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 2024-10-24.

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% 6% 33%	101625
	Night	17% 13% 4 9% 5% 4 4 3 5% 6% 31%	97170
Transparency	Day	51% 6% 11% 21% 10% 1	101379
	Night	55% 5% 11% 19% 10% 1	97037
Seeing	Day	23% 13% 31% 21% 9% 2	15031
	Night	24% 10% 28% 26% 10% 1	24057

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	16% 24% 13% 11% 4 3 3 2 2 4 18%	2208
	11th to 20th	Day	11% 18% 7% 22% 8% 6% 4 2 4 4 14%	2555
	21st to end	Day	17% 22% 8% 12% 5% 5% 4 2 3 4 18%	3124
February	1st to 10th	Day	13% 20% 7% 13% 7% 4 3 4 4 4 21%	1710
	11th to 20th	Day	12% 17% 6% 11% 7% 5% 3 2 5% 5% 26%	1663
	21st to end	Day	15% 17% 6% 12% 6% 4 4 3 4 4 23%	1456
March	1st to 10th	Day	19% 15% 4 8% 5% 5% 4 4 4 5% 29%	3396
	11th to 20th	Day	11% 17% 6% 10% 7% 5% 4 3 5% 6% 27%	3480
	21st to end	Day	14% 12% 5% 8% 4 4 4 3 5% 6% 36%	3815
April	1st to 10th	Day	21% 13% 5% 6% 4 5% 5% 3 5% 6% 29%	2232
	11th to 20th	Day	21% 11% 3 6% 5% 4 4 3 4 5% 36%	2395
	21st to end	Day	22% 10% 3 6% 5% 3 3 3 4 5% 35%	2470
May	1st to 10th	Day	19% 7% 2 7% 4 5% 5% 4 5% 7% 34%	4135
	11th to 20th	Day	13% 8% 3 7% 4 3 4 3 6% 8% 41%	4398
	21st to end	Day	18% 6% 2 5% 3 3 4 3 5% 7% 43%	4837
June	1st to 10th	Day	17% 8% 3 7% 4 4 4 4 5% 8% 37%	2748
	11th to 20th	Day	13% 6% 2 6% 5% 5% 4 4 6% 9% 40%	2850
	21st to end	Day	18% 8% 2 7% 5% 4 4 5% 5% 8% 35%	2850
July	1st to 10th	Day	16% 6% 2 7% 4 4 5% 4 6% 8% 37%	4760
	11th to 20th	Day	13% 6% 2 6% 4 4 5% 4 5% 8% 45%	4664
	21st to end	Day	10% 6% 2 5% 4 4 4 3 5% 7% 50%	4593
August	1st to 10th	Day	11% 7% 3 6% 5% 5% 5% 4 7% 8% 39%	4104
	11th to 20th	Day	16% 6% 2 6% 3 5% 5% 4 6% 9% 38%	4044
	21st to end	Day	9% 5% 2 6% 5% 4 5% 4 6% 9% 46%	4441
September	1st to 10th	Day	14% 6% 3 6% 3 4 5% 4 6% 7% 42%	2280
	11th to 20th	Day	15% 7% 2 5% 4 3 4 3 5% 7% 46%	2142
	21st to end	Day	20% 7% 3 7% 4 5% 4 3 5% 6% 36%	2068
October	1st to 10th	Day	21% 8% 2 7% 5% 3 5% 4 5% 6% 34%	1900
	11th to 20th	Day	27% 12% 3 8% 4 5% 5% 3 5% 5% 25%	1900
	21st to end	Day	31% 13% 4 8% 4 3 4 3 4 4 22%	1981
November	1st to 10th	Day	20% 14% 3 8% 5% 4 4 4 4 8% 25%	1543
	11th to 20th	Day	21% 16% 4 8% 5% 5% 5% 3 5% 6% 22%	1520
	21st to end	Day	23% 21% 4 8% 6% 4 5% 3 4 5% 17%	1520
December	1st to 10th	Day	17% 27% 7% 9% 4 3 4 2 4 5% 17%	1520
	11th to 20th	Day	21% 23% 5% 10% 5% 4 3 2 2 4 21%	1892
	21st to end	Day	26% 20% 6% 12% 5% 4 4 3 4 4 13%	2431
January	1st to 10th	Night	17% 20% 12% 14% 6% 5% 3 3 3 4 14%	4748
	11th to 20th	Night	15% 15% 6% 20% 6% 5% 5% 3 5% 4 14%	4403
	21st to end	Night	16% 20% 8% 13% 6% 4 4 2 4 4 17%	4532
February	1st to 10th	Night	14% 19% 6% 12% 7% 5% 4 4 5% 6% 20%	2470
	11th to 20th	Night	12% 15% 7% 12% 6% 5% 4 3 5% 4 26%	2403
	21st to end	Night	15% 17% 5% 11% 6% 4 5% 4 4 4 24%	1994
March	1st to 10th	Night	15% 13% 5% 8% 5% 4 4 3 5% 6% 32%	3443
	11th to 20th	Night	13% 15% 5% 9% 5% 4 3 3 4 6% 32%	3479
	21st to end	Night	15% 11% 3 7% 5% 5% 4 3 5% 6% 36%	3817
April	1st to 10th	Night	22% 12% 3 7% 4 4 4 3 5% 6% 31%	1948
	11th to 20th	Night	19% 10% 3 7% 5% 3 4 4 5% 6% 35%	1749
	21st to end	Night	21% 10% 2 8% 4 6% 5% 3 5% 6% 31%	1710
May	1st to 10th	Night	16% 7% 3 7% 5% 4 5% 4 6% 8% 36%	2806
	11th to 20th	Night	13% 7% 2 7% 5% 4 4 4 6% 8% 40%	2495
	21st to end	Night	12% 7% 2 7% 4 4 5% 4 6% 8% 42%	2738
June	1st to 10th	Night	16% 7% 3 7% 4 4 4 4 5% 8% 38%	1427
	11th to 20th	Night	12% 7% 1 4 3 4 4 4 6% 9% 44%	1330
	21st to end	Night	15% 7% 3 5% 3 4 4 4 7% 7% 41%	1330
July	1st to 10th	Night	11% 7% 3 7% 3 4 4 3 5% 7% 47%	2210
	11th to 20th	Night	15% 6% 1 5% 3 3 3 3 5% 7% 48%	2300
	21st to end	Night	9% 6% 2 5% 3 3 4 4 5% 7% 51%	2956
August	1st to 10th	Night	11% 7% 2 6% 3 4 4 3 6% 8% 45%	2825
	11th to 20th	Night	15% 7% 2 6% 4 4 4 3 5% 7% 43%	2785
	21st to end	Night	14% 5% 2 4 3 3 4 3 5% 7% 50%	3183
September	1st to 10th	Night	11% 5% 1 6% 4 4 4 4 5% 8% 47%	1900
	11th to 20th	Night	12% 5% 2 5% 4 3 4 3 5% 7% 50%	2033
	21st to end	Night	18% 6% 2 6% 4 5% 4 3 5% 6% 41%	2111
October	1st to 10th	Night	22% 8% 3 7% 4 4 3 3 5% 5% 36%	2280
	11th to 20th	Night	25% 10% 3 9% 5% 5% 4 3 4 5% 25%	2280
	21st to end	Night	27% 11% 4 10% 4 3 4 3 4 5% 24%	2439
November	1st to 10th	Night	23% 13% 3 8% 4 4 4 2 4 7% 29%	2533
	11th to 20th	Night	19% 16% 4 9% 5% 4 4 4 5% 6% 24%	2660
	21st to end	Night	24% 20% 4 9% 5% 5% 3 3 5% 5% 16%	2660
December	1st to 10th	Night	20% 26% 6% 11% 5% 4 3 3 5% 5% 13%	2660
	11th to 20th	Night	21% 22% 6% 11% 5% 4 3 3 4 4 17%	3297
	21st to end	Night	23% 23% 6% 13% 5% 4 3 3 3 4 13%	5236

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	73% 5% 9% 8% 5%	2209
	11th to 20th	Day	75% 4 8% 8% 4 1	2555
	21st to end	Day	70% 7% 7% 9% 6% 1	3124
February	1st to 10th	Day	68% 4 7% 16% 4 1	1710
	11th to 20th	Day	60% 6% 10% 14% 9% 1	1672
	21st to end	Day	64% 6% 7% 17% 6%	1456
March	1st to 10th	Day	56% 8% 13% 11% 11%	3399
	11th to 20th	Day	56% 7% 10% 18% 7% 1	3480
	21st to end	Day	45% 9% 10% 20% 13% 2	3815
April	1st to 10th	Day	55% 6% 9% 18% 10% 1	2232
	11th to 20th	Day	51% 5% 7% 22% 14% 1	2395
	21st to end	Day	51% 6% 9% 18% 14% 3	2470
May	1st to 10th	Day	45% 10% 7% 24% 12% 2	4147
	11th to 20th	Day	40% 8% 12% 29% 10% 1	4402
	21st to end	Day	41% 6% 13% 20% 17% 3	4837
June	1st to 10th	Day	45% 7% 9% 25% 13% 1	2748
	11th to 20th	Day	41% 6% 10% 25% 17% 1	2850
	21st to end	Day	46% 7% 12% 21% 11% 1	2850
July	1st to 10th	Day	45% 5% 15% 24% 10% 1	4686
	11th to 20th	Day	39% 4 14% 32% 10%	4583
	21st to end	Day	34% 4 11% 31% 19% 1	4447
August	1st to 10th	Day	43% 5% 12% 28% 11% 1	4091
	11th to 20th	Day	43% 5% 15% 27% 10%	4083
	21st to end	Day	36% 5% 11% 37% 11%	4441
September	1st to 10th	Day	40% 7% 12% 29% 11% 1	2280
	11th to 20th	Day	37% 6% 14% 30% 12%	2142
	21st to end	Day	49% 6% 11% 24% 9%	2068
October	1st to 10th	Day	51% 7% 11% 18% 12% 1	1900
	11th to 20th	Day	61% 5% 12% 15% 6%	1900
	21st to end	Day	67% 5% 10% 13% 6%	1981
November	1st to 10th	Day	57% 6% 12% 19% 5%	1543
	11th to 20th	Day	64% 5% 13% 12% 6% 1	1520
	21st to end	Day	70% 6% 13% 9% 3 1	1520
December	1st to 10th	Day	70% 5% 11% 10% 3 1	1520
	11th to 20th	Day	70% 3 8% 11% 6%	1892
	21st to end	Day	76% 5% 7% 9% 2	2431
January	1st to 10th	Night	76% 5% 6% 8% 4	4748
	11th to 20th	Night	73% 6% 8% 8% 4	4403
	21st to end	Night	71% 5% 7% 11% 6% 1	4532
February	1st to 10th	Night	66% 5% 9% 15% 5% 1	2470
	11th to 20th	Night	61% 5% 10% 16% 7% 1	2405
	21st to end	Night	63% 5% 9% 15% 7% 1	1994
March	1st to 10th	Night	51% 7% 12% 16% 12% 1	3453
	11th to 20th	Night	52% 6% 13% 18% 8% 2	3480
	21st to end	Night	48% 6% 9% 23% 13% 2	3817
April	1st to 10th	Night	54% 5% 7% 21% 11% 2	1948
	11th to 20th	Night	50% 5% 6% 21% 16% 1	1749
	21st to end	Night	54% 4 9% 15% 16% 2	1710
May	1st to 10th	Night	43% 7% 11% 25% 11% 2	2813
	11th to 20th	Night	40% 6% 11% 26% 16% 1	2496
	21st to end	Night	38% 7% 12% 24% 17% 3	2739
June	1st to 10th	Night	45% 6% 10% 23% 14% 2	1427
	11th to 20th	Night	36% 5% 12% 27% 19%	1330
	21st to end	Night	40% 5% 14% 26% 13% 1	1330
July	1st to 10th	Night	38% 3 14% 26% 16% 3	2175
	11th to 20th	Night	37% 3 12% 37% 11% 1	2258
	21st to end	Night	34% 4 9% 31% 22% 1	2862
August	1st to 10th	Night	37% 4 18% 24% 16% 2	2814
	11th to 20th	Night	41% 4 18% 25% 11% 1	2812
	21st to end	Night	35% 3 11% 37% 14% 1	3183
September	1st to 10th	Night	35% 6% 16% 28% 15% 1	1900
	11th to 20th	Night	33% 7% 15% 32% 12%	2033
	21st to end	Night	44% 5% 14% 26% 11%	2111
October	1st to 10th	Night	49% 5% 11% 21% 13%	2280
	11th to 20th	Night	61% 5% 11% 18% 5%	2280
	21st to end	Night	64% 4 10% 14% 7% 1	2439
November	1st to 10th	Night	56% 5% 13% 19% 6%	2533
	11th to 20th	Night	61% 5% 14% 13% 6% 1	2660
	21st to end	Night	70% 5% 12% 10% 3	2660
December	1st to 10th	Night	74% 6% 9% 9% 3	2660
	11th to 20th	Night	71% 6% 7% 11% 5%	3297
	21st to end	Night	77% 5% 7% 9% 3	5236

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% 24% 32% 11% 6% 2	180
	11th to 20th	Day	24% 19% 36% 18% 3 1	227
	21st to end	Day	32% 11% 36% 14% 6%	297
February	1st to 10th	Day	32% 20% 36% 8% 3 1	270
	11th to 20th	Day	22% 23% 42% 12% 1	270
	21st to end	Day	37% 24% 32% 7%	225
March	1st to 10th	Day	27% 17% 35% 17% 3	435
	11th to 20th	Day	23% 17% 39% 15% 5% 1	460
	21st to end	Day	28% 17% 32% 17% 5% 1	506
April	1st to 10th	Day	27% 18% 29% 18% 7%	460
	11th to 20th	Day	34% 16% 24% 15% 8% 3	452
	21st to end	Day	30% 15% 33% 15% 6% 1	460
May	1st to 10th	Day	26% 10% 33% 21% 8% 2	463
	11th to 20th	Day	22% 14% 30% 22% 9% 3	487
	21st to end	Day	18% 14% 32% 22% 13% 2	529
June	1st to 10th	Day	21% 12% 30% 27% 7% 2	578
	11th to 20th	Day	17% 10% 35% 26% 10% 2	680
	21st to end	Day	21% 9% 35% 24% 9% 1	680
July	1st to 10th	Day	13% 6% 35% 30% 14% 2	671
	11th to 20th	Day	13% 8% 30% 31% 13% 4	611
	21st to end	Day	13% 6% 34% 30% 12% 5%	532
August	1st to 10th	Day	15% 9% 24% 32% 14% 5%	486
	11th to 20th	Day	17% 4 25% 29% 16% 9%	479
	21st to end	Day	17% 10% 28% 26% 15% 5%	539
September	1st to 10th	Day	15% 10% 31% 26% 13% 5%	490
	11th to 20th	Day	16% 6% 25% 27% 20% 7%	490
	21st to end	Day	21% 9% 24% 28% 16% 3	490
October	1st to 10th	Day	27% 13% 26% 20% 13% 2	490
	11th to 20th	Day	29% 14% 35% 17% 4 2	490
	21st to end	Day	38% 15% 31% 14% 3 1	478
November	1st to 10th	Day	35% 16% 31% 14% 3	208
	11th to 20th	Day	24% 23% 36% 15% 2	180
	21st to end	Day	35% 18% 33% 11% 2 1	180
December	1st to 10th	Day	30% 20% 32% 14% 4	180
	11th to 20th	Day	35% 21% 29% 12% 2 1	180
	21st to end	Day	36% 21% 30% 9% 4	198
January	1st to 10th	Night	28% 15% 31% 21% 3 1	950
	11th to 20th	Night	31% 14% 30% 19% 5%	835
	21st to end	Night	22% 9% 36% 23% 8% 1	836
February	1st to 10th	Night	24% 18% 33% 22% 3	760
	11th to 20th	Night	21% 13% 36% 22% 7%	743
	21st to end	Night	25% 17% 31% 22% 4	628
March	1st to 10th	Night	20% 15% 35% 24% 5%	760
	11th to 20th	Night	21% 12% 36% 25% 5% 1	760
	21st to end	Night	20% 10% 34% 27% 9% 1	836
April	1st to 10th	Night	27% 11% 31% 26% 5%	760
	11th to 20th	Night	24% 12% 29% 24% 9% 1	625
	21st to end	Night	26% 10% 27% 25% 11%	570
May	1st to 10th	Night	21% 5% 26% 34% 12% 2	556
	11th to 20th	Night	17% 6% 27% 37% 11% 1	374
	21st to end	Night	13% 6% 31% 35% 14%	411
June	1st to 10th	Night	17% 4 29% 36% 12% 1	380
	11th to 20th	Night	18% 7% 23% 37% 15%	380
	21st to end	Night	17% 6% 24% 34% 17% 2	380
July	1st to 10th	Night	11% 3 18% 46% 20% 2	370
	11th to 20th	Night	13% 3 24% 37% 22% 1	368
	21st to end	Night	14% 4 22% 35% 23% 1	545
August	1st to 10th	Night	14% 3 19% 35% 26% 3	567
	11th to 20th	Night	14% 2 19% 34% 26% 5%	564
	21st to end	Night	18% 6% 20% 32% 22% 3	660
September	1st to 10th	Night	14% 5% 27% 30% 19% 4	760
	11th to 20th	Night	15% 6% 22% 31% 22% 4	760
	21st to end	Night	22% 7% 21% 31% 17% 4	760
October	1st to 10th	Night	25% 10% 27% 25% 12% 1	760
	11th to 20th	Night	32% 10% 26% 23% 8% 1	760
	21st to end	Night	33% 12% 29% 21% 3	805
November	1st to 10th	Night	33% 7% 29% 21% 9% 1	740
	11th to 20th	Night	29% 15% 29% 22% 5%	760
	21st to end	Night	38% 11% 27% 20% 4	760
December	1st to 10th	Night	35% 15% 30% 16% 5%	760
	11th to 20th	Night	32% 17% 32% 15% 3 1	769
	21st to end	Night	33% 14% 30% 18% 3	1045

Page generated at 2024-10-21 02:20:02. Version ac07

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