Muskoka District Municipality
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Muskoka District Municipality clear sky chart from 2005-11-06 to 2025-02-25.

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	17% 12% 4 8% 5% 4 4 3 5% 6% 31%	109165
	Night	17% 14% 5% 10% 5% 4 4 3 4 5% 29%	109447
Transparency	Day	54% 5% 10% 20% 10% 1	112789
	Night	57% 5% 10% 18% 10% 1	113988
Seeing	Day	24% 15% 30% 20% 8% 3	15208
	Night	24% 12% 29% 24% 9% 1	24249

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% 18% 10% 11% 4 6% 4 2 4 4 25%	3315
	11th to 20th	Day	10% 21% 10% 17% 8% 6% 5% 3 4 2 13%	3732
	21st to end	Day	13% 20% 8% 16% 6% 6% 4 3 3 4 16%	4466
February	1st to 10th	Day	13% 20% 7% 16% 7% 5% 3 2 4 3 19%	1800
	11th to 20th	Day	14% 16% 6% 14% 5% 5% 3 3 4 6% 23%	1753
	21st to end	Day	17% 19% 6% 12% 6% 5% 4 3 4 5% 20%	1465
March	1st to 10th	Day	19% 16% 5% 8% 4 4 4 3 4 5% 27%	3432
	11th to 20th	Day	11% 18% 7% 10% 6% 5% 4 3 4 6% 26%	3480
	21st to end	Day	14% 13% 6% 7% 4 4 3 3 4 5% 37%	3815
April	1st to 10th	Day	21% 14% 4 8% 4 4 4 3 4 6% 28%	2256
	11th to 20th	Day	23% 11% 3 6% 4 4 4 4 3 4 35%	2356
	21st to end	Day	23% 12% 4 6% 4 4 3 3 4 4 33%	2470
May	1st to 10th	Day	21% 8% 2 6% 5% 4 5% 4 5% 6% 32%	4191
	11th to 20th	Day	16% 8% 2 6% 5% 4 4 4 6% 8% 37%	4398
	21st to end	Day	19% 6% 2 6% 4 4 4 4 5% 6% 42%	4837
June	1st to 10th	Day	20% 8% 2 6% 4 4 5% 4 6% 7% 34%	2660
	11th to 20th	Day	15% 6% 3 6% 5% 5% 5% 4 7% 7% 37%	2850
	21st to end	Day	20% 7% 3 6% 4 4 4 3 6% 7% 34%	2850
July	1st to 10th	Day	16% 6% 3 7% 5% 5% 5% 4 6% 9% 35%	4760
	11th to 20th	Day	15% 6% 2 6% 4 4 5% 4 5% 8% 42%	4517
	21st to end	Day	11% 6% 2 5% 4 4 4 4 6% 8% 47%	4641
August	1st to 10th	Day	15% 7% 3 7% 5% 5% 5% 4 5% 9% 35%	4104
	11th to 20th	Day	18% 7% 2 6% 4 5% 5% 4 6% 8% 35%	4044
	21st to end	Day	10% 5% 2 6% 4 4 5% 5% 6% 9% 44%	4386
September	1st to 10th	Day	16% 7% 2 5% 4 5% 5% 4 5% 8% 40%	2280
	11th to 20th	Day	16% 6% 2 6% 4 4 3 3 5% 7% 43%	2181
	21st to end	Day	20% 9% 2 6% 4 4 5% 4 4 6% 35%	2043
October	1st to 10th	Day	22% 8% 2 7% 5% 5% 4 4 5% 6% 33%	1900
	11th to 20th	Day	27% 12% 3 8% 5% 5% 4 3 5% 6% 23%	1900
	21st to end	Day	32% 12% 3 7% 4 3 5% 3 4 5% 21%	2090
November	1st to 10th	Day	20% 14% 4 7% 5% 4 4 4 5% 6% 27%	1606
	11th to 20th	Day	18% 18% 5% 10% 6% 5% 5% 4 4 4 22%	1600
	21st to end	Day	22% 22% 5% 9% 5% 5% 4 4 4 5% 16%	1600
December	1st to 10th	Day	18% 26% 7% 10% 5% 4 4 3 5% 4 14%	2600
	11th to 20th	Day	21% 24% 6% 13% 4 3 3 2 3 3 19%	2986
	21st to end	Day	24% 20% 6% 14% 4 3 3 2 3 4 17%	3801
January	1st to 10th	Night	14% 19% 9% 12% 6% 5% 4 3 4 5% 18%	6604
	11th to 20th	Night	11% 18% 8% 21% 8% 6% 5% 4 4 4 12%	6150
	21st to end	Night	13% 20% 10% 14% 6% 7% 4 2 4 4 16%	6490
February	1st to 10th	Night	13% 18% 6% 14% 7% 5% 5% 3 4 5% 20%	2600
	11th to 20th	Night	13% 17% 7% 14% 5% 5% 4 3 4 5% 24%	2533
	21st to end	Night	15% 19% 6% 11% 6% 5% 4 3 4 4 23%	2081
March	1st to 10th	Night	16% 13% 5% 10% 5% 4 4 3 5% 5% 30%	3408
	11th to 20th	Night	12% 18% 8% 9% 5% 3 4 3 5% 5% 29%	3479
	21st to end	Night	15% 10% 5% 7% 5% 4 4 4 5% 6% 36%	3817
April	1st to 10th	Night	22% 14% 4 6% 4 4 4 4 5% 6% 29%	1923
	11th to 20th	Night	19% 11% 3 7% 4 3 4 3 5% 5% 36%	1791
	21st to end	Night	21% 10% 3 7% 6% 5% 3 4 5% 6% 31%	1710
May	1st to 10th	Night	17% 7% 3 6% 4 4 5% 4 6% 6% 39%	2748
	11th to 20th	Night	16% 8% 3 5% 4 4 4 4 5% 7% 40%	2495
	21st to end	Night	12% 7% 2 6% 4 4 4 4 5% 9% 43%	2738
June	1st to 10th	Night	16% 9% 2 7% 4 5% 3 4 5% 8% 36%	1515
	11th to 20th	Night	13% 7% 2 5% 3 3 5% 4 7% 8% 44%	1330
	21st to end	Night	16% 8% 3 5% 5% 4 4 4 6% 6% 38%	1330
July	1st to 10th	Night	11% 6% 2 9% 5% 4 3 3 4 7% 44%	2210
	11th to 20th	Night	17% 5% 2 5% 4 3 3 3 5% 6% 47%	2443
	21st to end	Night	11% 5% 2 5% 3 4 4 3 5% 7% 51%	2895
August	1st to 10th	Night	12% 6% 2 6% 4 4 4 4 6% 8% 45%	2825
	11th to 20th	Night	17% 7% 2 5% 3 4 4 3 4 6% 45%	2785
	21st to end	Night	16% 5% 2 5% 3 3 3 3 5% 7% 50%	3238
September	1st to 10th	Night	12% 6% 2 6% 4 4 4 4 6% 7% 46%	1900
	11th to 20th	Night	14% 6% 1 6% 3 2 3 3 5% 8% 49%	1995
	21st to end	Night	19% 7% 2 7% 4 4 4 3 4 5% 42%	2135
October	1st to 10th	Night	20% 8% 2 6% 4 5% 4 3 5% 6% 36%	2280
	11th to 20th	Night	25% 11% 3 8% 4 4 4 4 4 6% 27%	2280
	21st to end	Night	27% 14% 5% 7% 4 5% 3 3 4 4 23%	2508
November	1st to 10th	Night	22% 14% 3 6% 4 3 4 3 5% 5% 30%	2689
	11th to 20th	Night	19% 17% 4 7% 4 5% 4 3 5% 5% 26%	2800
	21st to end	Night	23% 20% 6% 8% 5% 4 4 3 4 6% 17%	2800
December	1st to 10th	Night	21% 24% 7% 11% 4 4 3 3 4 5% 14%	4580
	11th to 20th	Night	17% 24% 7% 16% 5% 4 3 2 3 4 13%	5208
	21st to end	Night	24% 21% 7% 14% 4 4 3 2 3 4 15%	7134

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	64% 3 6% 18% 8%	3316
	11th to 20th	Day	79% 3 5% 8% 5% 1	3763
	21st to end	Day	74% 3 6% 9% 8% 1	4466
February	1st to 10th	Day	71% 3 6% 14% 5% 1	1800
	11th to 20th	Day	64% 4 9% 13% 9% 2	1762
	21st to end	Day	68% 4 7% 13% 7%	1465
March	1st to 10th	Day	59% 6% 12% 11% 11% 1	3435
	11th to 20th	Day	60% 5% 10% 16% 8% 1	3480
	21st to end	Day	49% 4 9% 22% 15% 2	3815
April	1st to 10th	Day	58% 4 9% 17% 11% 2	2256
	11th to 20th	Day	53% 5% 6% 22% 13% 1	2356
	21st to end	Day	55% 4 7% 18% 12% 3	2470
May	1st to 10th	Day	52% 6% 8% 21% 12% 2	4203
	11th to 20th	Day	43% 8% 11% 27% 10% 1	4402
	21st to end	Day	43% 6% 12% 20% 16% 3	4837
June	1st to 10th	Day	50% 5% 9% 22% 13% 1	2660
	11th to 20th	Day	44% 7% 10% 22% 15% 1	2850
	21st to end	Day	48% 6% 13% 21% 11% 1	2850
July	1st to 10th	Day	45% 6% 15% 23% 10% 1	4686
	11th to 20th	Day	40% 5% 14% 30% 10%	4439
	21st to end	Day	35% 6% 10% 32% 16%	4493
August	1st to 10th	Day	45% 7% 13% 25% 9% 1	4091
	11th to 20th	Day	45% 6% 15% 25% 8%	4083
	21st to end	Day	36% 7% 12% 35% 10%	4386
September	1st to 10th	Day	43% 6% 12% 27% 11% 1	2280
	11th to 20th	Day	40% 6% 13% 28% 13% 1	2181
	21st to end	Day	50% 6% 11% 24% 9%	2043
October	1st to 10th	Day	48% 6% 12% 24% 10% 1	3160
	11th to 20th	Day	53% 6% 11% 22% 8%	3140
	21st to end	Day	60% 5% 13% 17% 5%	3428
November	1st to 10th	Day	57% 5% 13% 18% 6%	1606
	11th to 20th	Day	65% 5% 10% 14% 6% 1	1600
	21st to end	Day	71% 5% 9% 10% 4 1	1600
December	1st to 10th	Day	74% 4 9% 10% 2	2600
	11th to 20th	Day	73% 3 6% 12% 6%	2986
	21st to end	Day	75% 3 4 11% 7%	3801
January	1st to 10th	Night	69% 4 6% 14% 7% 1	6604
	11th to 20th	Night	76% 5% 6% 6% 6% 1	6194
	21st to end	Night	73% 5% 6% 7% 8% 1	6490
February	1st to 10th	Night	67% 5% 8% 13% 6% 1	2600
	11th to 20th	Night	63% 4 8% 17% 7% 1	2535
	21st to end	Night	66% 4 8% 15% 7% 1	2081
March	1st to 10th	Night	55% 6% 11% 16% 11% 1	3418
	11th to 20th	Night	57% 6% 12% 16% 7% 2	3480
	21st to end	Night	49% 5% 7% 23% 14% 2	3817
April	1st to 10th	Night	56% 5% 8% 18% 11% 2	1923
	11th to 20th	Night	50% 4 6% 23% 15% 2	1791
	21st to end	Night	55% 5% 8% 15% 16% 2	1710
May	1st to 10th	Night	43% 6% 12% 25% 12% 2	2755
	11th to 20th	Night	41% 8% 11% 26% 13% 1	2496
	21st to end	Night	37% 7% 11% 25% 17% 2	2739
June	1st to 10th	Night	47% 6% 10% 21% 14% 2	1515
	11th to 20th	Night	38% 5% 12% 25% 19%	1330
	21st to end	Night	44% 7% 14% 24% 11% 1	1330
July	1st to 10th	Night	40% 6% 13% 24% 16% 2	2175
	11th to 20th	Night	38% 5% 11% 34% 11% 1	2398
	21st to end	Night	33% 5% 10% 33% 18% 1	2803
August	1st to 10th	Night	37% 4 16% 25% 16% 1	2814
	11th to 20th	Night	41% 6% 17% 25% 11% 1	2812
	21st to end	Night	35% 5% 11% 35% 13% 1	3238
September	1st to 10th	Night	37% 7% 15% 26% 14% 1	1900
	11th to 20th	Night	35% 6% 13% 31% 14%	1995
	21st to end	Night	44% 6% 11% 28% 11%	2135
October	1st to 10th	Night	40% 5% 10% 27% 17%	3800
	11th to 20th	Night	51% 4 15% 22% 8%	3779
	21st to end	Night	59% 5% 15% 16% 6%	4120
November	1st to 10th	Night	56% 5% 11% 21% 7%	2689
	11th to 20th	Night	60% 5% 11% 16% 7% 1	2800
	21st to end	Night	70% 5% 9% 13% 3	2800
December	1st to 10th	Night	74% 4 10% 8% 3	4580
	11th to 20th	Night	77% 4 5% 9% 5%	5208
	21st to end	Night	75% 3 6% 9% 6%	7134

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% 22% 37% 11% 6% 1	200
	11th to 20th	Day	27% 19% 38% 10% 5% 1	237
	21st to end	Day	28% 17% 36% 16% 3	330
February	1st to 10th	Day	29% 31% 31% 5% 3 1	300
	11th to 20th	Day	31% 24% 37% 7% 2	300
	21st to end	Day	37% 26% 31% 6%	242
March	1st to 10th	Day	27% 19% 37% 15% 3	460
	11th to 20th	Day	23% 22% 35% 16% 4 1	460
	21st to end	Day	31% 16% 32% 15% 5% 1	506
April	1st to 10th	Day	28% 20% 30% 15% 6% 1	460
	11th to 20th	Day	37% 17% 21% 15% 7% 3	452
	21st to end	Day	34% 15% 31% 13% 6% 1	460
May	1st to 10th	Day	28% 12% 30% 20% 7% 3	463
	11th to 20th	Day	23% 14% 28% 22% 9% 3	487
	21st to end	Day	20% 15% 32% 21% 11% 2	529
June	1st to 10th	Day	24% 13% 32% 24% 5% 2	490
	11th to 20th	Day	17% 15% 30% 26% 10% 2	680
	21st to end	Day	22% 13% 35% 21% 7% 2	680
July	1st to 10th	Day	13% 10% 33% 30% 11% 3	671
	11th to 20th	Day	17% 11% 26% 29% 14% 4	532
	21st to end	Day	13% 12% 31% 28% 11% 5%	532
August	1st to 10th	Day	15% 9% 28% 29% 14% 6%	486
	11th to 20th	Day	16% 6% 25% 29% 15% 9%	479
	21st to end	Day	16% 9% 30% 25% 14% 6%	539
September	1st to 10th	Day	18% 10% 30% 22% 13% 6%	490
	11th to 20th	Day	17% 7% 25% 24% 19% 8%	490
	21st to end	Day	21% 15% 23% 26% 12% 3	490
October	1st to 10th	Day	27% 14% 25% 19% 12% 4	490
	11th to 20th	Day	28% 17% 34% 15% 5% 1	490
	21st to end	Day	38% 17% 29% 13% 3	539
November	1st to 10th	Day	38% 16% 29% 15% 2	224
	11th to 20th	Day	30% 25% 31% 12% 4	200
	21st to end	Day	34% 23% 33% 8% 3	200
December	1st to 10th	Day	32% 20% 31% 14% 2 1	200
	11th to 20th	Day	40% 25% 20% 13% 2 1	200
	21st to end	Day	37% 22% 27% 10% 3 1	220
January	1st to 10th	Night	29% 17% 31% 18% 4	913
	11th to 20th	Night	30% 18% 30% 18% 4 1	800
	21st to end	Night	22% 12% 36% 21% 8% 1	880
February	1st to 10th	Night	24% 20% 33% 20% 3	800
	11th to 20th	Night	23% 18% 34% 19% 6%	783
	21st to end	Night	27% 19% 29% 20% 4	647
March	1st to 10th	Night	23% 18% 35% 21% 3	760
	11th to 20th	Night	23% 16% 34% 21% 4 1	760
	21st to end	Night	21% 14% 31% 25% 8% 1	836
April	1st to 10th	Night	28% 14% 32% 21% 5%	760
	11th to 20th	Night	26% 14% 29% 20% 9% 1	667
	21st to end	Night	25% 12% 30% 24% 9%	570
May	1st to 10th	Night	22% 6% 27% 32% 11% 2	524
	11th to 20th	Night	18% 11% 30% 30% 11%	374
	21st to end	Night	12% 9% 32% 34% 12%	411
June	1st to 10th	Night	20% 6% 32% 32% 11%	380
	11th to 20th	Night	16% 9% 25% 36% 14%	380
	21st to end	Night	20% 6% 24% 37% 13%	380
July	1st to 10th	Night	12% 4 21% 44% 18% 1	370
	11th to 20th	Night	15% 4 26% 35% 20% 1	368
	21st to end	Night	11% 4 25% 38% 21% 1	510
August	1st to 10th	Night	14% 4 17% 39% 25% 2	567
	11th to 20th	Night	13% 4 18% 37% 24% 3	564
	21st to end	Night	18% 6% 24% 30% 20% 2	689
September	1st to 10th	Night	16% 7% 26% 32% 17% 3	760
	11th to 20th	Night	15% 6% 25% 29% 21% 4	760
	21st to end	Night	21% 8% 23% 29% 17% 3	760
October	1st to 10th	Night	24% 11% 27% 24% 13% 1	760
	11th to 20th	Night	30% 12% 29% 20% 8% 1	760
	21st to end	Night	34% 15% 28% 19% 4	836
November	1st to 10th	Night	33% 11% 24% 24% 6% 1	780
	11th to 20th	Night	30% 16% 28% 20% 6%	800
	21st to end	Night	35% 14% 28% 19% 4	800
December	1st to 10th	Night	35% 18% 28% 14% 5%	800
	11th to 20th	Night	31% 17% 34% 14% 3 1	800
	21st to end	Night	35% 14% 28% 19% 3	940

Page generated at 2025-02-22 06:51:34. Version ac07

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