Moosonee / Moose Factory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Moosonee / Moose Factory clear sky chart from 2005-11-06 to 2025-10-04.

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 10% 6% 5% 5% 4 5% 6% 26%	127166
	Night	14% 15% 5% 12% 7% 6% 6% 4 5% 5% 22%	122425
Transparency	Day	58% 6% 11% 18% 7%	130529
	Night	63% 5% 10% 15% 5%	127150
Seeing	Day	20% 7% 26% 30% 14% 3	16625
	Night	21% 7% 26% 32% 13% 2	25474

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	6% 22% 11% 20% 8% 8% 8% 4 4 3 6%	3158
	11th to 20th	Day	7% 16% 10% 21% 10% 10% 7% 5% 5% 3 5%	3133
	21st to end	Day	8% 15% 6% 13% 7% 7% 9% 7% 8% 6% 14%	3678
February	1st to 10th	Day	7% 15% 6% 13% 9% 8% 8% 6% 7% 6% 15%	1735
	11th to 20th	Day	9% 17% 5% 12% 9% 7% 7% 7% 7% 6% 15%	1753
	21st to end	Day	8% 13% 5% 12% 7% 8% 9% 5% 6% 7% 20%	1485
March	1st to 10th	Day	13% 15% 5% 12% 7% 7% 6% 5% 6% 5% 20%	4669
	11th to 20th	Day	12% 16% 6% 17% 7% 5% 5% 4 4 5% 18%	4980
	21st to end	Day	11% 15% 5% 12% 7% 9% 7% 4 4 4 22%	5465
April	1st to 10th	Day	15% 15% 6% 11% 6% 5% 4 3 4 4 26%	2468
	11th to 20th	Day	16% 13% 5% 9% 5% 4 4 3 5% 6% 30%	2572
	21st to end	Day	15% 14% 5% 9% 6% 4 3 3 3 5% 34%	2600
May	1st to 10th	Day	15% 11% 3 10% 4 5% 4 3 4 5% 36%	6346
	11th to 20th	Day	17% 14% 4 10% 5% 4 3 3 4 5% 30%	6625
	21st to end	Day	17% 15% 3 7% 4 3 3 3 5% 7% 34%	7451
June	1st to 10th	Day	19% 10% 3 8% 4 4 4 3 5% 7% 34%	3000
	11th to 20th	Day	13% 8% 3 8% 5% 5% 4 4 6% 6% 39%	3000
	21st to end	Day	17% 7% 3 7% 6% 5% 4 3 6% 7% 36%	3000
July	1st to 10th	Day	18% 9% 3 7% 5% 4 4 3 4 7% 36%	6819
	11th to 20th	Day	18% 7% 3 7% 6% 6% 5% 4 6% 9% 28%	6820
	21st to end	Day	13% 7% 3 8% 5% 5% 5% 4 6% 9% 34%	7428
August	1st to 10th	Day	17% 9% 3 7% 4 4 5% 4 6% 8% 32%	4573
	11th to 20th	Day	16% 8% 3 6% 4 4 4 3 6% 8% 39%	4174
	21st to end	Day	15% 7% 3 8% 4 4 4 4 5% 8% 39%	4675
September	1st to 10th	Day	20% 9% 3 8% 5% 5% 5% 4 5% 6% 31%	2450
	11th to 20th	Day	22% 10% 4 8% 6% 5% 4 3 5% 7% 25%	2270
	21st to end	Day	24% 11% 4 6% 5% 4 4 3 5% 5% 30%	2177
October	1st to 10th	Day	25% 16% 3 8% 4 4 3 4 4 5% 25%	1930
	11th to 20th	Day	24% 19% 4 10% 5% 4 4 3 4 6% 17%	1900
	21st to end	Day	23% 20% 5% 12% 6% 4 4 3 4 4 15%	1809
November	1st to 10th	Day	22% 25% 7% 10% 5% 4 3 2 4 4 14%	1566
	11th to 20th	Day	25% 21% 7% 12% 6% 4 3 3 4 4 13%	1600
	21st to end	Day	19% 24% 8% 13% 5% 6% 5% 2 2 3 13%	1480
December	1st to 10th	Day	8% 21% 9% 17% 9% 8% 6% 4 4 4 10%	2280
	11th to 20th	Day	11% 18% 6% 12% 12% 6% 5% 5% 5% 5% 16%	2621
	21st to end	Day	14% 18% 7% 16% 9% 6% 4 4 6% 5% 10%	3476
January	1st to 10th	Night	6% 22% 11% 20% 8% 7% 6% 4 4 3 8%	6808
	11th to 20th	Night	7% 18% 8% 21% 10% 9% 8% 6% 5% 2 5%	6772
	21st to end	Night	8% 15% 6% 13% 8% 9% 9% 7% 7% 5% 14%	7300
February	1st to 10th	Night	7% 12% 5% 12% 10% 10% 10% 7% 6% 5% 15%	2664
	11th to 20th	Night	8% 17% 5% 13% 10% 8% 9% 6% 8% 3 13%	2533
	21st to end	Night	6% 14% 5% 13% 8% 7% 11% 7% 6% 6% 17%	2145
March	1st to 10th	Night	13% 16% 5% 12% 7% 6% 7% 5% 5% 4 20%	5155
	11th to 20th	Night	14% 17% 6% 16% 9% 7% 6% 4 4 4 12%	4979
	21st to end	Night	10% 11% 5% 14% 8% 11% 6% 3 4 5% 22%	5467
April	1st to 10th	Night	18% 13% 4 10% 5% 4 6% 3 5% 6% 26%	1950
	11th to 20th	Night	12% 14% 5% 10% 5% 5% 4 3 5% 6% 31%	1777
	21st to end	Night	15% 14% 4 9% 6% 4 4 3 5% 5% 32%	1800
May	1st to 10th	Night	19% 11% 4 9% 4 3 3 2 4 4 37%	3594
	11th to 20th	Night	18% 12% 5% 9% 4 4 3 3 4 6% 31%	3281
	21st to end	Night	18% 10% 3 6% 4 3 4 3 5% 6% 39%	3447
June	1st to 10th	Night	18% 9% 2 8% 5% 3 4 4 4 7% 37%	1400
	11th to 20th	Night	13% 8% 3 8% 5% 4 4 4 6% 8% 37%	1400
	21st to end	Night	15% 7% 2 7% 6% 5% 5% 3 6% 8% 37%	1400
July	1st to 10th	Night	17% 9% 3 6% 4 4 5% 4 6% 8% 34%	3160
	11th to 20th	Night	16% 9% 3 7% 5% 5% 5% 4 7% 8% 32%	3160
	21st to end	Night	14% 7% 2 7% 4 5% 5% 4 6% 7% 39%	3446
August	1st to 10th	Night	16% 10% 3 7% 4 5% 5% 4 6% 7% 32%	2576
	11th to 20th	Night	16% 7% 2 5% 3 4 4 4 6% 8% 39%	2875
	21st to end	Night	12% 7% 3 7% 4 4 4 4 5% 8% 43%	3223
September	1st to 10th	Night	21% 9% 3 6% 3 4 4 4 4 7% 34%	1930
	11th to 20th	Night	21% 11% 3 7% 4 4 4 4 4 7% 30%	2128
	21st to end	Night	20% 11% 3 6% 4 4 4 3 4 6% 35%	2223
October	1st to 10th	Night	22% 10% 3 8% 4 5% 4 3 5% 6% 29%	2317
	11th to 20th	Night	23% 16% 4 10% 6% 5% 4 4 4 5% 18%	2280
	21st to end	Night	20% 18% 5% 12% 6% 5% 4 3 4 4 18%	2786
November	1st to 10th	Night	20% 21% 7% 12% 5% 5% 4 2 4 5% 16%	2732
	11th to 20th	Night	21% 24% 7% 10% 5% 4 4 3 4 4 15%	2800
	21st to end	Night	21% 23% 8% 13% 8% 4 3 3 3 3 9%	2919
December	1st to 10th	Night	10% 23% 9% 15% 7% 8% 5% 3 4 4 12%	4910
	11th to 20th	Night	10% 18% 6% 14% 10% 7% 6% 4 4 4 15%	5586
	21st to end	Night	14% 20% 7% 15% 8% 6% 5% 3 4 5% 12%	7502

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	83% 3 6% 5% 2 1	3159
	11th to 20th	Day	81% 4 7% 6% 2	3160
	21st to end	Day	66% 5% 8% 15% 6%	3678
February	1st to 10th	Day	66% 5% 7% 17% 5%	1735
	11th to 20th	Day	65% 7% 12% 12% 4	1762
	21st to end	Day	63% 7% 11% 14% 6%	1485
March	1st to 10th	Day	63% 5% 7% 16% 9%	4672
	11th to 20th	Day	66% 6% 8% 14% 6%	4980
	21st to end	Day	63% 7% 7% 16% 7%	5465
April	1st to 10th	Day	61% 5% 8% 15% 10% 1	2468
	11th to 20th	Day	55% 6% 9% 18% 11% 1	2572
	21st to end	Day	53% 6% 9% 19% 12% 2	2600
May	1st to 10th	Day	50% 6% 8% 20% 16% 1	6357
	11th to 20th	Day	55% 6% 10% 17% 10% 1	6629
	21st to end	Day	48% 7% 11% 18% 14% 3	7451
June	1st to 10th	Day	50% 6% 10% 22% 12% 1	3000
	11th to 20th	Day	44% 6% 11% 23% 14% 2	3000
	21st to end	Day	46% 7% 13% 22% 11% 1	3000
July	1st to 10th	Day	49% 4 12% 28% 8%	6746
	11th to 20th	Day	51% 5% 17% 21% 5%	6739
	21st to end	Day	46% 6% 20% 25% 3	7216
August	1st to 10th	Day	49% 7% 15% 24% 5%	4557
	11th to 20th	Day	45% 6% 17% 27% 5%	4213
	21st to end	Day	43% 6% 16% 30% 6%	4674
September	1st to 10th	Day	52% 8% 17% 19% 5%	2450
	11th to 20th	Day	58% 8% 16% 16% 2	2270
	21st to end	Day	56% 6% 12% 19% 6%	2177
October	1st to 10th	Day	62% 5% 14% 16% 4	3190
	11th to 20th	Day	70% 4 13% 11% 2	3140
	21st to end	Day	75% 5% 7% 10% 4	2961
November	1st to 10th	Day	74% 6% 8% 9% 2	1566
	11th to 20th	Day	76% 5% 9% 9% 1	1600
	21st to end	Day	78% 6% 7% 9% 1	1480
December	1st to 10th	Day	77% 4 8% 10% 1	2280
	11th to 20th	Day	69% 5% 12% 13% 1	2621
	21st to end	Day	74% 6% 8% 12% 1	3476
January	1st to 10th	Night	81% 5% 7% 5% 1	6808
	11th to 20th	Night	84% 4 6% 5% 1	6820
	21st to end	Night	69% 5% 10% 14% 2	7300
February	1st to 10th	Night	67% 5% 8% 14% 6%	2664
	11th to 20th	Night	69% 7% 10% 10% 4	2535
	21st to end	Night	64% 6% 11% 14% 5%	2145
March	1st to 10th	Night	67% 5% 6% 11% 9% 2	5165
	11th to 20th	Night	74% 4 7% 10% 4	4980
	21st to end	Night	63% 5% 6% 17% 9%	5467
April	1st to 10th	Night	59% 5% 7% 18% 10% 1	1950
	11th to 20th	Night	54% 6% 8% 20% 12% 1	1777
	21st to end	Night	54% 5% 7% 17% 15% 1	1800
May	1st to 10th	Night	51% 5% 6% 22% 14% 2	3600
	11th to 20th	Night	54% 5% 10% 18% 12% 1	3282
	21st to end	Night	46% 6% 11% 17% 17% 3	3448
June	1st to 10th	Night	48% 6% 10% 23% 11% 2	1400
	11th to 20th	Night	44% 7% 11% 22% 15% 1	1400
	21st to end	Night	46% 7% 14% 20% 11% 2	1400
July	1st to 10th	Night	49% 5% 13% 29% 5%	3125
	11th to 20th	Night	49% 5% 19% 18% 7% 2	3118
	21st to end	Night	44% 6% 18% 25% 7%	3344
August	1st to 10th	Night	50% 8% 15% 24% 3	2568
	11th to 20th	Night	42% 7% 21% 26% 4	2902
	21st to end	Night	39% 5% 16% 30% 10%	3223
September	1st to 10th	Night	50% 7% 17% 20% 5%	1930
	11th to 20th	Night	52% 8% 18% 19% 4	2128
	21st to end	Night	51% 7% 13% 21% 8%	2223
October	1st to 10th	Night	57% 5% 11% 22% 5%	3837
	11th to 20th	Night	64% 5% 13% 16% 2	3779
	21st to end	Night	66% 5% 11% 15% 2	4584
November	1st to 10th	Night	73% 6% 11% 9% 2	2732
	11th to 20th	Night	73% 6% 10% 9% 2	2800
	21st to end	Night	80% 6% 8% 6% 1	2919
December	1st to 10th	Night	76% 4 8% 11% 1	4910
	11th to 20th	Night	72% 5% 10% 10% 2	5585
	21st to end	Night	74% 5% 8% 12% 1	7502

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	16% 9% 34% 26% 15% 2	200
	11th to 20th	Day	13% 9% 29% 33% 16% 2	200
	21st to end	Day	15% 5% 24% 33% 18% 5%	263
February	1st to 10th	Day	10% 14% 28% 29% 16% 2	300
	11th to 20th	Day	13% 10% 33% 31% 13% 1	300
	21st to end	Day	17% 10% 31% 34% 8% 1	249
March	1st to 10th	Day	15% 11% 31% 29% 12% 3	390
	11th to 20th	Day	14% 9% 28% 32% 12% 5%	500
	21st to end	Day	15% 8% 33% 34% 9% 1	550
April	1st to 10th	Day	15% 7% 27% 31% 15% 4	500
	11th to 20th	Day	20% 8% 23% 32% 13% 4	492
	21st to end	Day	22% 8% 22% 28% 15% 5%	500
May	1st to 10th	Day	19% 9% 23% 31% 14% 5%	503
	11th to 20th	Day	22% 7% 29% 26% 13% 3	652
	21st to end	Day	20% 5% 26% 32% 15% 2	789
June	1st to 10th	Day	21% 5% 26% 35% 12% 2	730
	11th to 20th	Day	16% 6% 29% 35% 12% 3	730
	21st to end	Day	20% 6% 23% 31% 17% 4	730
July	1st to 10th	Day	20% 5% 23% 32% 16% 3	721
	11th to 20th	Day	18% 4 23% 35% 16% 3	718
	21st to end	Day	19% 7% 20% 35% 15% 4	794
August	1st to 10th	Day	22% 6% 19% 30% 19% 5%	616
	11th to 20th	Day	19% 7% 18% 24% 26% 5%	519
	21st to end	Day	23% 6% 20% 27% 17% 6%	583
September	1st to 10th	Day	20% 7% 27% 28% 16% 1	530
	11th to 20th	Day	24% 6% 24% 31% 12% 3	530
	21st to end	Day	26% 9% 24% 24% 13% 3	530
October	1st to 10th	Day	27% 11% 26% 23% 11% 2	502
	11th to 20th	Day	34% 8% 20% 29% 7% 2	490
	21st to end	Day	29% 7% 28% 27% 10% 1	294
November	1st to 10th	Day	29% 12% 36% 19% 4	200
	11th to 20th	Day	30% 6% 33% 20% 10% 2	200
	21st to end	Day	28% 11% 33% 22% 6% 3	200
December	1st to 10th	Day	20% 10% 27% 23% 17% 5%	200
	11th to 20th	Day	12% 15% 29% 29% 16% 1	200
	21st to end	Day	16% 10% 36% 24% 11% 3	220
January	1st to 10th	Night	20% 6% 29% 31% 12% 2	1000
	11th to 20th	Night	17% 7% 28% 33% 13% 2	1000
	21st to end	Night	14% 4 22% 36% 21% 3	1100
February	1st to 10th	Night	12% 5% 26% 39% 16% 2	864
	11th to 20th	Night	17% 4 26% 36% 16% 1	783
	21st to end	Night	13% 6% 25% 36% 18% 2	660
March	1st to 10th	Night	15% 7% 29% 34% 15% 2	800
	11th to 20th	Night	17% 8% 31% 31% 12% 1	800
	21st to end	Night	15% 6% 29% 37% 13% 1	880
April	1st to 10th	Night	23% 7% 25% 31% 13% 1	725
	11th to 20th	Night	18% 5% 23% 38% 14% 2	593
	21st to end	Night	21% 6% 27% 32% 11% 3	600
May	1st to 10th	Night	21% 5% 27% 31% 15% 2	400
	11th to 20th	Night	22% 9% 26% 31% 10% 2	394
	21st to end	Night	20% 7% 24% 36% 12% 1	433
June	1st to 10th	Night	19% 6% 24% 36% 13% 2	400
	11th to 20th	Night	14% 5% 25% 38% 18% 1	400
	21st to end	Night	17% 4 22% 39% 18% 1	400
July	1st to 10th	Night	20% 4 20% 38% 16% 2	390
	11th to 20th	Night	17% 4 21% 44% 15% 1	388
	21st to end	Night	18% 4 14% 42% 20% 3	438
August	1st to 10th	Night	22% 4 15% 33% 25% 2	474
	11th to 20th	Night	20% 4 22% 35% 18% 2	594
	21st to end	Night	20% 4 20% 36% 18% 2	660
September	1st to 10th	Night	26% 7% 23% 31% 13% 1	730
	11th to 20th	Night	27% 6% 25% 30% 12% 1	800
	21st to end	Night	25% 6% 26% 29% 12% 2	800
October	1st to 10th	Night	27% 8% 29% 25% 9% 1	773
	11th to 20th	Night	30% 8% 29% 22% 8% 3	760
	21st to end	Night	28% 9% 26% 26% 9% 1	836
November	1st to 10th	Night	27% 11% 33% 21% 7% 1	780
	11th to 20th	Night	31% 11% 28% 22% 7% 1	800
	21st to end	Night	30% 10% 31% 21% 7% 1	919
December	1st to 10th	Night	21% 11% 30% 27% 11% 2	1000
	11th to 20th	Night	18% 10% 28% 29% 14% 2	1000
	21st to end	Night	20% 7% 27% 31% 10% 4	1100

Page generated at 2025-10-01 01:39:04. Version ac07

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