Campement Péribonka
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Campement Péribonka clear sky chart from 2005-11-06 to 2026-04-02.

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% 13% 4 11% 6% 6% 5% 4 5% 6% 23%	131375
	Night	14% 14% 5% 12% 7% 6% 5% 4 5% 5% 22%	130571
Transparency	Day	61% 6% 11% 16% 6% 1	134769
	Night	63% 6% 10% 15% 6%	135265
Seeing	Day	25% 16% 30% 19% 9% 2	17170
	Night	24% 13% 29% 25% 9% 1	25526

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	9% 20% 9% 20% 7% 5% 6% 4 4 3 13%	4190
	11th to 20th	Day	7% 15% 6% 22% 14% 11% 7% 4 4 2 8%	4650
	21st to end	Day	3 8% 4 18% 9% 7% 7% 7% 9% 5% 24%	5124
February	1st to 10th	Day	5% 13% 5% 12% 9% 10% 8% 5% 7% 6% 21%	1680
	11th to 20th	Day	8% 19% 5% 15% 10% 7% 5% 4 5% 4 18%	1887
	21st to end	Day	8% 15% 5% 12% 9% 6% 8% 5% 5% 6% 20%	1730
March	1st to 10th	Day	13% 17% 6% 12% 6% 5% 6% 5% 4 4 22%	4576
	11th to 20th	Day	14% 19% 7% 14% 7% 6% 5% 4 4 5% 15%	4850
	21st to end	Day	11% 18% 6% 12% 7% 7% 4 3 5% 5% 22%	5953
April	1st to 10th	Day	16% 19% 5% 12% 6% 4 5% 3 4 5% 21%	2412
	11th to 20th	Day	15% 15% 4 9% 5% 4 5% 4 5% 6% 28%	2520
	21st to end	Day	20% 14% 4 8% 5% 4 4 4 4 5% 28%	2600
May	1st to 10th	Day	19% 14% 4 8% 6% 4 5% 3 5% 6% 26%	6271
	11th to 20th	Day	26% 9% 3 8% 5% 4 4 4 4 5% 27%	6407
	21st to end	Day	16% 11% 3 8% 6% 5% 5% 4 6% 7% 29%	7451
June	1st to 10th	Day	22% 9% 3 7% 6% 5% 4 4 5% 6% 29%	3000
	11th to 20th	Day	18% 8% 3 8% 6% 6% 5% 5% 6% 8% 29%	3000
	21st to end	Day	24% 9% 3 8% 5% 4 5% 3 6% 7% 26%	3000
July	1st to 10th	Day	20% 10% 3 7% 5% 5% 5% 4 6% 8% 27%	6820
	11th to 20th	Day	18% 9% 3 8% 6% 5% 5% 4 7% 9% 27%	6600
	21st to end	Day	15% 7% 3 7% 5% 5% 6% 4 7% 10% 32%	6926
August	1st to 10th	Day	16% 9% 3 8% 5% 5% 6% 5% 8% 9% 24%	4563
	11th to 20th	Day	18% 10% 3 8% 5% 5% 6% 5% 7% 7% 25%	4272
	21st to end	Day	18% 8% 3 9% 5% 5% 5% 4 5% 6% 31%	4587
September	1st to 10th	Day	22% 10% 3 9% 5% 4 4 3 5% 6% 29%	2400
	11th to 20th	Day	23% 10% 3 8% 5% 4 3 3 5% 6% 31%	2235
	21st to end	Day	25% 13% 3 8% 5% 5% 4 3 4 4 27%	2200
October	1st to 10th	Day	22% 14% 4 7% 5% 4 5% 3 5% 6% 26%	2159
	11th to 20th	Day	29% 19% 5% 9% 5% 4 4 3 3 4 15%	1800
	21st to end	Day	27% 20% 5% 9% 5% 3 3 3 3 4 17%	1980
November	1st to 10th	Day	22% 21% 7% 13% 5% 4 4 2 2 3 15%	1851
	11th to 20th	Day	20% 21% 8% 14% 6% 5% 4 2 3 4 13%	1620
	21st to end	Day	19% 26% 9% 13% 6% 4 3 2 3 4 10%	1470
December	1st to 10th	Day	13% 17% 7% 21% 13% 6% 4 2 2 2 13%	2350
	11th to 20th	Day	14% 17% 5% 18% 10% 9% 6% 3 4 3 12%	2688
	21st to end	Day	13% 16% 6% 12% 8% 8% 9% 4 5% 5% 13%	3553
January	1st to 10th	Night	10% 21% 9% 18% 7% 7% 6% 4 4 4 11%	8711
	11th to 20th	Night	7% 17% 8% 21% 11% 8% 6% 3 5% 4 10%	8235
	21st to end	Night	3 8% 4 12% 10% 10% 10% 8% 9% 6% 19%	9057
February	1st to 10th	Night	7% 11% 5% 13% 9% 7% 8% 6% 6% 6% 22%	2940
	11th to 20th	Night	7% 17% 7% 14% 7% 6% 7% 6% 6% 4 18%	2616
	21st to end	Night	8% 13% 7% 14% 8% 7% 6% 5% 5% 5% 21%	2076
March	1st to 10th	Night	14% 15% 5% 12% 7% 6% 5% 5% 5% 5% 21%	5484
	11th to 20th	Night	14% 19% 6% 11% 7% 6% 6% 5% 5% 5% 16%	5329
	21st to end	Night	11% 18% 6% 13% 5% 5% 4 3 4 5% 27%	5218
April	1st to 10th	Night	18% 16% 5% 10% 7% 5% 5% 3 2 5% 24%	2011
	11th to 20th	Night	17% 13% 4 9% 5% 4 4 3 5% 6% 31%	1828
	21st to end	Night	20% 12% 4 8% 5% 5% 4 3 4 6% 29%	1800
May	1st to 10th	Night	18% 11% 4 8% 5% 4 4 3 4 6% 33%	3700
	11th to 20th	Night	24% 9% 3 7% 5% 4 4 3 4 6% 30%	3488
	21st to end	Night	19% 9% 3 7% 4 4 5% 3 5% 6% 34%	3446
June	1st to 10th	Night	19% 9% 4 6% 6% 4 4 5% 7% 6% 30%	1400
	11th to 20th	Night	16% 10% 3 8% 6% 5% 4 5% 5% 7% 31%	1400
	21st to end	Night	19% 11% 3 7% 5% 4 5% 4 6% 6% 31%	1400
July	1st to 10th	Night	16% 7% 4 9% 7% 7% 6% 5% 6% 7% 28%	3160
	11th to 20th	Night	17% 8% 3 9% 7% 5% 5% 5% 8% 8% 25%	3366
	21st to end	Night	14% 6% 3 6% 3 5% 5% 4 6% 9% 40%	3926
August	1st to 10th	Night	16% 8% 3 8% 5% 5% 5% 4 6% 8% 31%	2586
	11th to 20th	Night	17% 8% 4 7% 6% 5% 5% 5% 6% 9% 30%	2743
	21st to end	Night	15% 6% 3 7% 6% 4 5% 4 6% 7% 37%	3307
September	1st to 10th	Night	19% 8% 3 8% 4 4 4 4 4 6% 36%	2000
	11th to 20th	Night	21% 9% 3 6% 5% 4 5% 4 5% 6% 33%	2165
	21st to end	Night	21% 8% 3 6% 5% 4 4 3 5% 6% 34%	2200
October	1st to 10th	Night	19% 11% 3 7% 5% 4 5% 3 5% 6% 33%	2237
	11th to 20th	Night	27% 15% 5% 8% 6% 4 4 3 4 4 22%	2600
	21st to end	Night	27% 17% 4 10% 5% 4 4 3 5% 4 17%	2860
November	1st to 10th	Night	24% 19% 7% 12% 6% 4 3 3 4 4 15%	2667
	11th to 20th	Night	18% 20% 7% 14% 6% 4 4 3 3 4 16%	2997
	21st to end	Night	19% 23% 8% 16% 6% 5% 4 3 3 3 10%	3150
December	1st to 10th	Night	11% 15% 8% 23% 12% 7% 4 3 3 4 10%	5060
	11th to 20th	Night	17% 18% 7% 16% 9% 6% 4 3 4 4 14%	5741
	21st to end	Night	13% 19% 7% 13% 6% 6% 5% 3 6% 6% 15%	7667

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	76% 4 7% 10% 2	4191
	11th to 20th	Day	82% 4 4 5% 4	4680
	21st to end	Day	58% 5% 8% 21% 8%	5124
February	1st to 10th	Day	62% 5% 8% 14% 10% 1	1680
	11th to 20th	Day	67% 5% 9% 11% 7%	1895
	21st to end	Day	62% 5% 9% 16% 8% 1	1730
March	1st to 10th	Day	65% 4 7% 12% 10% 1	4579
	11th to 20th	Day	72% 6% 6% 8% 7%	4850
	21st to end	Day	65% 3 7% 13% 11% 1	5953
April	1st to 10th	Day	67% 5% 7% 12% 8% 1	2412
	11th to 20th	Day	56% 5% 9% 18% 10% 1	2520
	21st to end	Day	59% 5% 8% 16% 11% 1	2600
May	1st to 10th	Day	56% 9% 10% 16% 9% 2	6282
	11th to 20th	Day	57% 8% 9% 17% 8% 2	6411
	21st to end	Day	51% 7% 11% 20% 11% 1	7451
June	1st to 10th	Day	54% 6% 10% 17% 12% 1	3000
	11th to 20th	Day	52% 6% 12% 18% 10% 1	3000
	21st to end	Day	56% 7% 11% 16% 10%	3000
July	1st to 10th	Day	53% 6% 11% 25% 4	6745
	11th to 20th	Day	52% 8% 17% 19% 5%	6519
	21st to end	Day	46% 7% 18% 24% 4	6728
August	1st to 10th	Day	52% 8% 18% 20% 3	4549
	11th to 20th	Day	55% 8% 18% 16% 3	4314
	21st to end	Day	52% 7% 13% 19% 8%	4587
September	1st to 10th	Day	55% 7% 14% 19% 6%	2400
	11th to 20th	Day	54% 7% 16% 19% 5%	2235
	21st to end	Day	61% 7% 11% 17% 5%	2200
October	1st to 10th	Day	59% 6% 12% 18% 4 1	3510
	11th to 20th	Day	72% 5% 10% 11% 1	2912
	21st to end	Day	70% 6% 13% 9% 2	3180
November	1st to 10th	Day	76% 4 10% 7% 3	1851
	11th to 20th	Day	76% 6% 8% 8% 2	1620
	21st to end	Day	80% 5% 8% 7% 1	1470
December	1st to 10th	Day	81% 3 6% 8% 1	2350
	11th to 20th	Day	77% 5% 7% 8% 3	2688
	21st to end	Day	72% 7% 7% 9% 5% 1	3553
January	1st to 10th	Night	78% 4 6% 10% 2	8711
	11th to 20th	Night	78% 3 6% 9% 4	8280
	21st to end	Night	60% 6% 10% 18% 6%	9057
February	1st to 10th	Night	61% 4 11% 15% 8%	2940
	11th to 20th	Night	66% 6% 10% 13% 5%	2619
	21st to end	Night	63% 6% 8% 17% 6%	2076
March	1st to 10th	Night	63% 5% 9% 14% 9% 1	5494
	11th to 20th	Night	69% 5% 8% 11% 6% 1	5330
	21st to end	Night	60% 5% 6% 18% 11%	5218
April	1st to 10th	Night	65% 4 7% 14% 8% 2	2011
	11th to 20th	Night	54% 4 10% 18% 13% 1	1828
	21st to end	Night	56% 6% 8% 18% 10% 2	1800
May	1st to 10th	Night	51% 7% 9% 19% 13%	3706
	11th to 20th	Night	53% 7% 9% 21% 9%	3489
	21st to end	Night	49% 6% 11% 22% 12% 1	3447
June	1st to 10th	Night	51% 6% 13% 18% 11% 2	1400
	11th to 20th	Night	53% 8% 11% 16% 12% 2	1400
	21st to end	Night	52% 9% 10% 19% 10% 1	1400
July	1st to 10th	Night	54% 8% 11% 20% 7%	3125
	11th to 20th	Night	54% 8% 17% 16% 5%	3324
	21st to end	Night	41% 7% 18% 28% 6%	3809
August	1st to 10th	Night	49% 9% 20% 20% 2	2576
	11th to 20th	Night	50% 9% 23% 15% 3	2767
	21st to end	Night	44% 8% 15% 25% 7%	3307
September	1st to 10th	Night	49% 7% 17% 19% 7%	2000
	11th to 20th	Night	52% 7% 17% 17% 5%	2165
	21st to end	Night	51% 7% 13% 22% 7%	2200
October	1st to 10th	Night	55% 5% 14% 21% 4 1	3666
	11th to 20th	Night	64% 6% 10% 17% 3	4227
	21st to end	Night	71% 6% 11% 9% 2 1	4610
November	1st to 10th	Night	74% 5% 10% 8% 3	2667
	11th to 20th	Night	73% 5% 10% 10% 3	2997
	21st to end	Night	81% 5% 7% 6% 1	3150
December	1st to 10th	Night	80% 4 7% 8% 1	5060
	11th to 20th	Night	75% 4 8% 11% 2	5742
	21st to end	Night	69% 5% 7% 14% 4 1	7667

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	17% 13% 38% 24% 7% 1	220
	11th to 20th	Day	16% 17% 35% 18% 10% 3	220
	21st to end	Day	14% 14% 36% 23% 11% 2	242
February	1st to 10th	Day	10% 18% 37% 21% 10% 4	220
	11th to 20th	Day	17% 19% 37% 19% 9%	416
	21st to end	Day	20% 18% 36% 19% 7% 1	446
March	1st to 10th	Day	22% 16% 32% 19% 9% 1	540
	11th to 20th	Day	24% 17% 32% 18% 8% 2	540
	21st to end	Day	23% 18% 31% 20% 6% 2	594
April	1st to 10th	Day	25% 18% 31% 17% 7% 2	504
	11th to 20th	Day	24% 17% 29% 19% 8% 3	492
	21st to end	Day	26% 18% 34% 14% 6% 2	500
May	1st to 10th	Day	29% 15% 26% 20% 9% 1	503
	11th to 20th	Day	20% 16% 31% 21% 10% 2	564
	21st to end	Day	26% 19% 29% 17% 7% 1	790
June	1st to 10th	Day	27% 13% 29% 22% 8% 1	730
	11th to 20th	Day	22% 17% 27% 22% 11% 2	730
	21st to end	Day	27% 12% 29% 21% 10% 1	730
July	1st to 10th	Day	23% 12% 30% 25% 9% 1	720
	11th to 20th	Day	25% 9% 29% 25% 11% 2	628
	21st to end	Day	22% 15% 26% 25% 10% 1	576
August	1st to 10th	Day	26% 10% 28% 23% 11% 3	526
	11th to 20th	Day	20% 12% 28% 22% 15% 4	519
	21st to end	Day	25% 12% 28% 18% 12% 5%	583
September	1st to 10th	Day	27% 15% 29% 17% 9% 3	530
	11th to 20th	Day	27% 14% 27% 20% 9% 4	530
	21st to end	Day	27% 18% 25% 18% 10% 3	530
October	1st to 10th	Day	25% 17% 30% 17% 8% 3	526
	11th to 20th	Day	37% 19% 23% 11% 6% 3	420
	21st to end	Day	39% 17% 23% 14% 7% 1	462
November	1st to 10th	Day	34% 21% 32% 9% 4 1	425
	11th to 20th	Day	29% 19% 27% 17% 7% 1	312
	21st to end	Day	32% 21% 34% 10% 3 1	220
December	1st to 10th	Day	22% 11% 33% 21% 9% 5%	220
	11th to 20th	Day	27% 18% 31% 15% 8% 2	220
	21st to end	Day	20% 20% 30% 21% 9% 1	242
January	1st to 10th	Night	19% 14% 35% 25% 6%	928
	11th to 20th	Night	20% 16% 31% 22% 10% 1	840
	21st to end	Night	13% 9% 34% 32% 10% 2	924
February	1st to 10th	Night	10% 14% 34% 29% 11% 2	840
	11th to 20th	Night	16% 16% 33% 27% 8% 1	823
	21st to end	Night	13% 17% 31% 29% 9% 1	692
March	1st to 10th	Night	16% 15% 36% 25% 8%	840
	11th to 20th	Night	22% 17% 28% 24% 9% 1	840
	21st to end	Night	19% 16% 31% 26% 6% 1	924
April	1st to 10th	Night	27% 13% 27% 25% 7%	805
	11th to 20th	Night	24% 12% 30% 26% 8% 1	644
	21st to end	Night	24% 13% 33% 24% 7% 1	600
May	1st to 10th	Night	26% 10% 28% 27% 9%	454
	11th to 20th	Night	24% 9% 32% 26% 8% 1	394
	21st to end	Night	26% 14% 28% 26% 6%	433
June	1st to 10th	Night	23% 8% 32% 29% 9% 1	400
	11th to 20th	Night	20% 11% 28% 29% 12% 1	400
	21st to end	Night	21% 9% 26% 34% 9% 1	400
July	1st to 10th	Night	24% 6% 28% 33% 9%	390
	11th to 20th	Night	19% 7% 28% 30% 15%	388
	21st to end	Night	21% 7% 25% 34% 13% 1	438
August	1st to 10th	Night	25% 6% 21% 32% 16% 1	398
	11th to 20th	Night	23% 5% 26% 30% 16% 1	511
	21st to end	Night	25% 7% 23% 28% 15% 2	705
September	1st to 10th	Night	24% 11% 27% 25% 12% 1	800
	11th to 20th	Night	28% 11% 25% 25% 10% 2	800
	21st to end	Night	27% 11% 27% 25% 9% 1	800
October	1st to 10th	Night	28% 12% 30% 20% 8% 1	800
	11th to 20th	Night	36% 13% 22% 21% 8% 1	800
	21st to end	Night	37% 13% 23% 19% 7%	880
November	1st to 10th	Night	36% 17% 27% 15% 4 1	820
	11th to 20th	Night	27% 18% 26% 21% 7% 1	920
	21st to end	Night	31% 17% 29% 16% 6%	950
December	1st to 10th	Night	24% 16% 28% 22% 9% 2	950
	11th to 20th	Night	25% 18% 28% 20% 8% 1	950
	21st to end	Night	24% 16% 25% 25% 8% 2	1045

Page generated at 2026-03-30 02:18:44. Version ac07

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