	Day	58% 5% 13% 12% 10% 1	4761
	21st to end	Day	61% 4 7% 13% 14% 1	6055
April	1st to 10th	Day	63% 4 8% 16% 8% 1	2520
	11th to 20th	Day	56% 5% 7% 18% 13% 1	2523
	21st to end	Day	57% 6% 9% 17% 9% 2	2730
May	1st to 10th	Day	64% 6% 9% 15% 5% 1	6162
	11th to 20th	Day	53% 9% 15% 15% 7% 1	6406
	21st to end	Day	50% 9% 12% 19% 9% 1	6949
June	1st to 10th	Day	53% 8% 12% 17% 8% 1	2800
	11th to 20th	Day	46% 7% 12% 22% 11% 1	2800
	21st to end	Day	54% 8% 11% 19% 8% 1	2800
July	1st to 10th	Day	50% 8% 14% 21% 8%	6290
	11th to 20th	Day	42% 9% 13% 28% 7%	6285
	21st to end	Day	40% 7% 12% 33% 8%	6728
August	1st to 10th	Day	51% 8% 15% 20% 6%	4527
	11th to 20th	Day	48% 8% 18% 19% 6%	4197
	21st to end	Day	45% 6% 15% 20% 12% 2	4312
September	1st to 10th	Day	41% 8% 14% 28% 10% 1	2400
	11th to 20th	Day	40% 6% 12% 28% 13%	2252
	21st to end	Day	45% 7% 14% 23% 11% 1	2200
October	1st to 10th	Day	47% 6% 14% 25% 8%	3524
	11th to 20th	Day	51% 6% 13% 24% 6%	3054
	21st to end	Day	54% 4 14% 20% 8% 1	3180
November	1st to 10th	Day	58% 8% 10% 17% 6%	1851
	11th to 20th	Day	65% 5% 9% 12% 8% 1	1890
	21st to end	Day	69% 6% 12% 10% 2	1699
December	1st to 10th	Day	79% 4 8% 7% 2	2680
	11th to 20th	Day	68% 4 8% 15% 5%	3066
	21st to end	Day	69% 5% 7% 10% 9%	4048
January	1st to 10th	Night	75% 5% 8% 9% 3	8234
	11th to 20th	Night	78% 5% 6% 7% 3	8280
	21st to end	Night	68% 5% 7% 10% 9%	9057
February	1st to 10th	Night	68% 6% 8% 13% 5%	2851
	11th to 20th	Night	67% 6% 8% 13% 6%	2470
	21st to end	Night	63% 4 9% 14% 9% 1	2076
March	1st to 10th	Night	63% 6% 8% 12% 9% 2	5494
	11th to 20th	Night	60% 7% 13% 12% 7% 1	5419
	21st to end	Night	64% 4 5% 16% 10% 1	5102
April	1st to 10th	Night	59% 5% 9% 16% 11% 1	2100
	11th to 20th	Night	54% 6% 9% 18% 12% 1	2045
	21st to end	Night	53% 6% 9% 17% 12% 2	1890
May	1st to 10th	Night	62% 7% 10% 15% 6% 1	4059
	11th to 20th	Night	52% 9% 12% 18% 7% 1	3624
	21st to end	Night	51% 8% 11% 18% 12%	3927
June	1st to 10th	Night	51% 8% 11% 21% 9% 1	1600
	11th to 20th	Night	45% 8% 13% 21% 11% 2	1600
	21st to end	Night	50% 8% 14% 19% 9% 1	1600
July	1st to 10th	Night	48% 8% 17% 19% 7%	3560
	11th to 20th	Night	44% 7% 13% 28% 8%	3552
	21st to end	Night	41% 7% 16% 27% 9%	3809
August	1st to 10th	Night	48% 6% 15% 24% 5%	2576
	11th to 20th	Night	46% 9% 18% 20% 7%	2890
	21st to end	Night	43% 7% 13% 23% 13% 1	3586
September	1st to 10th	Night	40% 8% 14% 25% 12%	2000
	11th to 20th	Night	36% 7% 16% 29% 12% 1	2146
	21st to end	Night	43% 8% 12% 24% 12% 1	2200
October	1st to 10th	Night	49% 6% 11% 25% 9%	3653
	11th to 20th	Night	50% 6% 11% 24% 9%	4084
	21st to end	Night	52% 5% 13% 19% 9% 1	4610
November	1st to 10th	Night	58% 6% 12% 17% 6% 1	2667
	11th to 20th	Night	59% 6% 11% 14% 8% 2	2730
	21st to end	Night	67% 6% 11% 13% 4	2919
December	1st to 10th	Night	81% 5% 6% 6% 2	4720
	11th to 20th	Night	73% 4 5% 10% 7%	5348
	21st to end	Night	68% 5% 7% 12% 7%	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	25% 26% 29% 17% 3	220
	11th to 20th	Day	25% 29% 33% 9% 4 1	220
	21st to end	Day	29% 22% 29% 14% 5%	242
February	1st to 10th	Day	32% 28% 27% 10% 3	266
	11th to 20th	Day	27% 27% 32% 13% 1	526
	21st to end	Day	29% 25% 30% 15% 1	446
March	1st to 10th	Day	31% 22% 31% 13% 3	540
	11th to 20th	Day	32% 24% 28% 13% 3 1	540
	21st to end	Day	34% 24% 23% 13% 6% 1	594
April	1st to 10th	Day	37% 19% 25% 14% 4 1	540
	11th to 20th	Day	37% 18% 26% 12% 5% 2	532
	21st to end	Day	32% 20% 30% 11% 6% 1	540
May	1st to 10th	Day	35% 18% 25% 15% 5% 1	543
	11th to 20th	Day	23% 18% 32% 20% 7% 2	551
	21st to end	Day	21% 21% 31% 20% 6% 1	573
June	1st to 10th	Day	27% 16% 32% 18% 5% 1	530
	11th to 20th	Day	21% 17% 32% 21% 8% 1	530
	21st to end	Day	24% 16% 36% 16% 6% 2	530
July	1st to 10th	Day	17% 14% 34% 23% 10% 2	525
	11th to 20th	Day	15% 11% 41% 25% 6% 3	524
	21st to end	Day	17% 11% 38% 24% 9% 1	576
August	1st to 10th	Day	16% 10% 29% 30% 13% 2	526
	11th to 20th	Day	17% 9% 29% 27% 14% 3	519
	21st to end	Day	19% 15% 26% 23% 10% 6%	583
September	1st to 10th	Day	17% 13% 31% 21% 13% 5%	530
	11th to 20th	Day	16% 12% 22% 22% 19% 8%	530
	21st to end	Day	19% 15% 27% 22% 13% 4	530
October	1st to 10th	Day	23% 16% 25% 20% 12% 4	530
	11th to 20th	Day	28% 20% 24% 18% 10% 1	469
	21st to end	Day	36% 19% 25% 16% 5%	462
November	1st to 10th	Day	33% 21% 27% 16% 3	425
	11th to 20th	Day	28% 23% 27% 15% 5% 1	430
	21st to end	Day	33% 24% 30% 11% 2	239
December	1st to 10th	Day	30% 24% 26% 16% 3 1	220
	11th to 20th	Day	30% 26% 33% 10%	220
	21st to end	Day	33% 24% 27% 12% 3 1	242
January	1st to 10th	Night	27% 22% 32% 17% 2	840
	11th to 20th	Night	25% 22% 33% 16% 4	840
	21st to end	Night	21% 19% 33% 21% 5%	924
February	1st to 10th	Night	22% 20% 33% 21% 4	840
	11th to 20th	Night	22% 23% 33% 19% 3	823
	21st to end	Night	26% 18% 32% 23% 2	692
March	1st to 10th	Night	29% 19% 30% 19% 3	840
	11th to 20th	Night	29% 19% 27% 19% 6%	840
	21st to end	Night	26% 20% 27% 21% 6% 1	924
April	1st to 10th	Night	32% 15% 29% 19% 4	840
	11th to 20th	Night	28% 18% 26% 23% 5%	801
	21st to end	Night	29% 18% 28% 19% 6%	630
May	1st to 10th	Night	26% 12% 32% 23% 7% 1	591
	11th to 20th	Night	21% 13% 29% 28% 8% 1	406
	21st to end	Night	20% 11% 32% 29% 8%	433
June	1st to 10th	Night	30% 7% 27% 28% 9%	400
	11th to 20th	Night	21% 9% 26% 31% 13%	400
	21st to end	Night	19% 8% 32% 31% 10%	400
July	1st to 10th	Night	13% 7% 29% 37% 14%	390
	11th to 20th	Night	13% 4 27% 40% 15% 2	388
	21st to end	Night	13% 6% 28% 39% 14%	438
August	1st to 10th	Night	17% 5% 17% 41% 19%	398
	11th to 20th	Night	14% 7% 24% 35% 20% 1	583
	21st to end	Night	16% 7% 24% 34% 17% 2	880
September	1st to 10th	Night	17% 8% 26% 33% 14% 1	800
	11th to 20th	Night	17% 9% 19% 31% 22% 3	800
	21st to end	Night	21% 10% 27% 26% 15% 1	800
October	1st to 10th	Night	24% 12% 24% 26% 13% 1	800
	11th to 20th	Night	26% 16% 25% 23% 9% 1	800
	21st to end	Night	28% 18% 28% 23% 4	880
November	1st to 10th	Night	29% 17% 30% 19% 5%	820
	11th to 20th	Night	26% 21% 28% 16% 8% 1	840
	21st to end	Night	28% 24% 27% 15% 5% 1	840
December	1st to 10th	Night	31% 22% 27% 15% 4	840
	11th to 20th	Night	28% 22% 30% 16% 4	840
	21st to end	Night	32% 23% 25% 17% 3	924

Page generated at 2026-05-14 01:58:59. Version ac07

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