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 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	15% 10% 3 9% 5% 5% 5% 4 5% 7% 32%	144396
	Night	16% 12% 4 10% 5% 5% 4 4 5% 6% 30%	137458
Transparency	Day	35% 35% 8% 15% 7% 1	147876
	Night	37% 35% 7% 13% 7% 1	142067
Seeing	Day	24% 17% 30% 19% 8% 2	16652
	Night	23% 13% 29% 25% 9% 1	25693

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% 15% 6% 14% 7% 6% 5% 3 5% 5% 20%	4661
	11th to 20th	Day	12% 19% 7% 15% 7% 5% 4 3 5% 5% 18%	4650
	21st to end	Day	8% 15% 7% 15% 9% 8% 6% 4 4 5% 19%	5405
February	1st to 10th	Day	13% 13% 5% 14% 7% 6% 4 4 5% 5% 24%	1890
	11th to 20th	Day	12% 15% 5% 11% 6% 5% 4 4 5% 6% 27%	1843
	21st to end	Day	18% 13% 5% 9% 5% 5% 5% 4 5% 5% 25%	1711
March	1st to 10th	Day	20% 13% 4 11% 6% 4 4 3 4 6% 24%	4637
	11th to 20th	Day	13% 11% 4 10% 6% 5% 5% 4 5% 7% 28%	5090
	21st to end	Day	17% 12% 3 8% 5% 4 3 3 4 5% 37%	5859
April	1st to 10th	Day	21% 13% 3 7% 4 4 4 3 4 5% 32%	2520
	11th to 20th	Day	22% 10% 3 7% 4 4 3 3 5% 4 35%	2494
	21st to end	Day	21% 10% 3 8% 5% 4 4 3 4 5% 33%	2681
May	1st to 10th	Day	20% 9% 3 8% 5% 4 5% 4 6% 7% 29%	8237
	11th to 20th	Day	15% 8% 3 8% 5% 5% 5% 4 6% 8% 34%	8221
	21st to end	Day	19% 9% 3 7% 4 4 4 4 5% 6% 35%	9060
June	1st to 10th	Day	19% 8% 3 8% 5% 5% 5% 4 6% 7% 31%	2940
	11th to 20th	Day	15% 6% 3 6% 5% 5% 5% 4 6% 7% 39%	2940
	21st to end	Day	16% 7% 2 7% 5% 5% 5% 4 7% 8% 32%	2940
July	1st to 10th	Day	12% 6% 2 7% 5% 5% 5% 5% 7% 10% 37%	8280
	11th to 20th	Day	9% 4 2 6% 4 4 4 4 6% 9% 48%	8280
	21st to end	Day	10% 5% 2 6% 4 4 5% 4 7% 10% 41%	8993
August	1st to 10th	Day	13% 6% 3 8% 5% 5% 5% 4 7% 7% 36%	4585
	11th to 20th	Day	15% 7% 3 6% 4 4 5% 4 7% 8% 38%	4208
	21st to end	Day	12% 5% 3 6% 4 4 5% 4 7% 10% 40%	4312
September	1st to 10th	Day	13% 6% 2 5% 4 4 5% 4 6% 8% 42%	2400
	11th to 20th	Day	11% 5% 3 6% 4 4 4 4 5% 7% 47%	2400
	21st to end	Day	16% 7% 2 7% 3 4 5% 4 5% 8% 39%	2124
October	1st to 10th	Day	20% 6% 3 7% 5% 4 4 3 5% 6% 36%	2000
	11th to 20th	Day	21% 9% 3 8% 5% 5% 5% 4 5% 7% 29%	2000
	21st to end	Day	25% 11% 3 7% 5% 5% 4 4 4 6% 27%	2055
November	1st to 10th	Day	16% 10% 3 6% 6% 5% 5% 4 6% 6% 33%	1826
	11th to 20th	Day	18% 13% 4 9% 5% 5% 5% 4 5% 6% 25%	1680
	21st to end	Day	21% 15% 5% 10% 6% 5% 5% 3 4 6% 19%	1680
December	1st to 10th	Day	21% 21% 5% 11% 5% 5% 5% 4 4 5% 13%	2680
	11th to 20th	Day	17% 18% 5% 12% 6% 5% 3 3 4 5% 24%	3066
	21st to end	Day	23% 17% 5% 13% 5% 4 5% 3 3 4 19%	4048
January	1st to 10th	Night	13% 18% 8% 16% 6% 5% 4 3 4 5% 18%	8234
	11th to 20th	Night	12% 18% 6% 15% 8% 6% 5% 3 4 5% 19%	8235
	21st to end	Night	10% 17% 6% 12% 8% 7% 5% 4 5% 5% 21%	8762
February	1st to 10th	Night	12% 14% 5% 13% 7% 6% 5% 4 5% 6% 24%	2730
	11th to 20th	Night	12% 14% 5% 12% 7% 4 4 4 4 5% 28%	2663
	21st to end	Night	15% 13% 5% 10% 6% 4 6% 3 5% 6% 26%	2094
March	1st to 10th	Night	20% 16% 4 9% 5% 4 3 3 4 4 28%	5419
	11th to 20th	Night	12% 12% 4 10% 5% 5% 5% 4 6% 8% 28%	5089
	21st to end	Night	18% 11% 3 9% 5% 5% 3 3 4 6% 33%	5314
April	1st to 10th	Night	20% 11% 3 8% 4 4 3 3 5% 6% 32%	2100
	11th to 20th	Night	18% 10% 3 7% 5% 4 5% 3 4 6% 34%	2075
	21st to end	Night	20% 9% 4 8% 5% 4 3 3 4 5% 35%	1957
May	1st to 10th	Night	20% 9% 4 8% 5% 5% 5% 5% 6% 7% 26%	4660
	11th to 20th	Night	15% 8% 3 7% 5% 4 5% 3 5% 7% 38%	4639
	21st to end	Night	19% 7% 3 7% 4 4 5% 4 6% 7% 34%	5114
June	1st to 10th	Night	16% 7% 3 7% 5% 4 5% 5% 6% 8% 34%	1680
	11th to 20th	Night	13% 6% 2 6% 5% 3 4 4 5% 7% 43%	1680
	21st to end	Night	16% 7% 3 5% 5% 4 4 4 8% 8% 36%	1680
July	1st to 10th	Night	11% 6% 3 8% 6% 5% 5% 5% 6% 9% 36%	4680
	11th to 20th	Night	10% 4 3 7% 4 4 5% 4 5% 8% 46%	4680
	21st to end	Night	11% 6% 2 7% 5% 5% 5% 4 6% 7% 42%	5084
August	1st to 10th	Night	11% 7% 3 7% 5% 4 4 5% 6% 9% 39%	2767
	11th to 20th	Night	14% 7% 3 7% 4 4 5% 3 6% 7% 42%	2911
	21st to end	Night	14% 6% 2 6% 4 4 5% 5% 6% 8% 41%	3571
September	1st to 10th	Night	11% 5% 2 6% 5% 4 4 3 4 8% 47%	2000
	11th to 20th	Night	13% 5% 2 5% 3 4 3 3 5% 6% 50%	2000
	21st to end	Night	17% 7% 2 7% 4 4 3 3 5% 6% 43%	2271
October	1st to 10th	Night	16% 8% 3 6% 4 5% 4 3 5% 5% 41%	2400
	11th to 20th	Night	20% 8% 3 8% 5% 6% 5% 3 5% 7% 31%	2400
	21st to end	Night	21% 11% 3 8% 5% 4 4 3 5% 6% 28%	2783
November	1st to 10th	Night	19% 11% 3 8% 5% 4 4 3 5% 6% 32%	2688
	11th to 20th	Night	19% 12% 4 8% 5% 5% 5% 4 5% 5% 27%	2940
	21st to end	Night	21% 14% 4 10% 6% 5% 4 4 5% 6% 21%	2940
December	1st to 10th	Night	19% 18% 5% 12% 6% 5% 5% 4 5% 5% 15%	4720
	11th to 20th	Night	21% 15% 5% 11% 6% 4 4 3 3 5% 23%	5348
	21st to end	Night	26% 18% 4 11% 4 4 4 3 3 4 20%	7150

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	53% 23% 8% 11% 4	4662
	11th to 20th	Day	57% 22% 6% 7% 7%	4680
	21st to end	Day	55% 24% 6% 8% 6% 1	5405
February	1st to 10th	Day	27% 59% 3 7% 3 1	1890
	11th to 20th	Day	25% 58% 4 8% 4	1852
	21st to end	Day	26% 59% 4 4 5% 2	1711
March	1st to 10th	Day	47% 29% 5% 7% 9% 3	4640
	11th to 20th	Day	39% 30% 12% 10% 7% 1	5090
	21st to end	Day	38% 28% 5% 14% 14% 1	5859
April	1st to 10th	Day	24% 59% 4 6% 6% 1	2520
	11th to 20th	Day	24% 59% 2 9% 5% 1	2494
	21st to end	Day	23% 59% 3 7% 7% 1	2681
May	1st to 10th	Day	42% 25% 7% 17% 8% 1	8249
	11th to 20th	Day	39% 26% 11% 18% 7%	8225
	21st to end	Day	42% 24% 8% 18% 9%	9061
June	1st to 10th	Day	21% 59% 4 10% 6% 1	2940
	11th to 20th	Day	20% 60% 5% 10% 5% 1	2940
	21st to end	Day	19% 59% 5% 11% 5%	2940
July	1st to 10th	Day	34% 22% 13% 20% 10%	8210
	11th to 20th	Day	25% 22% 11% 31% 9% 1	8205
	21st to end	Day	29% 22% 14% 28% 7%	8795
August	1st to 10th	Day	31% 36% 11% 15% 6%	4571
	11th to 20th	Day	30% 37% 9% 18% 5%	4247
	21st to end	Day	24% 38% 12% 18% 7%	4312
September	1st to 10th	Day	17% 59% 7% 12% 5%	2400
	11th to 20th	Day	13% 58% 6% 17% 6%	2400
	21st to end	Day	16% 58% 6% 12% 8%	2124
October	1st to 10th	Day	31% 37% 7% 21% 4	3260
	11th to 20th	Day	27% 38% 9% 18% 7%	3240
	21st to end	Day	33% 37% 13% 14% 3	3293
November	1st to 10th	Day	30% 54% 5% 8% 2	1826
	11th to 20th	Day	27% 55% 6% 9% 3	1680
	21st to end	Day	32% 56% 5% 3 4	1680
December	1st to 10th	Day	50% 36% 6% 7% 1	2680
	11th to 20th	Day	47% 32% 6% 9% 6%	3066
	21st to end	Day	52% 27% 4 13% 4	4048
January	1st to 10th	Night	56% 22% 8% 10% 4	8234
	11th to 20th	Night	56% 22% 8% 9% 5%	8280
	21st to end	Night	53% 23% 6% 8% 9%	8762
February	1st to 10th	Night	24% 59% 5% 8% 3	2730
	11th to 20th	Night	25% 58% 3 10% 4	2665
	21st to end	Night	24% 59% 3 7% 5%	2094
March	1st to 10th	Night	46% 29% 5% 9% 9% 3	5429
	11th to 20th	Night	38% 32% 12% 11% 6% 2	5090
	21st to end	Night	39% 29% 7% 15% 8% 2	5314
April	1st to 10th	Night	23% 59% 4 8% 5% 1	2100
	11th to 20th	Night	22% 59% 3 9% 7%	2075
	21st to end	Night	20% 59% 4 8% 8% 1	1957
May	1st to 10th	Night	44% 26% 8% 16% 5% 1	4666
	11th to 20th	Night	37% 26% 10% 17% 10%	4640
	21st to end	Night	40% 25% 8% 16% 10%	5115
June	1st to 10th	Night	18% 59% 4 11% 7% 1	1680
	11th to 20th	Night	16% 60% 4 11% 8% 1	1680
	21st to end	Night	19% 58% 4 11% 6%	1680
July	1st to 10th	Night	36% 23% 13% 17% 10% 1	4640
	11th to 20th	Night	27% 23% 11% 27% 11%	4632
	21st to end	Night	32% 23% 10% 26% 10%	4967
August	1st to 10th	Night	28% 37% 9% 18% 8%	2757
	11th to 20th	Night	30% 38% 9% 19% 4	2938
	21st to end	Night	26% 38% 9% 17% 8% 2	3571
September	1st to 10th	Night	14% 59% 7% 15% 6%	2000
	11th to 20th	Night	14% 58% 6% 17% 6% 1	2000
	21st to end	Night	16% 58% 5% 13% 8%	2271
October	1st to 10th	Night	23% 36% 9% 22% 9%	3920
	11th to 20th	Night	27% 38% 10% 18% 7%	3899
	21st to end	Night	32% 36% 12% 13% 6%	4495
November	1st to 10th	Night	28% 54% 8% 8% 3	2688
	11th to 20th	Night	27% 55% 5% 10% 3	2940
	21st to end	Night	30% 55% 6% 6% 3	2940
December	1st to 10th	Night	46% 37% 8% 8% 2	4720
	11th to 20th	Night	47% 30% 4 9% 9%	5348
	21st to end	Night	52% 26% 3 9% 9%	7150

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	22% 24% 35% 15% 4	220
	11th to 20th	Day	28% 19% 37% 12% 3 1	220
	21st to end	Day	21% 21% 35% 18% 4	294
February	1st to 10th	Day	29% 24% 32% 12% 3	330
	11th to 20th	Day	27% 30% 35% 7%	330
	21st to end	Day	32% 22% 31% 13% 1	427
March	1st to 10th	Day	29% 20% 34% 13% 4	540
	11th to 20th	Day	30% 21% 31% 13% 3 1	540
	21st to end	Day	32% 21% 29% 14% 4 1	594
April	1st to 10th	Day	35% 23% 24% 14% 4	540
	11th to 20th	Day	36% 19% 22% 13% 8% 1	532
	21st to end	Day	30% 23% 29% 11% 5% 1	540
May	1st to 10th	Day	28% 17% 31% 15% 6% 2	543
	11th to 20th	Day	21% 18% 31% 21% 7% 2	567
	21st to end	Day	24% 17% 30% 18% 8% 1	617
June	1st to 10th	Day	26% 14% 30% 21% 8% 2	570
	11th to 20th	Day	20% 15% 32% 22% 9% 2	570
	21st to end	Day	21% 14% 33% 20% 9% 2	570
July	1st to 10th	Day	11% 10% 34% 33% 10% 2	565
	11th to 20th	Day	14% 11% 35% 24% 12% 3	564
	21st to end	Day	14% 10% 33% 28% 13% 3	620
August	1st to 10th	Day	16% 8% 30% 30% 13% 3	566
	11th to 20th	Day	16% 8% 26% 29% 15% 7%	535
	21st to end	Day	17% 12% 27% 26% 12% 5%	583
September	1st to 10th	Day	17% 11% 30% 22% 14% 6%	530
	11th to 20th	Day	12% 10% 24% 23% 21% 10%	530
	21st to end	Day	19% 13% 29% 21% 12% 5%	530
October	1st to 10th	Day	24% 17% 24% 22% 12% 3	530
	11th to 20th	Day	28% 19% 31% 14% 7% 1	530
	21st to end	Day	31% 17% 29% 18% 4	503
November	1st to 10th	Day	30% 18% 30% 17% 5% 1	400
	11th to 20th	Day	25% 26% 32% 13% 4	220
	21st to end	Day	34% 22% 32% 10% 2 1	220
December	1st to 10th	Day	33% 15% 36% 15% 1	220
	11th to 20th	Day	32% 24% 34% 8% 1	220
	21st to end	Day	33% 18% 34% 13% 2	242
January	1st to 10th	Night	27% 15% 36% 20% 3	840
	11th to 20th	Night	29% 18% 28% 19% 5%	840
	21st to end	Night	19% 15% 37% 23% 5%	924
February	1st to 10th	Night	19% 19% 35% 24% 3	840
	11th to 20th	Night	22% 19% 38% 18% 3	823
	21st to end	Night	23% 19% 30% 23% 4	692
March	1st to 10th	Night	26% 17% 33% 21% 3	840
	11th to 20th	Night	25% 19% 33% 19% 5%	840
	21st to end	Night	25% 17% 33% 19% 6%	924
April	1st to 10th	Night	29% 15% 28% 23% 4	840
	11th to 20th	Night	25% 18% 29% 20% 7%	831
	21st to end	Night	26% 16% 28% 23% 6%	697
May	1st to 10th	Night	24% 10% 28% 27% 9% 1	420
	11th to 20th	Night	22% 11% 30% 29% 8%	414
	21st to end	Night	17% 10% 36% 26% 11%	455
June	1st to 10th	Night	19% 8% 29% 36% 8%	420
	11th to 20th	Night	17% 7% 28% 35% 12% 1	420
	21st to end	Night	20% 6% 28% 33% 13%	420
July	1st to 10th	Night	10% 5% 30% 41% 15%	410
	11th to 20th	Night	13% 5% 25% 41% 15%	408
	21st to end	Night	12% 5% 25% 41% 15% 2	460
August	1st to 10th	Night	12% 4 23% 39% 21% 1	480
	11th to 20th	Night	11% 5% 20% 38% 24% 2	606
	21st to end	Night	14% 7% 26% 35% 17% 2	865
September	1st to 10th	Night	13% 8% 29% 30% 19% 1	800
	11th to 20th	Night	16% 6% 22% 30% 22% 3	800
	21st to end	Night	21% 9% 25% 26% 18% 2	800
October	1st to 10th	Night	23% 11% 26% 24% 16% 1	800
	11th to 20th	Night	25% 14% 31% 22% 7% 1	800
	21st to end	Night	27% 15% 29% 24% 4	880
November	1st to 10th	Night	27% 15% 26% 25% 6% 1	820
	11th to 20th	Night	27% 16% 33% 15% 9%	840
	21st to end	Night	31% 17% 27% 20% 5%	840
December	1st to 10th	Night	28% 18% 30% 19% 4	840
	11th to 20th	Night	28% 18% 29% 19% 5% 1	840
	21st to end	Night	36% 16% 29% 16% 4	924

Page generated at 2026-08-12 03:37:14. Version ac07

Copyright © 2026 Attilla Danko.