Riviere-du-Loup
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Riviere-du-Loup 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% 10% 3 8% 5% 5% 5% 4 5% 7% 31%	130957
	Night	17% 13% 4 10% 6% 5% 5% 4 5% 6% 27%	130659
Transparency	Day	55% 3 14% 20% 8% 1	134387
	Night	60% 3 12% 18% 7%	135304
Seeing	Day	25% 12% 30% 22% 8% 2	17369
	Night	26% 11% 29% 25% 8% 1	25666

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	15% 22% 5% 11% 6% 5% 6% 4 5% 5% 16%	4222
	11th to 20th	Day	11% 17% 7% 15% 8% 5% 5% 4 5% 6% 17%	4650
	21st to end	Day	4 7% 4 14% 9% 7% 7% 5% 6% 8% 28%	5124
February	1st to 10th	Day	8% 14% 5% 11% 8% 8% 6% 4 6% 7% 23%	1742
	11th to 20th	Day	13% 16% 7% 11% 7% 6% 4 3 4 5% 24%	1917
	21st to end	Day	12% 11% 5% 8% 7% 6% 6% 4 5% 6% 30%	1730
March	1st to 10th	Day	19% 14% 4 9% 5% 4 4 3 5% 6% 26%	4576
	11th to 20th	Day	17% 17% 4 8% 6% 6% 5% 4 5% 6% 23%	4980
	21st to end	Day	17% 17% 4 9% 5% 3 3 3 4 4 31%	5597
April	1st to 10th	Day	20% 12% 4 8% 6% 4 3 4 5% 7% 28%	2400
	11th to 20th	Day	19% 9% 3 7% 4 3 3 3 5% 6% 37%	2561
	21st to end	Day	23% 10% 3 6% 4 4 4 3 5% 6% 34%	2600
May	1st to 10th	Day	20% 9% 3 7% 5% 5% 5% 3 5% 6% 32%	5886
	11th to 20th	Day	22% 9% 3 7% 4 4 4 3 5% 6% 34%	6425
	21st to end	Day	18% 8% 3 7% 5% 4 4 4 6% 8% 32%	7451
June	1st to 10th	Day	19% 9% 3 7% 5% 5% 4 4 5% 7% 33%	3000
	11th to 20th	Day	18% 5% 2 6% 4 4 5% 4 6% 8% 37%	3000
	21st to end	Day	20% 8% 3 8% 5% 5% 4 4 6% 7% 30%	3000
July	1st to 10th	Day	16% 7% 3 8% 5% 5% 5% 5% 7% 8% 31%	6820
	11th to 20th	Day	15% 6% 2 7% 5% 6% 5% 5% 7% 7% 34%	6595
	21st to end	Day	11% 6% 2 7% 4 4 5% 4 6% 8% 44%	6926
August	1st to 10th	Day	14% 6% 3 7% 5% 6% 6% 4 7% 9% 35%	4446
	11th to 20th	Day	17% 7% 3 7% 4 5% 5% 4 7% 8% 33%	4175
	21st to end	Day	17% 6% 2 6% 4 4 4 3 5% 7% 40%	4675
September	1st to 10th	Day	15% 6% 2 5% 4 5% 4 4 5% 9% 41%	2370
	11th to 20th	Day	15% 7% 2 5% 4 3 4 2 5% 6% 48%	2200
	21st to end	Day	18% 6% 2 6% 5% 4 4 3 5% 6% 42%	2200
October	1st to 10th	Day	17% 8% 2 7% 5% 4 5% 4 5% 7% 35%	2146
	11th to 20th	Day	23% 8% 3 7% 5% 4 5% 4 6% 6% 29%	1878
	21st to end	Day	24% 13% 4 7% 4 4 4 3 4 5% 28%	1980
November	1st to 10th	Day	18% 12% 4 8% 6% 5% 5% 4 5% 6% 28%	1851
	11th to 20th	Day	20% 13% 5% 9% 6% 4 3 4 6% 5% 24%	1719
	21st to end	Day	20% 18% 5% 9% 5% 4 4 3 5% 5% 22%	1524
December	1st to 10th	Day	17% 14% 5% 11% 6% 5% 4 4 4 8% 23%	2350
	11th to 20th	Day	19% 16% 3 9% 6% 6% 3 3 4 5% 25%	2688
	21st to end	Day	17% 14% 5% 10% 7% 8% 5% 4 4 5% 23%	3553
January	1st to 10th	Night	14% 20% 6% 13% 7% 6% 5% 4 5% 5% 15%	8693
	11th to 20th	Night	11% 18% 7% 17% 7% 5% 5% 3 5% 5% 17%	8235
	21st to end	Night	4 10% 6% 15% 7% 7% 7% 5% 7% 7% 26%	9057
February	1st to 10th	Night	9% 13% 5% 12% 7% 5% 5% 4 6% 6% 26%	2877
	11th to 20th	Night	12% 18% 6% 13% 7% 4 4 4 4 4 24%	2584
	21st to end	Night	13% 16% 5% 10% 7% 4 4 3 4 6% 29%	2076
March	1st to 10th	Night	20% 14% 4 10% 6% 5% 6% 4 4 5% 23%	5484
	11th to 20th	Night	15% 20% 5% 10% 6% 4 5% 3 5% 6% 21%	5133
	21st to end	Night	21% 18% 4 7% 3 3 3 2 3 5% 31%	5333
April	1st to 10th	Night	23% 15% 4 8% 5% 3 3 3 4 5% 28%	2000
	11th to 20th	Night	21% 10% 4 8% 5% 4 5% 3 4 6% 31%	1788
	21st to end	Night	26% 10% 3 7% 4 4 3 2 5% 5% 32%	1800
May	1st to 10th	Night	22% 8% 2 7% 4 4 4 4 6% 7% 33%	4054
	11th to 20th	Night	25% 9% 3 6% 4 4 5% 4 5% 6% 28%	3490
	21st to end	Night	20% 7% 2 7% 4 4 5% 4 7% 7% 32%	3446
June	1st to 10th	Night	19% 10% 2 8% 6% 6% 4 4 5% 6% 29%	1400
	11th to 20th	Night	18% 7% 2 7% 5% 4 4 4 6% 8% 35%	1400
	21st to end	Night	22% 10% 4 7% 5% 4 4 4 5% 7% 27%	1400
July	1st to 10th	Night	16% 7% 3 9% 5% 6% 5% 5% 6% 9% 30%	3160
	11th to 20th	Night	17% 7% 3 8% 6% 4 4 4 6% 8% 33%	3371
	21st to end	Night	13% 5% 3 7% 4 5% 5% 4 6% 8% 40%	3926
August	1st to 10th	Night	17% 7% 3 7% 6% 5% 5% 4 6% 7% 34%	2671
	11th to 20th	Night	15% 8% 4 11% 7% 5% 7% 5% 6% 7% 25%	2872
	21st to end	Night	18% 7% 3 8% 4 4 3 3 5% 7% 39%	3223
September	1st to 10th	Night	15% 7% 2 7% 4 5% 4 3 5% 7% 40%	2027
	11th to 20th	Night	18% 7% 3 7% 4 4 4 4 4 5% 39%	2200
	21st to end	Night	17% 8% 3 6% 4 3 3 3 4 6% 43%	2200
October	1st to 10th	Night	18% 8% 3 7% 4 3 3 3 5% 6% 40%	2253
	11th to 20th	Night	25% 10% 3 6% 5% 4 5% 3 5% 5% 29%	2520
	21st to end	Night	23% 10% 4 8% 4 4 4 3 5% 7% 27%	2860
November	1st to 10th	Night	21% 14% 3 8% 5% 4 4 3 5% 6% 27%	2667
	11th to 20th	Night	21% 14% 4 7% 5% 4 4 3 5% 5% 28%	2899
	21st to end	Night	20% 18% 5% 9% 6% 5% 4 4 5% 5% 20%	3092
December	1st to 10th	Night	15% 18% 8% 12% 7% 5% 4 3 4 7% 17%	5060
	11th to 20th	Night	20% 16% 4 11% 6% 5% 5% 4 5% 6% 19%	5741
	21st to end	Night	16% 15% 4 11% 8% 7% 6% 4 4 4 21%	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	72% 3 9% 13% 3	4223
	11th to 20th	Day	71% 2 9% 13% 5%	4680
	21st to end	Day	55% 3 14% 17% 12%	5124
February	1st to 10th	Day	60% 3 14% 15% 7% 2	1742
	11th to 20th	Day	65% 2 10% 16% 6%	1925
	21st to end	Day	55% 3 9% 22% 10% 1	1730
March	1st to 10th	Day	61% 2 10% 14% 11% 2	4579
	11th to 20th	Day	64% 3 12% 14% 7%	4980
	21st to end	Day	60% 2 6% 21% 9% 3	5597
April	1st to 10th	Day	58% 3 9% 17% 10% 2	2400
	11th to 20th	Day	51% 3 11% 23% 11% 2	2561
	21st to end	Day	54% 3 8% 20% 13% 2	2600
May	1st to 10th	Day	56% 2 10% 21% 10% 1	5897
	11th to 20th	Day	54% 2 14% 21% 8% 2	6429
	21st to end	Day	51% 3 13% 23% 9% 1	7451
June	1st to 10th	Day	51% 4 10% 22% 11% 1	3000
	11th to 20th	Day	46% 5% 16% 21% 12% 1	3000
	21st to end	Day	53% 4 13% 20% 9% 1	3000
July	1st to 10th	Day	50% 3 16% 25% 6%	6745
	11th to 20th	Day	47% 3 24% 21% 4	6514
	21st to end	Day	40% 3 20% 28% 8%	6728
August	1st to 10th	Day	44% 5% 21% 24% 6%	4432
	11th to 20th	Day	49% 3 21% 22% 4	4214
	21st to end	Day	45% 3 19% 21% 11%	4675
September	1st to 10th	Day	41% 4 17% 28% 10%	2370
	11th to 20th	Day	39% 4 17% 29% 11% 1	2200
	21st to end	Day	45% 3 15% 27% 9%	2200
October	1st to 10th	Day	56% 4 13% 22% 6%	3497
	11th to 20th	Day	58% 3 17% 20% 2	3029
	21st to end	Day	56% 2 15% 22% 5%	3180
November	1st to 10th	Day	59% 3 13% 19% 4	1851
	11th to 20th	Day	63% 4 9% 19% 4	1719
	21st to end	Day	66% 4 12% 14% 4	1524
December	1st to 10th	Day	67% 2 15% 11% 5%	2350
	11th to 20th	Day	61% 3 11% 18% 6%	2688
	21st to end	Day	64% 4 12% 15% 4 1	3553
January	1st to 10th	Night	72% 2 12% 13% 2	8693
	11th to 20th	Night	71% 2 10% 11% 6%	8280
	21st to end	Night	56% 3 9% 21% 11%	9057
February	1st to 10th	Night	58% 4 12% 17% 8% 1	2877
	11th to 20th	Night	66% 3 9% 15% 7%	2587
	21st to end	Night	58% 2 9% 21% 9% 1	2076
March	1st to 10th	Night	65% 2 7% 15% 10%	5494
	11th to 20th	Night	67% 2 11% 13% 6% 1	5134
	21st to end	Night	60% 2 5% 23% 10% 1	5333
April	1st to 10th	Night	62% 3 6% 15% 11% 3	2000
	11th to 20th	Night	56% 3 8% 19% 13% 1	1788
	21st to end	Night	57% 2 7% 20% 13% 1	1800
May	1st to 10th	Night	53% 3 11% 19% 13% 1	4060
	11th to 20th	Night	58% 2 9% 22% 8% 1	3491
	21st to end	Night	51% 3 12% 22% 11% 1	3447
June	1st to 10th	Night	54% 4 10% 20% 11% 1	1400
	11th to 20th	Night	48% 4 13% 19% 14% 2	1400
	21st to end	Night	56% 3 13% 18% 10%	1400
July	1st to 10th	Night	51% 4 17% 24% 4	3125
	11th to 20th	Night	49% 3 25% 20% 3	3329
	21st to end	Night	43% 3 22% 24% 7%	3809
August	1st to 10th	Night	49% 4 18% 23% 5%	2661
	11th to 20th	Night	56% 5% 20% 13% 5%	2899
	21st to end	Night	46% 3 14% 26% 10%	3223
September	1st to 10th	Night	46% 3 13% 27% 10% 1	2027
	11th to 20th	Night	47% 3 16% 24% 9% 1	2200
	21st to end	Night	45% 5% 11% 27% 12% 1	2200
October	1st to 10th	Night	49% 3 11% 29% 6% 1	3682
	11th to 20th	Night	57% 2 14% 23% 4	4095
	21st to end	Night	58% 4 15% 18% 4	4610
November	1st to 10th	Night	61% 4 13% 16% 5%	2667
	11th to 20th	Night	61% 4 12% 17% 6%	2899
	21st to end	Night	68% 4 12% 12% 3	3092
December	1st to 10th	Night	72% 2 12% 12% 3	5060
	11th to 20th	Night	69% 3 8% 17% 3	5742
	21st to end	Night	67% 3 10% 16% 3	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	25% 17% 36% 18% 3 1	220
	11th to 20th	Day	22% 19% 35% 18% 5% 1	220
	21st to end	Day	14% 20% 37% 17% 10% 2	242
February	1st to 10th	Day	19% 23% 28% 22% 6% 3	282
	11th to 20th	Day	21% 19% 38% 19% 3	465
	21st to end	Day	21% 18% 36% 20% 6%	446
March	1st to 10th	Day	28% 14% 31% 23% 5% 1	540
	11th to 20th	Day	28% 14% 28% 20% 7% 2	528
	21st to end	Day	29% 17% 29% 17% 5% 2	550
April	1st to 10th	Day	30% 16% 27% 21% 4 1	500
	11th to 20th	Day	29% 13% 28% 23% 5% 2	492
	21st to end	Day	30% 14% 30% 18% 6% 2	500
May	1st to 10th	Day	28% 15% 29% 18% 9% 1	503
	11th to 20th	Day	25% 12% 29% 24% 9% 2	571
	21st to end	Day	26% 12% 34% 20% 7% 2	790
June	1st to 10th	Day	27% 9% 30% 23% 10% 1	730
	11th to 20th	Day	26% 8% 31% 23% 10% 2	730
	21st to end	Day	25% 6% 30% 26% 12% 1	730
July	1st to 10th	Day	22% 10% 28% 29% 10% 1	720
	11th to 20th	Day	16% 7% 35% 25% 13% 3	623
	21st to end	Day	17% 6% 33% 30% 12% 1	576
August	1st to 10th	Day	17% 9% 29% 29% 13% 3	526
	11th to 20th	Day	18% 5% 27% 31% 15% 3	519
	21st to end	Day	19% 11% 27% 24% 14% 5%	583
September	1st to 10th	Day	20% 10% 28% 26% 12% 4	530
	11th to 20th	Day	21% 10% 28% 25% 11% 5%	530
	21st to end	Day	23% 10% 28% 25% 9% 5%	530
October	1st to 10th	Day	22% 12% 32% 21% 9% 4	500
	11th to 20th	Day	34% 13% 24% 18% 10% 2	420
	21st to end	Day	34% 13% 28% 17% 6% 1	462
November	1st to 10th	Day	36% 15% 30% 16% 2	425
	11th to 20th	Day	33% 13% 27% 19% 6% 1	430
	21st to end	Day	36% 15% 32% 14% 3	274
December	1st to 10th	Day	25% 18% 36% 12% 6% 2	220
	11th to 20th	Day	33% 19% 30% 16% 1	220
	21st to end	Day	29% 23% 24% 20% 4	242
January	1st to 10th	Night	26% 16% 32% 21% 5% 1	925
	11th to 20th	Night	25% 16% 31% 22% 6%	840
	21st to end	Night	15% 12% 35% 28% 8% 1	924
February	1st to 10th	Night	16% 15% 37% 23% 8% 1	840
	11th to 20th	Night	23% 14% 34% 23% 6% 1	823
	21st to end	Night	21% 13% 34% 24% 7% 1	692
March	1st to 10th	Night	24% 12% 34% 22% 7% 1	840
	11th to 20th	Night	29% 14% 31% 19% 7% 1	829
	21st to end	Night	28% 14% 28% 22% 6% 2	880
April	1st to 10th	Night	33% 10% 29% 21% 6% 1	800
	11th to 20th	Night	29% 9% 26% 27% 8%	604
	21st to end	Night	33% 10% 25% 24% 7% 1	600
May	1st to 10th	Night	30% 8% 26% 29% 7% 1	600
	11th to 20th	Night	26% 7% 24% 31% 11% 1	413
	21st to end	Night	29% 9% 27% 25% 9% 1	433
June	1st to 10th	Night	23% 6% 24% 37% 9% 1	400
	11th to 20th	Night	22% 7% 23% 36% 13% 1	400
	21st to end	Night	27% 5% 28% 30% 10% 1	400
July	1st to 10th	Night	21% 6% 28% 33% 11% 1	390
	11th to 20th	Night	19% 5% 26% 36% 13% 1	388
	21st to end	Night	17% 3 26% 39% 13% 1	438
August	1st to 10th	Night	18% 3 21% 41% 17% 1	444
	11th to 20th	Night	18% 3 25% 39% 14% 1	592
	21st to end	Night	18% 6% 26% 34% 14% 2	660
September	1st to 10th	Night	21% 7% 28% 31% 11% 2	787
	11th to 20th	Night	23% 6% 27% 29% 13% 3	800
	21st to end	Night	22% 6% 29% 29% 12% 2	800
October	1st to 10th	Night	26% 8% 29% 26% 9% 2	800
	11th to 20th	Night	33% 10% 25% 23% 10% 1	800
	21st to end	Night	31% 11% 28% 22% 7%	880
November	1st to 10th	Night	34% 13% 29% 19% 5%	820
	11th to 20th	Night	31% 15% 27% 19% 7% 1	929
	21st to end	Night	31% 15% 29% 19% 5%	950
December	1st to 10th	Night	29% 13% 33% 19% 6% 1	950
	11th to 20th	Night	28% 17% 31% 19% 5%	950
	21st to end	Night	28% 15% 29% 21% 6% 1	1045

Page generated at 2026-03-15 02:23:51. Version ac07

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