Parry Sound
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parry Sound clear sky chart from 2005-11-06 to 2026-08-15.

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 8% 5% 4 4 3 5% 7% 33%	144438
	Night	16% 13% 5% 10% 5% 4 4 3 5% 6% 30%	137526
Transparency	Day	51% 4 10% 22% 11% 1	147996
	Night	55% 4 10% 20% 10% 1	142058
Seeing	Day	24% 13% 32% 21% 8% 2	17364
	Night	24% 10% 29% 26% 10% 1	26334

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	14% 18% 9% 9% 4 3 4 3 4 6% 26%	4094
	11th to 20th	Day	9% 21% 10% 21% 7% 6% 4 3 4 4 11%	4732
	21st to end	Day	11% 15% 7% 18% 8% 6% 5% 4 4 4 18%	5780
February	1st to 10th	Day	13% 20% 6% 13% 7% 5% 3 4 4 4 22%	1890
	11th to 20th	Day	12% 17% 6% 12% 7% 5% 4 2 5% 5% 25%	1843
	21st to end	Day	15% 17% 6% 12% 6% 4 4 3 5% 4 22%	1604
March	1st to 10th	Day	19% 14% 5% 9% 5% 5% 3 3 4 4 29%	4991
	11th to 20th	Day	13% 14% 5% 9% 6% 5% 4 4 5% 7% 26%	5090
	21st to end	Day	18% 15% 6% 8% 4 4 3 3 4 5% 31%	5586
April	1st to 10th	Day	21% 13% 4 6% 4 5% 5% 3 5% 5% 29%	2467
	11th to 20th	Day	21% 11% 3 6% 4 4 4 3 3 5% 36%	2651
	21st to end	Day	21% 11% 3 6% 4 3 4 4 5% 5% 35%	2730
May	1st to 10th	Day	16% 8% 3 6% 4 5% 5% 4 6% 8% 36%	7696
	11th to 20th	Day	14% 9% 3 8% 4 4 4 3 5% 7% 38%	8221
	21st to end	Day	20% 8% 3 5% 4 3 4 3 5% 7% 39%	9060
June	1st to 10th	Day	17% 8% 3 7% 4 4 4 4 5% 7% 37%	3038
	11th to 20th	Day	14% 6% 2 6% 5% 5% 4 4 6% 9% 40%	3150
	21st to end	Day	17% 8% 3 7% 5% 5% 4 5% 6% 8% 35%	3150
July	1st to 10th	Day	15% 6% 2 7% 4 4 5% 4 6% 9% 38%	8879
	11th to 20th	Day	11% 5% 2 5% 4 3 4 3 5% 9% 49%	8700
	21st to end	Day	9% 5% 2 6% 4 4 4 4 6% 8% 48%	8576
August	1st to 10th	Day	11% 7% 3 6% 5% 5% 5% 4 6% 8% 39%	4364
	11th to 20th	Day	16% 6% 2 6% 3 5% 5% 4 6% 9% 38%	4226
	21st to end	Day	9% 5% 2 6% 5% 4 5% 4 6% 9% 45%	4581
September	1st to 10th	Day	14% 7% 3 6% 3 4 5% 4 6% 7% 42%	2400
	11th to 20th	Day	14% 6% 2 5% 4 3 4 4 5% 7% 47%	2255
	21st to end	Day	20% 7% 3 7% 4 4 4 3 5% 6% 36%	2177
October	1st to 10th	Day	21% 7% 2 7% 5% 3 5% 4 5% 6% 35%	2000
	11th to 20th	Day	26% 11% 3 7% 4 5% 5% 3 5% 6% 26%	2000
	21st to end	Day	30% 12% 4 8% 4 3 4 3 4 4 23%	2167
November	1st to 10th	Day	21% 15% 4 9% 5% 4 4 4 4 8% 25%	1709
	11th to 20th	Day	20% 16% 5% 8% 5% 5% 5% 3 5% 6% 22%	1680
	21st to end	Day	22% 23% 4 8% 6% 4 4 3 4 5% 17%	1680
December	1st to 10th	Day	15% 25% 7% 10% 5% 4 5% 3 5% 6% 15%	2680
	11th to 20th	Day	21% 22% 6% 13% 5% 4 3 2 3 4 19%	3038
	21st to end	Day	26% 18% 7% 12% 4 3 3 2 3 4 17%	3553
January	1st to 10th	Night	13% 17% 10% 13% 6% 5% 4 3 4 5% 19%	8831
	11th to 20th	Night	11% 21% 8% 19% 6% 5% 5% 3 4 4 14%	8145
	21st to end	Night	9% 16% 9% 17% 8% 6% 5% 3 4 4 19%	8401
February	1st to 10th	Night	13% 18% 6% 12% 6% 5% 4 4 5% 6% 21%	2730
	11th to 20th	Night	12% 15% 7% 13% 6% 5% 5% 4 5% 5% 24%	2663
	21st to end	Night	15% 17% 6% 11% 6% 5% 5% 3 4 4 23%	2197
March	1st to 10th	Night	17% 13% 4 8% 4 4 4 3 5% 6% 31%	5068
	11th to 20th	Night	12% 14% 5% 9% 5% 5% 4 4 5% 7% 29%	5089
	21st to end	Night	22% 11% 4 7% 4 4 3 3 4 5% 32%	5588
April	1st to 10th	Night	21% 12% 4 7% 4 4 4 3 5% 6% 31%	2153
	11th to 20th	Night	19% 10% 3 8% 5% 4 4 4 4 6% 35%	1935
	21st to end	Night	20% 10% 2 8% 4 6% 5% 3 5% 6% 31%	1890
May	1st to 10th	Night	16% 7% 3 7% 5% 5% 5% 4 6% 8% 36%	5203
	11th to 20th	Night	15% 8% 3 6% 4 4 3 3 5% 7% 42%	4639
	21st to end	Night	17% 7% 2 6% 4 4 4 3 5% 7% 41%	5114
June	1st to 10th	Night	15% 7% 3 6% 4 4 4 4 5% 9% 39%	1577
	11th to 20th	Night	13% 7% 1 5% 3 4 4 4 6% 9% 43%	1470
	21st to end	Night	14% 6% 3 5% 4 5% 4 4 7% 7% 41%	1470
July	1st to 10th	Night	12% 7% 3 7% 4 5% 4 4 5% 8% 42%	4110
	11th to 20th	Night	12% 5% 1 5% 3 3 4 4 5% 8% 49%	4278
	21st to end	Night	11% 6% 2 6% 4 3 3 3 5% 8% 49%	5497
August	1st to 10th	Night	11% 7% 2 6% 3 4 4 3 6% 8% 45%	3005
	11th to 20th	Night	15% 7% 2 6% 3 4 4 3 5% 7% 44%	2911
	21st to end	Night	14% 5% 2 4 3 3 3 3 5% 7% 50%	3284
September	1st to 10th	Night	12% 5% 1 5% 4 4 4 4 5% 8% 47%	2000
	11th to 20th	Night	12% 5% 2 5% 4 3 4 3 5% 6% 51%	2140
	21st to end	Night	18% 7% 2 7% 4 4 4 3 5% 6% 41%	2222
October	1st to 10th	Night	21% 7% 2 6% 4 3 3 3 5% 6% 38%	2400
	11th to 20th	Night	25% 10% 3 9% 5% 5% 4 3 5% 5% 26%	2400
	21st to end	Night	26% 11% 4 9% 4 3 4 3 4 5% 26%	2670
November	1st to 10th	Night	23% 13% 3 8% 4 4 4 3 4 7% 29%	2807
	11th to 20th	Night	18% 16% 4 9% 5% 4 4 3 5% 6% 24%	2940
	21st to end	Night	24% 21% 4 9% 5% 5% 3 3 5% 5% 16%	2940
December	1st to 10th	Night	18% 25% 6% 10% 5% 4 3 3 5% 6% 15%	4720
	11th to 20th	Night	19% 21% 7% 16% 6% 5% 3 3 3 4 14%	5372
	21st to end	Night	22% 21% 5% 13% 5% 4 3 3 3 4 16%	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	62% 3 7% 20% 8%	4095
	11th to 20th	Day	79% 2 5% 8% 5%	4765
	21st to end	Day	70% 4 5% 10% 10% 1	5780
February	1st to 10th	Day	68% 3 7% 16% 5% 1	1890
	11th to 20th	Day	61% 5% 10% 14% 9% 1	1852
	21st to end	Day	65% 5% 7% 18% 5%	1604
March	1st to 10th	Day	59% 6% 11% 9% 14% 2	4994
	11th to 20th	Day	57% 5% 13% 16% 8% 2	5090
	21st to end	Day	54% 6% 8% 19% 10% 2	5586
April	1st to 10th	Day	56% 5% 9% 19% 10% 1	2467
	11th to 20th	Day	51% 5% 7% 22% 14% 1	2651
	21st to end	Day	52% 5% 9% 19% 13% 3	2730
May	1st to 10th	Day	46% 5% 9% 26% 10% 4	7705
	11th to 20th	Day	46% 5% 9% 24% 14% 1	8225
	21st to end	Day	46% 3 10% 23% 15% 2	9061
June	1st to 10th	Day	45% 7% 8% 25% 15% 1	3038
	11th to 20th	Day	42% 5% 10% 26% 16% 1	3150
	21st to end	Day	46% 7% 13% 22% 11% 1	3150
July	1st to 10th	Day	44% 4 14% 26% 11% 1	8806
	11th to 20th	Day	34% 3 12% 39% 12% 1	8619
	21st to end	Day	36% 3 13% 32% 15%	8388
August	1st to 10th	Day	43% 4 13% 28% 11% 1	4351
	11th to 20th	Day	43% 5% 15% 27% 10%	4265
	21st to end	Day	36% 5% 11% 37% 11%	4581
September	1st to 10th	Day	41% 6% 13% 28% 11% 1	2400
	11th to 20th	Day	36% 6% 14% 32% 12%	2255
	21st to end	Day	50% 6% 11% 24% 9%	2177
October	1st to 10th	Day	45% 4 12% 26% 13%	3260
	11th to 20th	Day	51% 5% 13% 25% 6%	3240
	21st to end	Day	61% 3 13% 16% 6%	3481
November	1st to 10th	Day	58% 6% 11% 19% 5%	1709
	11th to 20th	Day	64% 5% 13% 12% 6% 1	1680
	21st to end	Day	70% 5% 12% 9% 3	1680
December	1st to 10th	Day	72% 3 14% 8% 2	2680
	11th to 20th	Day	72% 2 7% 13% 5%	3038
	21st to end	Day	73% 4 5% 12% 6%	3553
January	1st to 10th	Night	69% 3 6% 14% 7%	8831
	11th to 20th	Night	75% 3 5% 8% 7%	8187
	21st to end	Night	70% 3 6% 11% 9% 1	8401
February	1st to 10th	Night	64% 5% 9% 16% 6% 1	2730
	11th to 20th	Night	62% 5% 9% 16% 7% 1	2665
	21st to end	Night	65% 4 9% 15% 7% 1	2197
March	1st to 10th	Night	54% 5% 11% 14% 13% 4	5078
	11th to 20th	Night	54% 4 15% 17% 8% 1	5090
	21st to end	Night	55% 4 7% 19% 13% 2	5588
April	1st to 10th	Night	55% 4 7% 21% 11% 2	2153
	11th to 20th	Night	51% 4 6% 22% 15% 1	1935
	21st to end	Night	54% 4 9% 17% 15% 2	1890
May	1st to 10th	Night	46% 4 7% 27% 13% 3	5210
	11th to 20th	Night	42% 4 9% 25% 19% 1	4640
	21st to end	Night	43% 4 8% 28% 15% 2	5115
June	1st to 10th	Night	43% 5% 9% 23% 16% 3	1577
	11th to 20th	Night	38% 5% 12% 27% 18%	1470
	21st to end	Night	41% 5% 15% 27% 12% 1	1470
July	1st to 10th	Night	42% 3 14% 28% 12% 1	4075
	11th to 20th	Night	36% 2 13% 36% 13% 1	4236
	21st to end	Night	36% 2 9% 35% 17%	5371
August	1st to 10th	Night	37% 3 17% 25% 16% 2	2994
	11th to 20th	Night	41% 4 18% 26% 11% 1	2938
	21st to end	Night	35% 3 11% 37% 13% 1	3284
September	1st to 10th	Night	35% 6% 16% 28% 14% 1	2000
	11th to 20th	Night	33% 6% 15% 33% 13%	2140
	21st to end	Night	45% 5% 13% 26% 12%	2222
October	1st to 10th	Night	40% 3 9% 31% 17%	3920
	11th to 20th	Night	51% 3 15% 25% 7%	3899
	21st to end	Night	56% 3 17% 17% 7%	4306
November	1st to 10th	Night	57% 4 13% 19% 6%	2807
	11th to 20th	Night	61% 4 14% 13% 6% 1	2940
	21st to end	Night	71% 5% 11% 10% 3	2940
December	1st to 10th	Night	73% 3 13% 8% 3	4720
	11th to 20th	Night	76% 4 6% 9% 5%	5372
	21st to end	Night	74% 3 6% 11% 5%	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% 21% 37% 11% 5% 2	220
	11th to 20th	Day	25% 19% 36% 17% 3 1	278
	21st to end	Day	31% 13% 35% 15% 6%	363
February	1st to 10th	Day	32% 20% 35% 10% 3 1	330
	11th to 20th	Day	24% 24% 39% 12% 1	330
	21st to end	Day	36% 22% 34% 7% 1	273
March	1st to 10th	Day	28% 17% 36% 15% 3	513
	11th to 20th	Day	27% 18% 37% 13% 4 1	540
	21st to end	Day	31% 18% 30% 16% 4 1	594
April	1st to 10th	Day	29% 19% 28% 17% 6%	540
	11th to 20th	Day	36% 15% 24% 15% 7% 3	532
	21st to end	Day	31% 15% 33% 15% 6% 1	540
May	1st to 10th	Day	26% 11% 34% 20% 7% 2	543
	11th to 20th	Day	22% 15% 32% 21% 8% 3	567
	21st to end	Day	21% 15% 32% 20% 12% 1	617
June	1st to 10th	Day	22% 12% 31% 27% 7% 1	668
	11th to 20th	Day	19% 11% 35% 25% 9% 1	780
	21st to end	Day	21% 9% 37% 23% 8% 1	780
July	1st to 10th	Day	14% 7% 35% 29% 13% 2	771
	11th to 20th	Day	13% 10% 31% 30% 12% 3	705
	21st to end	Day	12% 6% 37% 29% 11% 4	620
August	1st to 10th	Day	15% 10% 24% 32% 14% 5%	566
	11th to 20th	Day	16% 4 27% 29% 15% 8%	535
	21st to end	Day	16% 11% 28% 26% 14% 5%	583
September	1st to 10th	Day	16% 10% 30% 26% 13% 5%	530
	11th to 20th	Day	15% 5% 24% 28% 19% 9%	530
	21st to end	Day	22% 8% 24% 28% 15% 3	530
October	1st to 10th	Day	25% 12% 26% 21% 13% 2	530
	11th to 20th	Day	29% 14% 35% 16% 4 2	530
	21st to end	Day	38% 15% 30% 16% 2 1	550
November	1st to 10th	Day	39% 15% 30% 13% 4	254
	11th to 20th	Day	26% 24% 34% 14% 2	220
	21st to end	Day	37% 19% 31% 10% 2	220
December	1st to 10th	Day	30% 19% 33% 15% 4	220
	11th to 20th	Day	37% 19% 28% 14% 2	220
	21st to end	Day	38% 19% 29% 11% 4	242
January	1st to 10th	Night	27% 14% 34% 20% 3 1	1050
	11th to 20th	Night	31% 14% 31% 19% 4	922
	21st to end	Night	21% 10% 36% 23% 8% 1	924
February	1st to 10th	Night	23% 17% 33% 23% 4	840
	11th to 20th	Night	22% 13% 36% 22% 7%	823
	21st to end	Night	25% 16% 32% 23% 4	692
March	1st to 10th	Night	21% 15% 36% 23% 4	840
	11th to 20th	Night	23% 12% 37% 24% 4 1	840
	21st to end	Night	22% 11% 33% 26% 8% 1	924
April	1st to 10th	Night	27% 13% 31% 25% 5%	840
	11th to 20th	Night	24% 12% 29% 24% 10% 1	691
	21st to end	Night	26% 10% 27% 26% 10%	630
May	1st to 10th	Night	21% 6% 26% 34% 12% 2	614
	11th to 20th	Night	18% 7% 28% 35% 11% 1	414
	21st to end	Night	15% 6% 31% 34% 13%	455
June	1st to 10th	Night	17% 5% 29% 36% 12% 1	420
	11th to 20th	Night	18% 8% 24% 37% 13%	420
	21st to end	Night	16% 6% 25% 35% 17% 1	420
July	1st to 10th	Night	11% 3 18% 47% 19% 1	410
	11th to 20th	Night	12% 3 25% 39% 20% 1	408
	21st to end	Night	14% 4 22% 36% 22% 1	603
August	1st to 10th	Night	14% 3 19% 36% 25% 3	627
	11th to 20th	Night	15% 2 19% 35% 25% 4	606
	21st to end	Night	18% 5% 21% 31% 22% 2	695
September	1st to 10th	Night	15% 5% 26% 30% 20% 4	800
	11th to 20th	Night	15% 6% 22% 32% 22% 4	800
	21st to end	Night	22% 6% 20% 31% 18% 3	800
October	1st to 10th	Night	24% 9% 27% 27% 12% 1	800
	11th to 20th	Night	32% 10% 26% 24% 7% 1	800
	21st to end	Night	32% 12% 30% 23% 3	880
November	1st to 10th	Night	33% 8% 30% 21% 8% 1	820
	11th to 20th	Night	29% 15% 30% 22% 4	840
	21st to end	Night	38% 12% 27% 19% 4	840
December	1st to 10th	Night	33% 16% 30% 16% 5%	840
	11th to 20th	Night	31% 17% 33% 15% 3 1	851
	21st to end	Night	34% 14% 30% 17% 4	1155

Page generated at 2026-08-12 03:37:16. Version ac07

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