Quyon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Quyon clear sky chart from 2005-11-06 to 2024-02-20.

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% 9% 4 7% 6% 3 5% 5% 5% 6% 32%	78204
	Night	17% 11% 4 8% 6% 3 4 4 5% 6% 31%	80966
Transparency	Day	36% 37% 8% 12% 6% 1	77909
	Night	38% 35% 8% 12% 5% 1	80795
Seeing	Day	24% 16% 30% 20% 8% 2	13423
	Night	23% 13% 29% 25% 9% 1	22717

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% 16% 7% 11% 8% 4 5% 4 4 4 21%	2517
	11th to 20th	Day	14% 13% 6% 14% 8% 4 5% 4 5% 5% 21%	2520
	21st to end	Day	13% 17% 7% 11% 9% 5% 6% 5% 4 5% 18%	2914
February	1st to 10th	Day	14% 13% 6% 12% 7% 4 6% 5% 4 5% 23%	1710
	11th to 20th	Day	12% 14% 6% 10% 6% 4 4 4 4 7% 28%	1654
	21st to end	Day	19% 11% 5% 8% 6% 4 5% 5% 5% 5% 25%	1463
March	1st to 10th	Day	16% 10% 4 10% 7% 4 5% 4 4 6% 30%	1815
	11th to 20th	Day	15% 12% 5% 8% 8% 3 5% 4 4 5% 31%	1980
	21st to end	Day	19% 9% 4 5% 6% 3 4 4 4 6% 36%	2278
April	1st to 10th	Day	22% 12% 3 6% 5% 3 4 4 4 5% 32%	2160
	11th to 20th	Day	21% 9% 3 6% 5% 3 4 3 4 5% 37%	2134
	21st to end	Day	22% 10% 4 7% 5% 3 3 4 4 5% 32%	2297
May	1st to 10th	Day	20% 8% 4 6% 6% 3 4 4 4 6% 36%	2520
	11th to 20th	Day	15% 7% 4 6% 6% 4 5% 4 4 6% 39%	2478
	21st to end	Day	15% 6% 3 5% 6% 3 6% 5% 6% 7% 38%	2725
June	1st to 10th	Day	20% 8% 3 6% 6% 3 6% 5% 6% 7% 30%	2520
	11th to 20th	Day	15% 5% 3 5% 5% 4 5% 5% 6% 7% 40%	2520
	21st to end	Day	17% 7% 3 5% 6% 4 5% 6% 7% 8% 31%	2520
July	1st to 10th	Day	11% 5% 2 6% 5% 3 6% 7% 8% 9% 39%	2520
	11th to 20th	Day	11% 6% 3 6% 6% 3 5% 6% 7% 8% 40%	2520
	21st to end	Day	11% 5% 2 5% 5% 4 6% 5% 7% 10% 39%	2744
August	1st to 10th	Day	10% 5% 3 7% 6% 4 6% 5% 6% 8% 40%	2450
	11th to 20th	Day	11% 6% 3 6% 6% 4 5% 5% 7% 8% 39%	2299
	21st to end	Day	13% 6% 3 6% 5% 3 5% 5% 6% 9% 39%	2376
September	1st to 10th	Day	13% 5% 3 5% 5% 3 6% 5% 6% 8% 42%	2160
	11th to 20th	Day	13% 5% 3 5% 5% 3 4 5% 5% 7% 45%	2160
	21st to end	Day	16% 6% 2 6% 5% 3 5% 5% 5% 8% 38%	1913
October	1st to 10th	Day	21% 6% 3 6% 6% 2 5% 4 5% 6% 35%	1800
	11th to 20th	Day	23% 9% 4 7% 6% 4 4 5% 5% 7% 27%	1800
	21st to end	Day	27% 9% 3 6% 6% 4 4 5% 4 5% 27%	1850
November	1st to 10th	Day	16% 8% 3 6% 6% 3 6% 5% 6% 7% 34%	1649
	11th to 20th	Day	20% 11% 5% 8% 7% 4 4 6% 4 7% 26%	1520
	21st to end	Day	22% 13% 5% 9% 8% 5% 5% 4 4 6% 19%	1520
December	1st to 10th	Day	21% 17% 6% 10% 7% 3 5% 4 5% 6% 15%	1520
	11th to 20th	Day	20% 13% 5% 9% 7% 4 4 4 4 6% 24%	1906
	21st to end	Day	29% 17% 5% 12% 5% 2 4 3 2 3 19%	2772
January	1st to 10th	Night	17% 18% 7% 12% 8% 3 4 3 4 6% 18%	4429
	11th to 20th	Night	12% 13% 6% 12% 10% 4 5% 5% 4 6% 23%	4440
	21st to end	Night	16% 19% 7% 9% 8% 5% 4 4 3 4 20%	4728
February	1st to 10th	Night	13% 13% 6% 11% 8% 4 5% 5% 5% 6% 23%	2470
	11th to 20th	Night	13% 13% 6% 10% 8% 3 4 5% 4 5% 29%	2397
	21st to end	Night	16% 12% 5% 9% 7% 3 6% 4 5% 6% 28%	1792
March	1st to 10th	Night	16% 14% 5% 7% 8% 4 5% 4 4 4 29%	2128
	11th to 20th	Night	16% 11% 5% 9% 6% 3 4 3 4 5% 34%	1979
	21st to end	Night	16% 9% 3 7% 6% 3 4 3 4 6% 39%	2077
April	1st to 10th	Night	21% 9% 4 7% 5% 4 3 4 5% 6% 33%	1800
	11th to 20th	Night	18% 9% 3 6% 6% 3 5% 4 4 6% 35%	1775
	21st to end	Night	20% 9% 4 7% 6% 3 4 4 5% 5% 33%	1678
May	1st to 10th	Night	20% 8% 3 4 5% 3 4 5% 5% 7% 37%	1440
	11th to 20th	Night	18% 8% 3 4 4 2 4 4 4 8% 40%	1415
	21st to end	Night	13% 5% 2 6% 5% 2 5% 5% 5% 9% 43%	1550
June	1st to 10th	Night	16% 6% 3 6% 6% 3 5% 6% 7% 9% 34%	1440
	11th to 20th	Night	14% 5% 3 5% 5% 3 4 5% 6% 8% 43%	1440
	21st to end	Night	15% 6% 3 5% 5% 3 5% 5% 7% 9% 36%	1440
July	1st to 10th	Night	10% 5% 2 5% 6% 3 4 5% 6% 9% 46%	1440
	11th to 20th	Night	11% 5% 3 6% 5% 3 5% 5% 6% 9% 43%	1440
	21st to end	Night	10% 4 2 4 6% 4 5% 5% 6% 10% 43%	1574
August	1st to 10th	Night	8% 7% 3 6% 6% 3 4 6% 5% 10% 42%	1485
	11th to 20th	Night	9% 5% 2 6% 5% 4 5% 5% 6% 8% 45%	1598
	21st to end	Night	11% 6% 2 6% 4 3 4 5% 5% 9% 44%	1966
September	1st to 10th	Night	11% 5% 2 6% 6% 3 5% 4 4 8% 45%	1800
	11th to 20th	Night	14% 5% 2 4 4 3 4 4 5% 6% 48%	1800
	21st to end	Night	17% 7% 3 6% 5% 3 4 3 5% 7% 42%	2043
October	1st to 10th	Night	18% 8% 3 5% 5% 4 5% 4 5% 6% 38%	2160
	11th to 20th	Night	22% 8% 3 8% 6% 4 5% 4 5% 7% 29%	2160
	21st to end	Night	23% 11% 3 7% 7% 3 4 4 5% 6% 27%	2504
November	1st to 10th	Night	19% 9% 4 7% 6% 3 3 4 5% 6% 34%	2426
	11th to 20th	Night	20% 11% 4 7% 6% 4 5% 5% 5% 6% 27%	2660
	21st to end	Night	22% 13% 4 8% 6% 4 4 5% 5% 7% 21%	2660
December	1st to 10th	Night	22% 17% 5% 9% 7% 4 5% 6% 5% 5% 16%	2660
	11th to 20th	Night	22% 15% 5% 9% 6% 3 4 3 3 5% 25%	3288
	21st to end	Night	29% 18% 4 10% 5% 3 4 3 3 3 18%	4884

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	50% 28% 11% 7% 4	2518
	11th to 20th	Day	50% 27% 9% 10% 4	2520
	21st to end	Day	57% 25% 7% 7% 4	2914
February	1st to 10th	Day	41% 35% 8% 13% 3 1	1710
	11th to 20th	Day	39% 37% 10% 9% 5% 1	1663
	21st to end	Day	41% 37% 7% 10% 5%	1463
March	1st to 10th	Day	38% 37% 8% 12% 5%	1818
	11th to 20th	Day	37% 37% 9% 10% 6%	1980
	21st to end	Day	33% 37% 6% 13% 8% 3	2278
April	1st to 10th	Day	36% 36% 5% 15% 7% 2	2160
	11th to 20th	Day	34% 36% 6% 13% 11% 1	2134
	21st to end	Day	37% 37% 5% 9% 9% 3	2297
May	1st to 10th	Day	32% 38% 5% 13% 9% 3	2520
	11th to 20th	Day	31% 37% 5% 14% 11% 2	2482
	21st to end	Day	28% 38% 8% 14% 11% 2	2725
June	1st to 10th	Day	36% 39% 7% 10% 7%	2520
	11th to 20th	Day	28% 39% 7% 17% 8% 1	2520
	21st to end	Day	34% 40% 9% 10% 6%	2520
July	1st to 10th	Day	27% 41% 8% 18% 6%	2450
	11th to 20th	Day	27% 41% 11% 14% 8%	2445
	21st to end	Day	26% 41% 10% 15% 7%	2591
August	1st to 10th	Day	30% 39% 9% 17% 6%	2436
	11th to 20th	Day	25% 39% 12% 17% 6% 1	2299
	21st to end	Day	27% 38% 10% 15% 9% 1	2376
September	1st to 10th	Day	26% 38% 10% 20% 6%	2160
	11th to 20th	Day	27% 39% 9% 17% 8%	2160
	21st to end	Day	31% 39% 8% 17% 5%	1913
October	1st to 10th	Day	34% 38% 8% 14% 6% 1	1800
	11th to 20th	Day	39% 38% 10% 10% 4	1800
	21st to end	Day	39% 38% 8% 9% 5%	1850
November	1st to 10th	Day	26% 43% 10% 17% 4	1649
	11th to 20th	Day	37% 41% 9% 6% 7%	1520
	21st to end	Day	41% 41% 9% 6% 2	1520
December	1st to 10th	Day	45% 41% 7% 5% 2	1520
	11th to 20th	Day	43% 34% 11% 9% 4	1906
	21st to end	Day	58% 25% 5% 11% 1	2772
January	1st to 10th	Night	53% 27% 12% 7% 2	4429
	11th to 20th	Night	48% 28% 12% 9% 2	4440
	21st to end	Night	57% 24% 7% 7% 4	4728
February	1st to 10th	Night	42% 36% 7% 11% 4 1	2470
	11th to 20th	Night	40% 36% 8% 12% 4 1	2399
	21st to end	Night	38% 37% 7% 12% 5% 1	1792
March	1st to 10th	Night	39% 37% 6% 13% 4 1	2138
	11th to 20th	Night	38% 36% 9% 11% 5% 1	1980
	21st to end	Night	31% 37% 7% 13% 10% 3	2077
April	1st to 10th	Night	36% 37% 6% 11% 9% 2	1800
	11th to 20th	Night	34% 36% 6% 14% 9% 1	1775
	21st to end	Night	37% 36% 4 10% 10% 3	1678
May	1st to 10th	Night	31% 37% 5% 13% 10% 5%	1440
	11th to 20th	Night	27% 38% 6% 15% 11% 3	1416
	21st to end	Night	25% 38% 9% 13% 13% 2	1551
June	1st to 10th	Night	30% 40% 11% 13% 4 1	1440
	11th to 20th	Night	26% 38% 10% 16% 8% 2	1440
	21st to end	Night	30% 40% 10% 12% 8%	1440
July	1st to 10th	Night	23% 43% 9% 17% 7% 1	1400
	11th to 20th	Night	26% 40% 8% 16% 9%	1392
	21st to end	Night	24% 40% 10% 15% 10%	1486
August	1st to 10th	Night	27% 39% 11% 15% 8%	1475
	11th to 20th	Night	22% 39% 11% 20% 8%	1598
	21st to end	Night	25% 40% 9% 18% 7%	1966
September	1st to 10th	Night	26% 37% 9% 18% 9%	1800
	11th to 20th	Night	25% 39% 10% 21% 6% 1	1800
	21st to end	Night	30% 37% 9% 19% 5%	2043
October	1st to 10th	Night	32% 39% 8% 13% 8%	2160
	11th to 20th	Night	38% 38% 7% 12% 5%	2160
	21st to end	Night	38% 38% 10% 9% 5%	2504
November	1st to 10th	Night	29% 42% 9% 14% 5%	2426
	11th to 20th	Night	34% 41% 8% 9% 6% 1	2660
	21st to end	Night	39% 42% 8% 9% 2	2660
December	1st to 10th	Night	45% 42% 6% 6% 1	2660
	11th to 20th	Night	44% 33% 7% 11% 4	3288
	21st to end	Night	58% 25% 5% 10% 2	4884

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% 24% 32% 17% 3	180
	11th to 20th	Day	27% 19% 37% 13% 3 1	180
	21st to end	Day	21% 20% 35% 19% 5%	240
February	1st to 10th	Day	30% 26% 31% 11% 2	270
	11th to 20th	Day	28% 28% 35% 7%	267
	21st to end	Day	34% 22% 29% 14% 1	329
March	1st to 10th	Day	27% 20% 33% 15% 4	420
	11th to 20th	Day	27% 21% 32% 15% 4 1	420
	21st to end	Day	31% 19% 29% 16% 5% 1	462
April	1st to 10th	Day	33% 22% 24% 15% 5%	420
	11th to 20th	Day	34% 19% 21% 15% 10% 1	412
	21st to end	Day	30% 20% 31% 12% 6%	420
May	1st to 10th	Day	28% 15% 31% 17% 7% 3	423
	11th to 20th	Day	22% 17% 31% 22% 7% 2	447
	21st to end	Day	21% 17% 32% 19% 9% 2	485
June	1st to 10th	Day	27% 12% 32% 20% 8% 1	450
	11th to 20th	Day	19% 14% 30% 24% 10% 3	450
	21st to end	Day	20% 13% 32% 21% 11% 2	450
July	1st to 10th	Day	11% 9% 30% 35% 11% 3	445
	11th to 20th	Day	14% 9% 35% 24% 14% 4	444
	21st to end	Day	14% 7% 34% 29% 13% 3	488
August	1st to 10th	Day	14% 9% 29% 30% 15% 4	446
	11th to 20th	Day	15% 7% 24% 31% 15% 8%	439
	21st to end	Day	17% 13% 26% 25% 12% 6%	495
September	1st to 10th	Day	16% 12% 30% 22% 14% 6%	450
	11th to 20th	Day	14% 12% 26% 22% 18% 8%	450
	21st to end	Day	19% 13% 30% 20% 12% 6%	450
October	1st to 10th	Day	25% 16% 24% 21% 11% 4	450
	11th to 20th	Day	30% 19% 29% 15% 7% 1	450
	21st to end	Day	31% 19% 27% 18% 5%	430
November	1st to 10th	Day	28% 15% 31% 18% 6% 1	343
	11th to 20th	Day	28% 26% 30% 12% 3	180
	21st to end	Day	29% 23% 33% 11% 3 1	180
December	1st to 10th	Day	34% 13% 37% 14% 2	180
	11th to 20th	Day	32% 25% 32% 10% 1 1	180
	21st to end	Day	34% 18% 35% 12% 1 1	198
January	1st to 10th	Night	27% 14% 35% 20% 3	760
	11th to 20th	Night	28% 18% 29% 20% 5%	760
	21st to end	Night	19% 14% 38% 23% 5%	836
February	1st to 10th	Night	21% 18% 36% 23% 3	760
	11th to 20th	Night	22% 19% 38% 18% 3	742
	21st to end	Night	24% 19% 29% 23% 4	592
March	1st to 10th	Night	24% 17% 33% 23% 3	720
	11th to 20th	Night	24% 17% 34% 19% 6%	720
	21st to end	Night	24% 17% 32% 20% 7%	792
April	1st to 10th	Night	28% 15% 28% 24% 4	720
	11th to 20th	Night	25% 18% 29% 21% 8%	711
	21st to end	Night	26% 16% 27% 24% 7% 1	598
May	1st to 10th	Night	25% 8% 29% 28% 9% 1	360
	11th to 20th	Night	24% 11% 27% 29% 9%	354
	21st to end	Night	15% 9% 36% 28% 12%	389
June	1st to 10th	Night	19% 8% 30% 35% 8%	360
	11th to 20th	Night	18% 7% 28% 34% 13% 1	360
	21st to end	Night	18% 7% 27% 33% 15%	360
July	1st to 10th	Night	9% 5% 29% 40% 17%	350
	11th to 20th	Night	13% 4 26% 40% 17%	348
	21st to end	Night	11% 5% 26% 42% 14% 2	394
August	1st to 10th	Night	11% 4 24% 39% 21% 1	411
	11th to 20th	Night	11% 4 19% 39% 24% 3	534
	21st to end	Night	14% 7% 27% 34% 16% 2	778
September	1st to 10th	Night	13% 8% 29% 29% 19% 1	720
	11th to 20th	Night	17% 7% 24% 31% 19% 3	720
	21st to end	Night	20% 9% 25% 25% 19% 2	720
October	1st to 10th	Night	24% 11% 26% 23% 15% 1	720
	11th to 20th	Night	27% 13% 30% 22% 7% 1	720
	21st to end	Night	28% 15% 28% 24% 4	792
November	1st to 10th	Night	26% 14% 26% 26% 7% 1	740
	11th to 20th	Night	27% 16% 32% 15% 10%	760
	21st to end	Night	30% 17% 27% 20% 5%	760
December	1st to 10th	Night	30% 17% 31% 19% 3	760
	11th to 20th	Night	28% 18% 29% 20% 5% 1	760
	21st to end	Night	35% 16% 30% 15% 4	836

Page generated at 2024-02-17 06:28:37. Version ac07

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