Rouge Matawin
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rouge Matawin clear sky chart from 2005-11-06 to 2026-03-03.

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	15% 13% 4 11% 6% 5% 5% 4 5% 6% 26%	131140
	Night	14% 13% 5% 12% 7% 5% 5% 3 5% 6% 25%	130012
Transparency	Day	57% 5% 10% 18% 9% 1	134572
	Night	59% 5% 10% 16% 8% 1	134667
Seeing	Day	25% 17% 31% 18% 7% 2	15998
	Night	22% 15% 30% 23% 8% 1	25104

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	10% 16% 8% 19% 8% 6% 7% 3 3 4 14%	4661
	11th to 20th	Day	7% 19% 8% 21% 10% 6% 4 3 4 3 16%	4650
	21st to end	Day	5% 9% 7% 20% 8% 7% 6% 5% 6% 8% 19%	5124
February	1st to 10th	Day	8% 16% 6% 16% 10% 7% 4 3 4 6% 21%	1834
	11th to 20th	Day	9% 18% 6% 14% 7% 6% 5% 4 4 5% 22%	1901
	21st to end	Day	12% 18% 6% 12% 8% 6% 4 3 4 5% 22%	1730
March	1st to 10th	Day	13% 21% 5% 14% 7% 5% 4 2 4 4 20%	4496
	11th to 20th	Day	10% 16% 6% 12% 7% 5% 4 4 5% 5% 26%	4750
	21st to end	Day	12% 17% 5% 10% 5% 4 4 3 5% 5% 31%	5920
April	1st to 10th	Day	18% 18% 5% 9% 5% 3 4 3 4 5% 26%	2400
	11th to 20th	Day	21% 13% 4 7% 4 4 4 3 4 5% 32%	2374
	21st to end	Day	19% 14% 4 9% 5% 4 4 3 4 4 29%	2592
May	1st to 10th	Day	23% 13% 4 9% 5% 5% 5% 3 5% 5% 23%	6346
	11th to 20th	Day	21% 9% 3 8% 6% 5% 5% 4 5% 6% 29%	6318
	21st to end	Day	22% 11% 3 8% 5% 5% 4 3 5% 6% 28%	6949
June	1st to 10th	Day	23% 10% 3 8% 4 5% 5% 3 5% 7% 26%	2800
	11th to 20th	Day	16% 8% 3 8% 6% 5% 5% 4 7% 8% 31%	2800
	21st to end	Day	23% 9% 3 8% 6% 5% 5% 3 6% 7% 25%	2800
July	1st to 10th	Day	18% 8% 3 9% 6% 6% 6% 5% 7% 8% 25%	6360
	11th to 20th	Day	11% 7% 3 8% 5% 5% 6% 5% 7% 9% 34%	6360
	21st to end	Day	10% 6% 2 7% 5% 5% 6% 5% 7% 10% 39%	6926
August	1st to 10th	Day	14% 8% 3 8% 6% 6% 6% 5% 7% 9% 29%	4563
	11th to 20th	Day	16% 8% 3 8% 5% 5% 5% 4 6% 7% 33%	4217
	21st to end	Day	15% 7% 3 9% 5% 6% 5% 4 6% 8% 32%	4312
September	1st to 10th	Day	17% 7% 2 7% 4 4 5% 4 6% 8% 37%	2400
	11th to 20th	Day	15% 8% 2 7% 4 4 4 4 5% 7% 40%	2340
	21st to end	Day	21% 9% 3 5% 4 4 4 2 5% 6% 37%	2200
October	1st to 10th	Day	20% 12% 3 8% 5% 4 4 3 5% 6% 30%	2024
	11th to 20th	Day	22% 17% 3 9% 5% 4 5% 3 4 5% 24%	1961
	21st to end	Day	23% 17% 5% 9% 5% 5% 4 2 4 5% 21%	1980
November	1st to 10th	Day	15% 19% 6% 10% 5% 4 3 3 4 5% 27%	1851
	11th to 20th	Day	16% 18% 6% 13% 7% 5% 4 3 4 4 20%	1727
	21st to end	Day	17% 22% 6% 16% 7% 4 4 2 3 4 17%	1680
December	1st to 10th	Day	15% 19% 9% 17% 8% 6% 4 3 3 4 11%	2680
	11th to 20th	Day	15% 16% 7% 15% 9% 6% 4 3 5% 5% 16%	3066
	21st to end	Day	14% 18% 7% 14% 7% 5% 5% 3 4 4 18%	4048
January	1st to 10th	Night	9% 18% 9% 20% 8% 6% 5% 4 4 4 15%	8234
	11th to 20th	Night	7% 16% 8% 21% 14% 8% 5% 3 4 3 10%	8235
	21st to end	Night	4 10% 7% 19% 10% 8% 7% 4 7% 6% 18%	9057
February	1st to 10th	Night	8% 14% 6% 14% 8% 8% 6% 5% 4 6% 20%	2782
	11th to 20th	Night	8% 14% 7% 14% 9% 8% 5% 4 5% 4 21%	2604
	21st to end	Night	10% 14% 6% 11% 8% 6% 6% 3 5% 5% 25%	2076
March	1st to 10th	Night	17% 18% 5% 12% 7% 5% 5% 3 4 4 21%	5389
	11th to 20th	Night	11% 15% 5% 11% 6% 6% 5% 3 5% 6% 26%	5194
	21st to end	Night	13% 12% 6% 11% 6% 6% 5% 3 5% 5% 27%	5011
April	1st to 10th	Night	21% 13% 4 10% 5% 4 3 3 5% 4 28%	2000
	11th to 20th	Night	15% 12% 5% 7% 4 5% 4 2 5% 6% 35%	1975
	21st to end	Night	20% 12% 4 9% 4 2 3 3 5% 5% 33%	1823
May	1st to 10th	Night	19% 13% 4 8% 5% 5% 5% 4 5% 6% 26%	3594
	11th to 20th	Night	19% 10% 4 7% 4 4 4 3 5% 7% 31%	3575
	21st to end	Night	23% 9% 3 8% 5% 5% 5% 4 5% 6% 27%	3926
June	1st to 10th	Night	19% 10% 3 7% 5% 5% 5% 4 5% 7% 31%	1600
	11th to 20th	Night	16% 8% 4 5% 6% 4 4 4 5% 7% 37%	1600
	21st to end	Night	20% 8% 2 6% 5% 4 5% 5% 6% 7% 34%	1600
July	1st to 10th	Night	14% 8% 3 8% 6% 6% 6% 5% 8% 8% 28%	3600
	11th to 20th	Night	11% 8% 3 7% 5% 5% 5% 3 6% 8% 39%	3600
	21st to end	Night	10% 6% 2 6% 4 4 4 4 7% 8% 46%	3926
August	1st to 10th	Night	11% 8% 3 7% 5% 5% 5% 4 6% 7% 38%	2586
	11th to 20th	Night	16% 8% 4 8% 4 4 4 3 6% 6% 37%	2795
	21st to end	Night	18% 8% 3 7% 5% 4 4 4 6% 6% 34%	3586
September	1st to 10th	Night	14% 9% 2 6% 3 4 4 3 5% 7% 43%	2000
	11th to 20th	Night	15% 7% 2 5% 4 4 4 3 5% 7% 45%	2060
	21st to end	Night	16% 9% 3 7% 5% 3 4 3 5% 7% 39%	2200
October	1st to 10th	Night	16% 10% 3 7% 5% 5% 3 3 4 6% 39%	2374
	11th to 20th	Night	19% 15% 4 8% 5% 5% 4 3 5% 5% 27%	2437
	21st to end	Night	22% 16% 4 10% 5% 5% 4 3 5% 5% 21%	2860
November	1st to 10th	Night	16% 15% 6% 10% 5% 5% 5% 3 5% 6% 24%	2667
	11th to 20th	Night	14% 14% 6% 14% 7% 5% 5% 3 5% 5% 21%	2888
	21st to end	Night	17% 19% 7% 14% 7% 5% 4 3 4 4 15%	2940
December	1st to 10th	Night	13% 17% 7% 18% 10% 8% 5% 3 4 4 11%	4720
	11th to 20th	Night	18% 17% 6% 13% 9% 6% 4 2 3 3 18%	5348
	21st to end	Night	16% 20% 8% 12% 7% 4 3 3 4 6% 17%	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	72% 5% 6% 12% 4	4662
	11th to 20th	Day	72% 4 4 10% 9% 1	4680
	21st to end	Day	63% 4 6% 13% 13% 1	5124
February	1st to 10th	Day	65% 3 5% 16% 8% 2	1834
	11th to 20th	Day	64% 3 7% 14% 11% 1	1910
	21st to end	Day	66% 3 5% 14% 10% 2	1730
March	1st to 10th	Day	69% 2 5% 9% 11% 3	4499
	11th to 20th	Day	60% 4 12% 10% 12% 2	4750
	21st to end	Day	56% 3 7% 16% 17% 2	5920
April	1st to 10th	Day	61% 3 8% 15% 11% 2	2400
	11th to 20th	Day	56% 3 7% 20% 12% 2	2374
	21st to end	Day	59% 4 7% 15% 13% 3	2592
May	1st to 10th	Day	61% 4 7% 17% 9% 1	6357
	11th to 20th	Day	55% 5% 13% 19% 7% 2	6322
	21st to end	Day	57% 4 9% 16% 13% 1	6949
June	1st to 10th	Day	57% 5% 8% 18% 11% 1	2800
	11th to 20th	Day	51% 4 13% 20% 10% 2	2800
	21st to end	Day	58% 4 13% 17% 8% 1	2800
July	1st to 10th	Day	52% 8% 12% 22% 5%	6290
	11th to 20th	Day	41% 7% 19% 27% 5%	6285
	21st to end	Day	39% 7% 17% 28% 9%	6728
August	1st to 10th	Day	50% 6% 16% 21% 6%	4549
	11th to 20th	Day	47% 7% 17% 24% 5%	4259
	21st to end	Day	46% 7% 13% 21% 12% 1	4312
September	1st to 10th	Day	43% 5% 16% 26% 10% 1	2400
	11th to 20th	Day	44% 4 14% 29% 9% 1	2340
	21st to end	Day	49% 4 12% 25% 10%	2200
October	1st to 10th	Day	53% 6% 11% 24% 6%	3297
	11th to 20th	Day	57% 4 11% 21% 6%	3177
	21st to end	Day	58% 6% 17% 13% 5% 1	3180
November	1st to 10th	Day	60% 3 11% 18% 7%	1851
	11th to 20th	Day	68% 4 8% 12% 8% 1	1727
	21st to end	Day	72% 4 7% 11% 6% 1	1680
December	1st to 10th	Day	78% 4 5% 11% 4	2680
	11th to 20th	Day	68% 5% 5% 16% 6%	3066
	21st to end	Day	68% 4 5% 14% 8%	4048
January	1st to 10th	Night	73% 4 8% 11% 3	8234
	11th to 20th	Night	77% 5% 6% 8% 4 1	8280
	21st to end	Night	65% 4 6% 12% 12% 1	9057
February	1st to 10th	Night	63% 5% 6% 17% 8% 1	2782
	11th to 20th	Night	64% 5% 7% 15% 8% 1	2606
	21st to end	Night	59% 4 6% 18% 11% 1	2076
March	1st to 10th	Night	68% 3 7% 9% 10% 2	5399
	11th to 20th	Night	58% 5% 11% 14% 10% 3	5195
	21st to end	Night	58% 4 7% 19% 9% 3	5011
April	1st to 10th	Night	59% 3 8% 16% 12% 2	2000
	11th to 20th	Night	50% 4 9% 22% 12% 2	1975
	21st to end	Night	54% 4 8% 21% 12% 2	1823
May	1st to 10th	Night	58% 4 12% 17% 9% 1	3600
	11th to 20th	Night	52% 6% 14% 16% 10% 1	3576
	21st to end	Night	57% 5% 11% 17% 10% 1	3927
June	1st to 10th	Night	52% 5% 12% 21% 11%	1600
	11th to 20th	Night	47% 4 13% 22% 11% 3	1600
	21st to end	Night	48% 6% 14% 20% 12% 1	1600
July	1st to 10th	Night	49% 8% 18% 19% 5%	3560
	11th to 20th	Night	41% 7% 20% 27% 4	3552
	21st to end	Night	35% 6% 19% 30% 9%	3809
August	1st to 10th	Night	44% 7% 19% 23% 7%	2576
	11th to 20th	Night	47% 5% 20% 22% 6%	2819
	21st to end	Night	47% 6% 15% 22% 9% 1	3586
September	1st to 10th	Night	40% 5% 17% 27% 11%	2000
	11th to 20th	Night	40% 5% 16% 30% 9% 1	2060
	21st to end	Night	44% 5% 13% 27% 10%	2200
October	1st to 10th	Night	46% 6% 15% 22% 11%	3881
	11th to 20th	Night	55% 4 13% 20% 8%	3960
	21st to end	Night	56% 4 15% 15% 8% 2	4610
November	1st to 10th	Night	59% 5% 11% 18% 5% 1	2667
	11th to 20th	Night	64% 4 9% 14% 7% 2	2888
	21st to end	Night	71% 5% 7% 13% 4	2940
December	1st to 10th	Night	76% 5% 8% 8% 3	4720
	11th to 20th	Night	71% 4 4 13% 7%	5348
	21st to end	Night	69% 3 5% 11% 11% 1	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	23% 22% 39% 15% 2	220
	11th to 20th	Day	26% 19% 35% 14% 5% 1	220
	21st to end	Day	18% 20% 35% 21% 6%	242
February	1st to 10th	Day	26% 27% 34% 10% 2 1	302
	11th to 20th	Day	25% 25% 38% 11% 1	388
	21st to end	Day	27% 24% 34% 12% 2	446
March	1st to 10th	Day	26% 21% 35% 15% 3	508
	11th to 20th	Day	25% 24% 34% 13% 3 1	500
	21st to end	Day	28% 22% 30% 14% 5% 1	550
April	1st to 10th	Day	31% 19% 29% 15% 5% 1	500
	11th to 20th	Day	35% 17% 25% 12% 9% 2	492
	21st to end	Day	31% 20% 30% 14% 4 1	500
May	1st to 10th	Day	30% 17% 32% 15% 4 1	503
	11th to 20th	Day	27% 15% 31% 20% 6% 1	527
	21st to end	Day	27% 18% 30% 19% 6% 1	573
June	1st to 10th	Day	27% 15% 34% 18% 5% 1	530
	11th to 20th	Day	21% 19% 30% 18% 9% 2	530
	21st to end	Day	27% 15% 30% 21% 5% 2	530
July	1st to 10th	Day	18% 12% 37% 24% 7% 2	525
	11th to 20th	Day	16% 11% 38% 28% 5% 2	524
	21st to end	Day	15% 13% 34% 27% 11% 2	576
August	1st to 10th	Day	16% 12% 30% 28% 12% 2	526
	11th to 20th	Day	16% 8% 30% 27% 14% 5%	519
	21st to end	Day	21% 12% 30% 20% 12% 5%	583
September	1st to 10th	Day	18% 15% 31% 21% 10% 5%	530
	11th to 20th	Day	16% 12% 25% 24% 15% 8%	530
	21st to end	Day	22% 15% 23% 22% 12% 5%	530
October	1st to 10th	Day	25% 16% 29% 17% 9% 5%	530
	11th to 20th	Day	28% 21% 26% 17% 6% 3	508
	21st to end	Day	33% 16% 28% 17% 4	462
November	1st to 10th	Day	31% 20% 29% 15% 4	425
	11th to 20th	Day	29% 21% 32% 14% 4	267
	21st to end	Day	33% 25% 30% 7% 4 1	220
December	1st to 10th	Day	26% 19% 33% 13% 8%	220
	11th to 20th	Day	31% 23% 33% 10% 2	220
	21st to end	Day	31% 20% 32% 11% 4 2	242
January	1st to 10th	Night	22% 20% 38% 15% 5%	840
	11th to 20th	Night	21% 19% 35% 19% 6%	840
	21st to end	Night	15% 18% 39% 22% 7%	924
February	1st to 10th	Night	16% 21% 36% 21% 6%	840
	11th to 20th	Night	18% 22% 38% 17% 4	823
	21st to end	Night	20% 18% 36% 22% 4	692
March	1st to 10th	Night	26% 18% 32% 20% 4	809
	11th to 20th	Night	24% 19% 33% 19% 5% 1	800
	21st to end	Night	21% 18% 32% 23% 6% 1	880
April	1st to 10th	Night	29% 14% 28% 23% 5% 1	800
	11th to 20th	Night	25% 16% 28% 22% 9%	791
	21st to end	Night	30% 14% 28% 22% 6%	623
May	1st to 10th	Night	25% 9% 29% 26% 10% 1	400
	11th to 20th	Night	23% 8% 32% 29% 8%	394
	21st to end	Night	22% 10% 38% 22% 8%	433
June	1st to 10th	Night	22% 9% 32% 30% 6% 1	400
	11th to 20th	Night	21% 9% 26% 30% 13% 1	400
	21st to end	Night	22% 8% 21% 36% 14% 1	400
July	1st to 10th	Night	13% 7% 32% 37% 10% 1	390
	11th to 20th	Night	13% 7% 28% 38% 13% 2	388
	21st to end	Night	11% 6% 29% 40% 13% 1	438
August	1st to 10th	Night	13% 6% 20% 45% 16% 1	398
	11th to 20th	Night	15% 5% 23% 35% 21% 2	537
	21st to end	Night	20% 8% 27% 28% 15% 3	880
September	1st to 10th	Night	18% 8% 28% 32% 12% 1	800
	11th to 20th	Night	19% 6% 25% 28% 19% 2	800
	21st to end	Night	21% 10% 27% 25% 16% 2	800
October	1st to 10th	Night	22% 13% 28% 24% 12% 1	800
	11th to 20th	Night	28% 15% 28% 19% 9% 1	800
	21st to end	Night	29% 16% 26% 23% 5%	880
November	1st to 10th	Night	27% 19% 29% 19% 5% 1	820
	11th to 20th	Night	24% 18% 32% 17% 8% 1	840
	21st to end	Night	28% 20% 28% 17% 5% 1	840
December	1st to 10th	Night	26% 19% 32% 18% 5% 1	840
	11th to 20th	Night	26% 19% 33% 16% 5% 1	840
	21st to end	Night	30% 20% 28% 17% 4	924

Page generated at 2026-02-28 01:40:21. Version ac07

Copyright © 2026 Attilla Danko.