Chicoutimi
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chicoutimi clear sky chart from 2005-11-06 to 2026-10-14.

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% 5% 6% 4 6% 7% 25%	150147
	Night	16% 14% 5% 11% 7% 5% 5% 4 5% 6% 21%	141711
Transparency	Day	57% 7% 12% 17% 6%	153571
	Night	62% 7% 10% 15% 5%	146376
Seeing	Day	24% 17% 29% 20% 9% 2	17964
	Night	25% 14% 28% 25% 8% 1	26118

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% 8% 18% 7% 7% 7% 4 4 3 10%	4395
	11th to 20th	Day	8% 18% 8% 19% 12% 6% 8% 4 5% 4 9%	4650
	21st to end	Day	4 8% 6% 17% 9% 9% 8% 6% 7% 6% 20%	5124
February	1st to 10th	Day	6% 13% 5% 12% 9% 11% 8% 5% 7% 6% 18%	1680
	11th to 20th	Day	11% 16% 6% 14% 9% 8% 5% 4 5% 5% 17%	1942
	21st to end	Day	8% 14% 5% 10% 8% 8% 8% 5% 6% 6% 23%	1730
March	1st to 10th	Day	14% 16% 5% 10% 4 4 5% 5% 5% 6% 26%	4576
	11th to 20th	Day	14% 17% 6% 12% 7% 5% 5% 4 5% 6% 20%	4869
	21st to end	Day	12% 15% 5% 11% 7% 6% 5% 4 5% 6% 25%	5930
April	1st to 10th	Day	18% 14% 4 11% 6% 4 4 3 5% 5% 26%	2520
	11th to 20th	Day	18% 9% 3 7% 6% 5% 5% 3 5% 7% 31%	2634
	21st to end	Day	19% 11% 3 7% 5% 4 5% 3 6% 6% 31%	2730
May	1st to 10th	Day	21% 11% 3 8% 5% 5% 5% 4 6% 7% 27%	7992
	11th to 20th	Day	22% 8% 3 8% 5% 5% 5% 4 5% 7% 29%	8221
	21st to end	Day	19% 9% 3 7% 5% 5% 5% 4 5% 7% 30%	9650
June	1st to 10th	Day	19% 8% 3 7% 6% 4 5% 4 6% 7% 31%	3150
	11th to 20th	Day	18% 6% 3 8% 6% 5% 5% 5% 6% 7% 31%	3150
	21st to end	Day	21% 9% 3 7% 6% 5% 5% 4 6% 7% 27%	3150
July	1st to 10th	Day	16% 8% 3 8% 5% 5% 6% 5% 7% 9% 27%	8880
	11th to 20th	Day	16% 8% 3 9% 5% 5% 5% 4 7% 8% 29%	8350
	21st to end	Day	15% 7% 3 8% 6% 5% 6% 5% 7% 8% 31%	8993
August	1st to 10th	Day	16% 7% 3 8% 6% 5% 6% 5% 7% 9% 29%	6483
	11th to 20th	Day	17% 7% 3 9% 6% 6% 6% 5% 7% 8% 26%	6005
	21st to end	Day	15% 7% 3 10% 6% 6% 5% 4 6% 8% 31%	6432
September	1st to 10th	Day	19% 8% 3 7% 5% 6% 6% 4 5% 8% 30%	2520
	11th to 20th	Day	19% 6% 2 7% 4 4 6% 4 6% 7% 35%	2336
	21st to end	Day	21% 8% 3 7% 6% 5% 4 3 5% 7% 33%	2310
October	1st to 10th	Day	20% 8% 3 8% 5% 6% 5% 4 5% 6% 29%	2294
	11th to 20th	Day	26% 14% 3 8% 7% 5% 6% 3 5% 5% 17%	1829
	21st to end	Day	25% 16% 5% 8% 4 4 4 3 5% 5% 20%	1980
November	1st to 10th	Day	20% 15% 5% 10% 7% 5% 5% 4 4 5% 19%	1851
	11th to 20th	Day	21% 18% 6% 12% 6% 4 4 3 4 5% 16%	1730
	21st to end	Day	18% 24% 6% 13% 8% 5% 5% 3 4 4 11%	1470
December	1st to 10th	Day	14% 18% 8% 15% 11% 6% 5% 4 4 4 11%	2350
	11th to 20th	Day	17% 15% 7% 14% 10% 7% 6% 5% 4 6% 11%	2688
	21st to end	Day	16% 17% 6% 13% 8% 7% 7% 4 6% 5% 12%	3553
January	1st to 10th	Night	12% 22% 9% 15% 9% 8% 7% 4 4 4 8%	8495
	11th to 20th	Night	8% 22% 9% 22% 9% 5% 5% 3 3 4 9%	8235
	21st to end	Night	4 10% 6% 13% 10% 9% 9% 7% 9% 7% 16%	9057
February	1st to 10th	Night	8% 13% 5% 13% 9% 7% 7% 5% 6% 6% 21%	2940
	11th to 20th	Night	10% 20% 7% 14% 8% 6% 5% 3 5% 4 18%	2562
	21st to end	Night	10% 16% 5% 12% 8% 6% 5% 3 5% 6% 24%	2076
March	1st to 10th	Night	18% 16% 6% 11% 6% 4 6% 4 5% 6% 18%	5484
	11th to 20th	Night	14% 16% 5% 12% 6% 7% 6% 4 6% 6% 18%	5309
	21st to end	Night	13% 17% 5% 11% 5% 4 4 3 4 6% 27%	5242
April	1st to 10th	Night	21% 15% 5% 8% 6% 4 4 3 3 5% 25%	2100
	11th to 20th	Night	21% 13% 4 7% 5% 4 4 4 4 5% 31%	1935
	21st to end	Night	20% 12% 2 7% 4 4 4 3 4 5% 33%	1890
May	1st to 10th	Night	22% 10% 3 7% 4 4 4 4 5% 6% 31%	4962
	11th to 20th	Night	23% 10% 4 9% 5% 4 4 4 5% 6% 28%	4639
	21st to end	Night	20% 9% 4 8% 5% 4 4 4 5% 7% 30%	4551
June	1st to 10th	Night	19% 8% 4 7% 5% 4 5% 4 6% 7% 30%	1470
	11th to 20th	Night	18% 9% 3 7% 5% 4 5% 4 5% 7% 33%	1470
	21st to end	Night	21% 8% 3 8% 5% 6% 4 4 6% 7% 28%	1470
July	1st to 10th	Night	18% 7% 3 8% 5% 5% 6% 4 6% 8% 29%	4110
	11th to 20th	Night	17% 8% 3 8% 5% 6% 6% 5% 7% 8% 26%	4597
	21st to end	Night	17% 8% 4 8% 5% 5% 5% 4 6% 7% 31%	5084
August	1st to 10th	Night	20% 7% 4 8% 5% 5% 6% 5% 6% 8% 28%	3666
	11th to 20th	Night	17% 8% 3 9% 6% 6% 6% 5% 7% 7% 25%	3994
	21st to end	Night	15% 7% 3 9% 5% 6% 6% 4 6% 8% 32%	4690
September	1st to 10th	Night	20% 7% 3 7% 5% 4 4 4 6% 7% 33%	2100
	11th to 20th	Night	19% 7% 3 8% 5% 5% 5% 4 6% 5% 33%	2284
	21st to end	Night	21% 7% 2 8% 5% 5% 5% 4 4 5% 34%	2310
October	1st to 10th	Night	22% 8% 3 7% 4 5% 4 4 5% 6% 32%	2322
	11th to 20th	Night	29% 13% 3 8% 5% 4 5% 3 5% 5% 20%	2637
	21st to end	Night	27% 15% 3 8% 5% 5% 4 4 5% 6% 19%	2860
November	1st to 10th	Night	25% 17% 4 9% 6% 4 4 3 5% 5% 19%	2667
	11th to 20th	Night	20% 20% 5% 12% 4 4 5% 3 5% 5% 18%	2885
	21st to end	Night	20% 23% 6% 13% 7% 4 4 3 4 4 12%	3150
December	1st to 10th	Night	14% 17% 8% 20% 11% 6% 5% 4 4 3 8%	5060
	11th to 20th	Night	19% 18% 6% 16% 8% 5% 5% 4 4 5% 11%	5741
	21st to end	Night	15% 20% 6% 12% 7% 6% 6% 2 4 7% 14%	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% 7% 8% 7% 1	4396
	11th to 20th	Day	77% 6% 7% 6% 3	4680
	21st to end	Day	63% 6% 8% 17% 7%	5124
February	1st to 10th	Day	63% 9% 8% 13% 6% 1	1680
	11th to 20th	Day	69% 6% 9% 11% 4	1950
	21st to end	Day	59% 7% 10% 17% 6% 1	1730
March	1st to 10th	Day	57% 7% 11% 14% 10% 1	4579
	11th to 20th	Day	65% 6% 11% 10% 7%	4869
	21st to end	Day	59% 5% 9% 18% 9% 2	5930
April	1st to 10th	Day	62% 5% 11% 13% 7% 2	2520
	11th to 20th	Day	54% 6% 12% 20% 9% 1	2634
	21st to end	Day	53% 7% 10% 18% 10% 1	2730
May	1st to 10th	Day	54% 7% 11% 18% 9% 1	8004
	11th to 20th	Day	53% 9% 9% 20% 9% 1	8225
	21st to end	Day	52% 7% 10% 16% 13% 1	9651
June	1st to 10th	Day	52% 7% 11% 19% 11% 1	3150
	11th to 20th	Day	49% 8% 12% 18% 11% 1	3150
	21st to end	Day	54% 8% 12% 17% 8% 1	3150
July	1st to 10th	Day	48% 8% 15% 25% 4	8805
	11th to 20th	Day	49% 8% 17% 22% 4	8273
	21st to end	Day	49% 8% 17% 21% 6%	8795
August	1st to 10th	Day	48% 9% 17% 22% 4	6469
	11th to 20th	Day	51% 9% 21% 17% 3	6045
	21st to end	Day	48% 8% 18% 19% 7%	6432
September	1st to 10th	Day	51% 7% 15% 20% 7%	2520
	11th to 20th	Day	45% 8% 19% 21% 6%	2336
	21st to end	Day	51% 8% 14% 21% 7%	2310
October	1st to 10th	Day	56% 8% 12% 20% 4	3671
	11th to 20th	Day	66% 7% 13% 13% 1	2941
	21st to end	Day	61% 8% 15% 13% 2	3180
November	1st to 10th	Day	67% 7% 10% 12% 3	1851
	11th to 20th	Day	71% 7% 9% 9% 3	1730
	21st to end	Day	76% 8% 10% 5% 1	1470
December	1st to 10th	Day	77% 5% 11% 6% 1	2350
	11th to 20th	Day	74% 6% 11% 7% 2	2688
	21st to end	Day	69% 10% 6% 10% 4	3553
January	1st to 10th	Night	80% 7% 7% 6% 1	8495
	11th to 20th	Night	79% 5% 6% 7% 3	8280
	21st to end	Night	61% 8% 10% 16% 6%	9057
February	1st to 10th	Night	60% 7% 10% 16% 7%	2940
	11th to 20th	Night	69% 6% 9% 11% 5%	2564
	21st to end	Night	62% 4 10% 18% 6%	2076
March	1st to 10th	Night	67% 6% 8% 13% 6%	5494
	11th to 20th	Night	63% 9% 10% 12% 6%	5310
	21st to end	Night	58% 5% 7% 19% 10% 1	5242
April	1st to 10th	Night	62% 5% 8% 15% 8% 2	2100
	11th to 20th	Night	56% 5% 8% 18% 12% 1	1935
	21st to end	Night	53% 6% 8% 21% 10% 2	1890
May	1st to 10th	Night	52% 8% 9% 19% 11% 1	4968
	11th to 20th	Night	54% 7% 9% 21% 8%	4640
	21st to end	Night	51% 7% 10% 16% 15% 2	4552
June	1st to 10th	Night	52% 9% 10% 20% 9% 1	1470
	11th to 20th	Night	48% 6% 13% 18% 12% 3	1470
	21st to end	Night	54% 9% 10% 17% 9%	1470
July	1st to 10th	Night	50% 7% 13% 23% 7%	4075
	11th to 20th	Night	50% 9% 17% 20% 3	4551
	21st to end	Night	50% 9% 16% 20% 6%	4967
August	1st to 10th	Night	51% 9% 18% 18% 4	3656
	11th to 20th	Night	53% 11% 18% 15% 3	4020
	21st to end	Night	46% 9% 15% 24% 4	4690
September	1st to 10th	Night	47% 9% 14% 21% 8%	2100
	11th to 20th	Night	50% 7% 16% 21% 6%	2284
	21st to end	Night	50% 8% 11% 23% 9%	2310
October	1st to 10th	Night	54% 7% 13% 21% 5% 1	3725
	11th to 20th	Night	63% 8% 10% 15% 4	4264
	21st to end	Night	64% 8% 14% 10% 3	4610
November	1st to 10th	Night	67% 7% 12% 10% 3	2667
	11th to 20th	Night	70% 6% 10% 11% 3	2885
	21st to end	Night	77% 6% 9% 6% 2	3150
December	1st to 10th	Night	78% 6% 10% 5% 1	5060
	11th to 20th	Night	75% 5% 6% 11% 2	5742
	21st to end	Night	70% 6% 7% 13% 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	23% 20% 35% 18% 4	220
	11th to 20th	Day	20% 18% 31% 23% 6% 1	220
	21st to end	Day	15% 19% 32% 26% 6% 2	242
February	1st to 10th	Day	14% 19% 45% 15% 6% 2	220
	11th to 20th	Day	21% 21% 35% 18% 5%	463
	21st to end	Day	21% 22% 31% 19% 6% 1	446
March	1st to 10th	Day	27% 16% 32% 18% 6%	540
	11th to 20th	Day	28% 19% 31% 16% 6% 1	540
	21st to end	Day	27% 20% 28% 18% 6%	594
April	1st to 10th	Day	30% 19% 28% 18% 4 1	540
	11th to 20th	Day	27% 17% 28% 20% 7% 1	532
	21st to end	Day	25% 19% 31% 16% 7% 1	540
May	1st to 10th	Day	29% 17% 29% 17% 7% 1	543
	11th to 20th	Day	21% 18% 29% 23% 8% 1	567
	21st to end	Day	26% 18% 29% 19% 8% 1	817
June	1st to 10th	Day	23% 15% 29% 23% 8% 1	780
	11th to 20th	Day	21% 14% 28% 23% 12% 2	780
	21st to end	Day	24% 13% 27% 23% 11% 2	780
July	1st to 10th	Day	21% 11% 30% 26% 10% 1	770
	11th to 20th	Day	19% 14% 30% 25% 10% 2	593
	21st to end	Day	18% 12% 30% 23% 13% 2	620
August	1st to 10th	Day	19% 11% 26% 27% 13% 4	566
	11th to 20th	Day	17% 10% 25% 29% 16% 4	559
	21st to end	Day	21% 15% 26% 20% 13% 5%	627
September	1st to 10th	Day	21% 16% 30% 19% 9% 5%	570
	11th to 20th	Day	22% 15% 27% 21% 11% 5%	570
	21st to end	Day	25% 15% 22% 21% 12% 5%	570
October	1st to 10th	Day	22% 18% 26% 20% 11% 3	570
	11th to 20th	Day	34% 18% 23% 14% 8% 2	429
	21st to end	Day	35% 19% 24% 17% 5% 1	462
November	1st to 10th	Day	35% 20% 25% 15% 4	425
	11th to 20th	Day	30% 18% 25% 20% 6% 1	367
	21st to end	Day	33% 22% 30% 12% 3	220
December	1st to 10th	Day	24% 15% 35% 18% 6% 1	220
	11th to 20th	Day	27% 22% 32% 10% 7% 2	220
	21st to end	Day	24% 28% 22% 19% 6% 1	242
January	1st to 10th	Night	25% 15% 32% 23% 5%	889
	11th to 20th	Night	25% 15% 26% 25% 9% 1	840
	21st to end	Night	15% 13% 33% 30% 8% 1	924
February	1st to 10th	Night	14% 15% 36% 26% 7% 1	840
	11th to 20th	Night	22% 18% 31% 22% 6%	823
	21st to end	Night	20% 16% 30% 25% 8% 1	692
March	1st to 10th	Night	23% 16% 33% 23% 5%	840
	11th to 20th	Night	25% 17% 30% 18% 9%	840
	21st to end	Night	22% 19% 29% 24% 5% 1	924
April	1st to 10th	Night	29% 16% 30% 19% 5% 1	840
	11th to 20th	Night	29% 14% 29% 23% 6%	691
	21st to end	Night	27% 14% 31% 22% 6%	630
May	1st to 10th	Night	30% 14% 28% 21% 7%	527
	11th to 20th	Night	22% 11% 32% 27% 8%	414
	21st to end	Night	28% 11% 28% 27% 6%	455
June	1st to 10th	Night	20% 7% 35% 32% 6%	420
	11th to 20th	Night	18% 10% 26% 33% 11% 1	420
	21st to end	Night	24% 8% 28% 31% 9% 1	420
July	1st to 10th	Night	22% 10% 27% 32% 9%	410
	11th to 20th	Night	15% 8% 26% 39% 12%	408
	21st to end	Night	20% 7% 25% 35% 12% 1	460
August	1st to 10th	Night	17% 7% 22% 36% 16% 1	418
	11th to 20th	Night	19% 9% 22% 33% 17% 1	574
	21st to end	Night	22% 8% 23% 31% 14% 2	761
September	1st to 10th	Night	23% 12% 24% 30% 11% 1	840
	11th to 20th	Night	23% 9% 27% 26% 13% 1	840
	21st to end	Night	24% 10% 26% 26% 10% 2	840
October	1st to 10th	Night	25% 13% 25% 26% 10% 1	840
	11th to 20th	Night	35% 14% 23% 19% 8% 1	813
	21st to end	Night	34% 16% 23% 20% 6% 1	880
November	1st to 10th	Night	35% 17% 23% 19% 6% 1	820
	11th to 20th	Night	28% 20% 24% 21% 7% 1	890
	21st to end	Night	30% 19% 26% 18% 5% 1	950
December	1st to 10th	Night	29% 13% 26% 23% 7% 1	950
	11th to 20th	Night	27% 18% 26% 21% 7% 1	950
	21st to end	Night	26% 18% 26% 22% 7% 1	1045

Page generated at 2026-10-11 05:06:27. Version ac07

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