Saguenay-Bagotville Airport (YBG)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Saguenay-Bagotville Airport (YBG) clear sky chart from 2005-11-06 to 2026-03-18.

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% 11% 4 10% 6% 6% 5% 4 5% 6% 25%	131039
	Night	16% 14% 5% 12% 7% 6% 5% 4 5% 5% 21%	130583
Transparency	Day	58% 7% 13% 16% 6%	134461
	Night	63% 7% 11% 15% 5%	135248
Seeing	Day	25% 17% 29% 20% 8% 2	17085
	Night	25% 15% 28% 24% 7% 1	25527

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% 20% 7% 18% 8% 6% 8% 4 3 3 11%	4409
	11th to 20th	Day	8% 17% 8% 19% 14% 7% 7% 4 5% 4 9%	4650
	21st to end	Day	4 9% 6% 17% 9% 10% 8% 5% 7% 6% 19%	5124
February	1st to 10th	Day	6% 13% 5% 12% 9% 10% 9% 6% 7% 6% 17%	1680
	11th to 20th	Day	10% 17% 6% 14% 9% 8% 6% 4 5% 5% 17%	1947
	21st to end	Day	8% 14% 5% 10% 9% 8% 8% 5% 6% 6% 23%	1730
March	1st to 10th	Day	14% 16% 5% 9% 5% 4 4 4 6% 6% 28%	4576
	11th to 20th	Day	15% 16% 5% 12% 7% 6% 5% 4 5% 6% 20%	4840
	21st to end	Day	12% 16% 5% 11% 6% 6% 4 3 4 6% 26%	5785
April	1st to 10th	Day	18% 15% 4 11% 6% 5% 4 3 5% 6% 25%	2400
	11th to 20th	Day	19% 12% 3 8% 5% 4 4 3 4 6% 32%	2507
	21st to end	Day	21% 11% 3 7% 5% 4 4 4 6% 7% 29%	2600
May	1st to 10th	Day	22% 12% 3 7% 4 4 4 3 4 6% 30%	6149
	11th to 20th	Day	23% 8% 3 7% 6% 5% 5% 3 5% 5% 30%	6318
	21st to end	Day	18% 9% 3 7% 5% 5% 5% 4 6% 7% 30%	7397
June	1st to 10th	Day	21% 8% 2 7% 5% 5% 5% 4 6% 7% 30%	3000
	11th to 20th	Day	17% 8% 3 8% 6% 5% 5% 5% 6% 7% 32%	3000
	21st to end	Day	22% 8% 3 8% 6% 4 5% 5% 5% 6% 28%	3000
July	1st to 10th	Day	19% 8% 3 8% 5% 5% 5% 5% 6% 8% 26%	6820
	11th to 20th	Day	16% 7% 3 9% 6% 6% 6% 5% 7% 8% 28%	6413
	21st to end	Day	13% 6% 3 7% 5% 5% 5% 5% 6% 9% 37%	6926
August	1st to 10th	Day	15% 7% 3 8% 6% 6% 6% 5% 8% 9% 28%	4563
	11th to 20th	Day	19% 6% 3 9% 6% 5% 6% 4 7% 9% 27%	4206
	21st to end	Day	19% 8% 3 8% 5% 5% 5% 4 5% 6% 33%	4557
September	1st to 10th	Day	19% 7% 2 8% 5% 6% 6% 3 6% 7% 32%	2400
	11th to 20th	Day	20% 6% 2 7% 4 4 4 3 6% 7% 37%	2220
	21st to end	Day	22% 9% 3 7% 4 4 4 4 5% 7% 33%	2200
October	1st to 10th	Day	20% 9% 3 8% 5% 6% 4 3 6% 7% 30%	2190
	11th to 20th	Day	26% 15% 3 9% 7% 5% 5% 3 4 5% 18%	1800
	21st to end	Day	25% 16% 4 9% 5% 4 3 4 4 5% 20%	1980
November	1st to 10th	Day	19% 17% 5% 11% 7% 5% 5% 4 4 4 20%	1851
	11th to 20th	Day	20% 20% 7% 11% 5% 5% 4 4 4 4 17%	1740
	21st to end	Day	18% 22% 6% 13% 8% 4 4 3 4 5% 12%	1470
December	1st to 10th	Day	12% 19% 8% 16% 11% 7% 6% 4 4 5% 9%	2350
	11th to 20th	Day	17% 15% 7% 15% 11% 7% 4 4 4 5% 12%	2688
	21st to end	Day	16% 16% 5% 12% 9% 8% 8% 5% 5% 5% 12%	3553
January	1st to 10th	Night	11% 22% 7% 16% 9% 8% 8% 4 3 3 7%	8494
	11th to 20th	Night	7% 21% 9% 23% 10% 5% 5% 4 4 4 9%	8235
	21st to end	Night	4 9% 5% 14% 10% 9% 9% 7% 9% 6% 17%	9057
February	1st to 10th	Night	8% 13% 5% 13% 9% 9% 7% 5% 5% 7% 20%	2940
	11th to 20th	Night	10% 21% 7% 14% 8% 6% 5% 3 4 4 17%	2556
	21st to end	Night	11% 17% 6% 12% 8% 6% 5% 3 4 5% 24%	2076
March	1st to 10th	Night	17% 18% 5% 12% 6% 4 6% 4 4 5% 18%	5484
	11th to 20th	Night	14% 17% 5% 12% 6% 6% 6% 4 6% 7% 17%	5274
	21st to end	Night	15% 17% 5% 11% 5% 4 4 3 4 5% 29%	5146
April	1st to 10th	Night	20% 17% 4 9% 6% 4 4 3 4 4 25%	2000
	11th to 20th	Night	21% 13% 3 7% 4 4 3 3 5% 6% 30%	1842
	21st to end	Night	22% 12% 2 6% 4 4 4 3 5% 5% 32%	1800
May	1st to 10th	Night	23% 10% 3 6% 4 3 4 3 6% 6% 31%	3834
	11th to 20th	Night	24% 9% 3 8% 5% 4 4 4 4 6% 30%	3575
	21st to end	Night	20% 8% 3 7% 4 4 4 4 5% 7% 32%	3496
June	1st to 10th	Night	19% 8% 3 7% 5% 5% 6% 4 6% 6% 29%	1400
	11th to 20th	Night	18% 9% 3 6% 5% 4 5% 3 5% 7% 34%	1400
	21st to end	Night	22% 9% 3 7% 5% 5% 4 4 6% 7% 27%	1400
July	1st to 10th	Night	17% 8% 3 8% 6% 6% 5% 5% 6% 7% 27%	3160
	11th to 20th	Night	17% 7% 3 8% 5% 6% 6% 6% 8% 9% 26%	3546
	21st to end	Night	16% 7% 3 8% 4 5% 5% 4 6% 7% 35%	3926
August	1st to 10th	Night	16% 7% 3 9% 5% 6% 6% 5% 7% 8% 29%	2586
	11th to 20th	Night	18% 8% 3 9% 5% 5% 6% 5% 6% 8% 27%	2809
	21st to end	Night	17% 7% 3 8% 5% 5% 5% 4 6% 7% 32%	3338
September	1st to 10th	Night	20% 7% 3 7% 5% 4 4 4 6% 6% 36%	2000
	11th to 20th	Night	20% 7% 2 7% 5% 5% 5% 4 5% 6% 34%	2179
	21st to end	Night	22% 8% 3 6% 4 5% 5% 4 4 5% 36%	2200
October	1st to 10th	Night	21% 9% 3 6% 5% 4 4 3 5% 6% 34%	2207
	11th to 20th	Night	28% 14% 3 8% 5% 4 4 3 4 5% 21%	2600
	21st to end	Night	26% 15% 4 9% 5% 4 4 3 5% 6% 20%	2860
November	1st to 10th	Night	24% 17% 6% 9% 5% 4 3 3 4 5% 20%	2667
	11th to 20th	Night	19% 20% 6% 12% 6% 5% 4 3 5% 5% 17%	2878
	21st to end	Night	19% 23% 7% 14% 7% 6% 4 3 3 3 12%	3150
December	1st to 10th	Night	13% 16% 9% 19% 11% 6% 5% 4 4 4 9%	5060
	11th to 20th	Night	17% 17% 6% 16% 9% 6% 4 4 4 4 12%	5741
	21st to end	Night	14% 20% 6% 13% 7% 5% 5% 3 4 4 17%	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	77% 6% 8% 8% 1	4410
	11th to 20th	Day	78% 5% 7% 7% 4	4680
	21st to end	Day	63% 5% 8% 17% 7%	5124
February	1st to 10th	Day	64% 9% 9% 13% 6% 1	1680
	11th to 20th	Day	69% 6% 10% 11% 4	1955
	21st to end	Day	59% 8% 11% 16% 5% 1	1730
March	1st to 10th	Day	57% 6% 13% 12% 11% 1	4579
	11th to 20th	Day	65% 7% 12% 10% 7%	4840
	21st to end	Day	59% 5% 9% 18% 8% 1	5785
April	1st to 10th	Day	62% 5% 10% 14% 6% 2	2400
	11th to 20th	Day	53% 6% 13% 19% 8% 1	2507
	21st to end	Day	54% 8% 12% 16% 10% 1	2600
May	1st to 10th	Day	54% 7% 12% 17% 10% 1	6160
	11th to 20th	Day	53% 9% 11% 18% 8% 1	6322
	21st to end	Day	49% 8% 13% 18% 11% 1	7397
June	1st to 10th	Day	53% 8% 11% 17% 10% 1	3000
	11th to 20th	Day	49% 8% 13% 19% 10% 1	3000
	21st to end	Day	54% 9% 12% 17% 8% 1	3000
July	1st to 10th	Day	53% 7% 13% 24% 3	6745
	11th to 20th	Day	51% 8% 19% 19% 3	6336
	21st to end	Day	43% 7% 18% 25% 7%	6728
August	1st to 10th	Day	49% 9% 18% 20% 3	4549
	11th to 20th	Day	52% 7% 23% 15% 3	4246
	21st to end	Day	52% 7% 15% 18% 8% 1	4557
September	1st to 10th	Day	50% 8% 16% 20% 6%	2400
	11th to 20th	Day	45% 7% 20% 22% 6%	2220
	21st to end	Day	52% 8% 14% 20% 6%	2200
October	1st to 10th	Day	57% 6% 11% 21% 4	3567
	11th to 20th	Day	66% 6% 14% 12% 1	2912
	21st to end	Day	63% 6% 14% 15% 2	3180
November	1st to 10th	Day	67% 7% 13% 11% 2	1851
	11th to 20th	Day	70% 8% 9% 10% 2	1740
	21st to end	Day	76% 8% 11% 5% 1	1470
December	1st to 10th	Day	77% 4 11% 7% 1	2350
	11th to 20th	Day	75% 5% 12% 6% 2	2688
	21st to end	Day	70% 9% 7% 11% 3	3553
January	1st to 10th	Night	81% 6% 7% 6% 1	8494
	11th to 20th	Night	79% 5% 7% 7% 2	8280
	21st to end	Night	62% 6% 10% 16% 6%	9057
February	1st to 10th	Night	61% 7% 10% 15% 6%	2940
	11th to 20th	Night	69% 6% 9% 12% 4	2558
	21st to end	Night	62% 4 11% 16% 6%	2076
March	1st to 10th	Night	67% 5% 9% 12% 7%	5494
	11th to 20th	Night	64% 9% 11% 10% 5%	5275
	21st to end	Night	57% 6% 8% 19% 9% 1	5146
April	1st to 10th	Night	62% 5% 8% 15% 8% 2	2000
	11th to 20th	Night	55% 6% 9% 19% 12%	1842
	21st to end	Night	52% 7% 9% 20% 10% 2	1800
May	1st to 10th	Night	52% 8% 9% 19% 12% 1	3840
	11th to 20th	Night	53% 7% 10% 22% 8% 1	3576
	21st to end	Night	49% 8% 13% 17% 13% 1	3497
June	1st to 10th	Night	52% 9% 11% 19% 8% 2	1400
	11th to 20th	Night	48% 6% 13% 18% 11% 3	1400
	21st to end	Night	54% 9% 12% 18% 8%	1400
July	1st to 10th	Night	53% 7% 13% 22% 5%	3125
	11th to 20th	Night	51% 9% 19% 18% 2	3500
	21st to end	Night	47% 7% 16% 22% 6%	3809
August	1st to 10th	Night	48% 10% 19% 18% 4	2576
	11th to 20th	Night	53% 11% 18% 14% 4	2835
	21st to end	Night	49% 9% 12% 25% 5%	3338
September	1st to 10th	Night	47% 9% 15% 21% 8%	2000
	11th to 20th	Night	50% 8% 16% 20% 6%	2179
	21st to end	Night	50% 8% 12% 22% 8%	2200
October	1st to 10th	Night	54% 5% 12% 24% 4 1	3610
	11th to 20th	Night	64% 5% 12% 16% 3	4227
	21st to end	Night	65% 6% 14% 13% 3	4610
November	1st to 10th	Night	67% 7% 13% 10% 3	2667
	11th to 20th	Night	70% 6% 10% 11% 3	2878
	21st to end	Night	78% 5% 9% 6% 1	3150
December	1st to 10th	Night	79% 5% 9% 6% 1	5060
	11th to 20th	Night	76% 5% 6% 12% 1	5742
	21st to end	Night	70% 7% 8% 14% 2	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	24% 21% 34% 18% 3	220
	11th to 20th	Day	22% 20% 30% 20% 7% 1	220
	21st to end	Day	14% 22% 32% 23% 6% 2	242
February	1st to 10th	Day	15% 21% 44% 13% 5% 2	220
	11th to 20th	Day	24% 22% 34% 16% 4	468
	21st to end	Day	22% 22% 32% 18% 6%	446
March	1st to 10th	Day	29% 16% 32% 18% 5%	540
	11th to 20th	Day	29% 21% 30% 14% 6% 1	528
	21st to end	Day	28% 20% 29% 17% 5%	550
April	1st to 10th	Day	32% 20% 27% 18% 3 1	500
	11th to 20th	Day	30% 17% 28% 18% 5% 1	492
	21st to end	Day	28% 19% 32% 15% 5% 1	500
May	1st to 10th	Day	30% 19% 28% 15% 7% 1	503
	11th to 20th	Day	22% 15% 32% 23% 7% 1	527
	21st to end	Day	27% 17% 29% 19% 7% 1	761
June	1st to 10th	Day	25% 14% 30% 24% 7% 1	730
	11th to 20th	Day	21% 15% 30% 22% 11% 1	730
	21st to end	Day	22% 14% 29% 24% 9% 1	730
July	1st to 10th	Day	22% 13% 29% 27% 9%	720
	11th to 20th	Day	20% 12% 32% 25% 9% 2	549
	21st to end	Day	18% 14% 31% 26% 11% 1	576
August	1st to 10th	Day	21% 10% 27% 26% 10% 5%	526
	11th to 20th	Day	17% 13% 25% 28% 14% 4	519
	21st to end	Day	23% 14% 26% 20% 13% 5%	583
September	1st to 10th	Day	22% 15% 29% 19% 10% 5%	530
	11th to 20th	Day	22% 15% 26% 22% 10% 5%	530
	21st to end	Day	25% 18% 23% 19% 12% 2	530
October	1st to 10th	Day	22% 16% 28% 20% 11% 3	530
	11th to 20th	Day	34% 18% 24% 14% 9% 1	420
	21st to end	Day	35% 20% 23% 17% 5% 1	462
November	1st to 10th	Day	37% 21% 24% 15% 3	425
	11th to 20th	Day	31% 18% 25% 19% 6% 1	376
	21st to end	Day	35% 22% 30% 12% 2	220
December	1st to 10th	Day	25% 15% 35% 19% 6%	220
	11th to 20th	Day	27% 25% 30% 10% 7% 1	220
	21st to end	Day	26% 27% 22% 19% 5% 1	242
January	1st to 10th	Night	25% 16% 32% 21% 5%	889
	11th to 20th	Night	24% 16% 27% 24% 8% 1	840
	21st to end	Night	15% 14% 35% 28% 7% 1	924
February	1st to 10th	Night	13% 17% 37% 25% 7% 1	840
	11th to 20th	Night	23% 18% 30% 22% 6%	823
	21st to end	Night	21% 16% 33% 23% 7% 1	692
March	1st to 10th	Night	25% 16% 34% 21% 4	840
	11th to 20th	Night	25% 18% 31% 17% 8%	829
	21st to end	Night	23% 20% 30% 23% 5% 1	880
April	1st to 10th	Night	29% 17% 29% 21% 4 1	800
	11th to 20th	Night	28% 15% 29% 23% 5%	658
	21st to end	Night	29% 15% 31% 21% 5%	600
May	1st to 10th	Night	31% 13% 29% 22% 5%	510
	11th to 20th	Night	22% 10% 31% 28% 8%	394
	21st to end	Night	27% 12% 29% 24% 7%	433
June	1st to 10th	Night	20% 9% 34% 31% 6% 1	400
	11th to 20th	Night	18% 12% 26% 32% 12% 1	400
	21st to end	Night	22% 10% 29% 32% 7% 1	400
July	1st to 10th	Night	23% 8% 29% 30% 9%	390
	11th to 20th	Night	16% 7% 25% 39% 12%	388
	21st to end	Night	21% 6% 26% 34% 11%	438
August	1st to 10th	Night	17% 8% 23% 38% 13% 1	398
	11th to 20th	Night	20% 8% 22% 33% 16% 1	553
	21st to end	Night	22% 9% 24% 31% 12% 1	723
September	1st to 10th	Night	23% 13% 25% 28% 11% 1	800
	11th to 20th	Night	25% 9% 28% 24% 13% 2	800
	21st to end	Night	25% 12% 26% 26% 10% 2	800
October	1st to 10th	Night	25% 13% 26% 26% 10% 1	800
	11th to 20th	Night	34% 15% 23% 20% 8% 1	800
	21st to end	Night	36% 16% 23% 20% 5%	880
November	1st to 10th	Night	36% 16% 23% 18% 5% 1	820
	11th to 20th	Night	28% 20% 26% 19% 7% 1	890
	21st to end	Night	30% 19% 28% 17% 5% 1	950
December	1st to 10th	Night	30% 15% 26% 21% 7% 1	950
	11th to 20th	Night	26% 19% 27% 20% 6% 1	950
	21st to end	Night	25% 19% 27% 22% 6% 1	1045

Page generated at 2026-03-15 02:23:55. Version ac07

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