Koppany observing Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Koppany observing Site clear sky chart from 2005-11-06 to 2024-11-25.

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	12% 7% 3 7% 4 4 4 4 5% 7% 43%	101292
	Night	11% 7% 3 6% 4 3 4 3 5% 7% 47%	98266
Transparency	Day	39% 5% 13% 26% 16% 2	104969
	Night	36% 4 12% 27% 18% 3	102716
Seeing	Day	15% 9% 31% 29% 14% 3	15870
	Night	14% 9% 33% 34% 10% 1	25756

By Month

Percentage Cloud Cover SE (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	9% 13% 6% 14% 7% 5% 4 3 5% 8% 26%	2847
	11th to 20th	Day	10% 11% 4 11% 4 6% 7% 3 6% 7% 32%	2850
	21st to end	Day	9% 14% 6% 14% 6% 5% 5% 3 4 5% 29%	3135
February	1st to 10th	Day	10% 12% 5% 10% 6% 6% 4 3 5% 7% 32%	1710
	11th to 20th	Day	10% 11% 3 9% 4 4 5% 3 5% 6% 39%	1692
	21st to end	Day	11% 8% 4 8% 4 5% 5% 4 5% 7% 41%	1570
March	1st to 10th	Day	13% 9% 3 6% 4 3 3 2 3 5% 49%	3394
	11th to 20th	Day	11% 8% 2 6% 4 4 3 3 4 5% 50%	3480
	21st to end	Day	22% 12% 4 9% 4 4 5% 4 5% 7% 25%	3814
April	1st to 10th	Day	16% 8% 3 6% 3 4 3 3 4 6% 43%	2147
	11th to 20th	Day	16% 9% 2 6% 4 4 4 4 5% 7% 40%	2362
	21st to end	Day	20% 7% 2 6% 4 4 4 3 5% 7% 38%	2470
May	1st to 10th	Day	17% 8% 3 7% 5% 5% 4 4 6% 6% 35%	4082
	11th to 20th	Day	14% 8% 3 7% 4 4 3 3 4 6% 44%	4082
	21st to end	Day	14% 6% 2 7% 5% 4 5% 4 6% 7% 40%	4622
June	1st to 10th	Day	6% 5% 2 5% 4 4 4 4 7% 9% 49%	2660
	11th to 20th	Day	9% 6% 2 5% 5% 4 4 4 7% 8% 47%	2660
	21st to end	Day	7% 5% 2 6% 4 4 5% 3 5% 8% 50%	2660
July	1st to 10th	Day	13% 6% 2 5% 4 4 4 4 6% 8% 43%	4186
	11th to 20th	Day	7% 4 2 5% 4 4 4 4 5% 7% 54%	4120
	21st to end	Day	4 4 1 4 4 4 5% 4 7% 10% 53%	4465
August	1st to 10th	Day	7% 4 2 5% 5% 5% 5% 5% 7% 10% 46%	4104
	11th to 20th	Day	14% 6% 2 6% 5% 4 5% 4 6% 7% 41%	4041
	21st to end	Day	7% 4 2 6% 5% 4 5% 4 5% 8% 50%	4450
September	1st to 10th	Day	12% 5% 2 4 3 3 3 3 4 7% 53%	2209
	11th to 20th	Day	9% 6% 1 5% 3 3 4 3 5% 6% 54%	2090
	21st to end	Day	10% 4 2 5% 3 3 4 3 5% 5% 57%	2090
October	1st to 10th	Day	15% 6% 2 4 3 3 3 3 4 6% 52%	1944
	11th to 20th	Day	12% 5% 2 4 3 2 3 3 4 4 56%	1900
	21st to end	Day	13% 8% 2 6% 3 4 3 3 5% 6% 47%	2090
November	1st to 10th	Day	11% 6% 3 5% 3 3 4 3 4 5% 53%	1784
	11th to 20th	Day	10% 8% 2 9% 5% 4 5% 3 3 5% 47%	1732
	21st to end	Day	13% 9% 3 5% 3 3 3 3 5% 8% 44%	1552
December	1st to 10th	Day	9% 9% 3 6% 5% 4 4 4 6% 7% 44%	1520
	11th to 20th	Day	9% 10% 4 9% 5% 5% 4 4 6% 7% 37%	1918
	21st to end	Day	16% 10% 5% 15% 6% 4 4 4 5% 5% 26%	2860
January	1st to 10th	Night	8% 12% 4 18% 9% 5% 4 3 4 6% 27%	4108
	11th to 20th	Night	9% 11% 4 7% 5% 4 8% 4 8% 6% 35%	4120
	21st to end	Night	12% 13% 6% 11% 4 4 4 3 4 6% 32%	4532
February	1st to 10th	Night	11% 10% 4 9% 6% 4 4 3 5% 6% 38%	2470
	11th to 20th	Night	9% 9% 4 6% 5% 4 4 4 6% 7% 43%	2389
	21st to end	Night	9% 8% 3 6% 4 4 3 3 6% 5% 49%	1884
March	1st to 10th	Night	12% 7% 2 6% 3 3 3 3 3 5% 53%	3460
	11th to 20th	Night	11% 7% 2 4 2 3 3 2 4 6% 55%	3480
	21st to end	Night	18% 9% 3 8% 4 5% 4 4 5% 7% 33%	3817
April	1st to 10th	Night	12% 8% 2 6% 4 3 3 3 5% 6% 47%	2033
	11th to 20th	Night	12% 7% 2 6% 4 4 4 2 5% 6% 48%	1764
	21st to end	Night	17% 7% 2 4 4 4 3 3 3 6% 45%	1710
May	1st to 10th	Night	18% 7% 2 6% 3 3 3 3 5% 6% 44%	2823
	11th to 20th	Night	12% 5% 2 5% 3 3 4 3 4 7% 51%	2823
	21st to end	Night	16% 7% 2 6% 4 3 4 3 4 6% 44%	2941
June	1st to 10th	Night	5% 4 1 4 4 5% 5% 3 5% 9% 54%	1520
	11th to 20th	Night	9% 4 2 3 3 4 5% 4 6% 10% 50%	1520
	21st to end	Night	5% 2 2 5% 4 3 4 4 7% 8% 56%	1520
July	1st to 10th	Night	7% 5% 2 6% 3 2 4 3 6% 8% 53%	2778
	11th to 20th	Night	5% 2 1 3 3 3 3 3 6% 8% 64%	2850
	21st to end	Night	4 3 1 4 4 3 4 3 6% 9% 60%	3098
August	1st to 10th	Night	4 2 1 4 3 3 4 4 6% 11% 57%	2836
	11th to 20th	Night	12% 6% 2 4 4 3 4 3 5% 8% 49%	2798
	21st to end	Night	7% 4 2 4 4 4 4 3 5% 8% 56%	3214
September	1st to 10th	Night	8% 4 1 4 3 3 3 3 5% 6% 61%	1967
	11th to 20th	Night	9% 3 1 3 3 3 3 3 5% 8% 59%	2090
	21st to end	Night	11% 4 1 4 2 2 3 3 4 6% 60%	2090
October	1st to 10th	Night	13% 5% 2 3 3 3 5% 3 5% 6% 52%	2216
	11th to 20th	Night	13% 5% 2 4 3 3 2 2 4 5% 56%	2280
	21st to end	Night	14% 6% 2 5% 3 3 3 3 4 6% 52%	2508
November	1st to 10th	Night	10% 4 2 4 3 3 4 3 5% 7% 56%	2511
	11th to 20th	Night	10% 7% 2 6% 3 3 3 2 5% 6% 53%	2665
	21st to end	Night	12% 7% 2 5% 3 3 2 3 5% 6% 51%	2723
December	1st to 10th	Night	9% 8% 3 6% 6% 5% 4 3 5% 6% 45%	2660
	11th to 20th	Night	9% 9% 4 7% 4 3 3 3 5% 7% 47%	3279
	21st to end	Night	18% 13% 6% 12% 4 3 3 3 3 4 31%	4789

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	59% 3 13% 17% 7%	2848
	11th to 20th	Day	51% 3 15% 22% 9%	2850
	21st to end	Day	56% 5% 13% 17% 9%	3135
February	1st to 10th	Day	51% 5% 15% 18% 10% 1	1710
	11th to 20th	Day	44% 5% 12% 23% 14% 3	1701
	21st to end	Day	41% 5% 13% 24% 15% 3	1570
March	1st to 10th	Day	40% 3 9% 27% 18% 3	3394
	11th to 20th	Day	38% 4 10% 29% 17% 2	3480
	21st to end	Day	57% 5% 20% 14% 4 1	3814
April	1st to 10th	Day	43% 4 12% 26% 13% 2	2147
	11th to 20th	Day	44% 5% 13% 22% 13% 3	2362
	21st to end	Day	46% 5% 10% 25% 13% 1	2470
May	1st to 10th	Day	46% 5% 11% 22% 13% 2	4120
	11th to 20th	Day	42% 4 10% 25% 19% 1	4086
	21st to end	Day	41% 5% 13% 25% 15% 1	4635
June	1st to 10th	Day	31% 6% 17% 29% 15% 2	2660
	11th to 20th	Day	33% 6% 13% 31% 16% 1	2660
	21st to end	Day	32% 6% 14% 30% 15% 4	2660
July	1st to 10th	Day	37% 5% 15% 29% 13% 1	4122
	11th to 20th	Day	29% 5% 12% 32% 19% 3	4051
	21st to end	Day	22% 8% 18% 30% 20% 2	4325
August	1st to 10th	Day	30% 7% 16% 28% 17% 3	4090
	11th to 20th	Day	40% 5% 14% 26% 15% 1	4080
	21st to end	Day	32% 6% 14% 26% 16% 5%	4449
September	1st to 10th	Day	31% 4 11% 30% 19% 5%	2209
	11th to 20th	Day	31% 4 11% 34% 19% 1	2090
	21st to end	Day	30% 3 9% 32% 24% 1	2090
October	1st to 10th	Day	21% 2 7% 20% 46% 3	3230
	11th to 20th	Day	21% 2 12% 31% 27% 7%	3140
	21st to end	Day	36% 3 10% 26% 21% 3	3428
November	1st to 10th	Day	33% 3 15% 28% 19% 2	1784
	11th to 20th	Day	40% 4 12% 24% 19% 1	1732
	21st to end	Day	39% 3 13% 31% 13% 1	1552
December	1st to 10th	Day	39% 5% 16% 26% 13% 2	1520
	11th to 20th	Day	46% 3 17% 28% 6%	1915
	21st to end	Day	60% 5% 10% 18% 6%	2860
January	1st to 10th	Night	57% 4 11% 17% 10% 1	4108
	11th to 20th	Night	46% 4 14% 24% 10% 1	4120
	21st to end	Night	52% 5% 14% 19% 9% 1	4532
February	1st to 10th	Night	47% 4 13% 20% 13% 2	2470
	11th to 20th	Night	40% 5% 14% 23% 16% 3	2390
	21st to end	Night	36% 4 10% 25% 20% 4	1884
March	1st to 10th	Night	35% 4 9% 28% 22% 3	3460
	11th to 20th	Night	32% 3 9% 30% 20% 5%	3480
	21st to end	Night	50% 5% 21% 18% 5% 1	3817
April	1st to 10th	Night	37% 5% 11% 27% 18% 3	2033
	11th to 20th	Night	38% 4 11% 26% 18% 3	1764
	21st to end	Night	41% 4 13% 24% 18% 1	1710
May	1st to 10th	Night	41% 4 10% 24% 17% 2	2850
	11th to 20th	Night	34% 5% 12% 26% 22% 2	2824
	21st to end	Night	41% 5% 12% 21% 18% 3	2949
June	1st to 10th	Night	27% 6% 14% 34% 16% 4	1520
	11th to 20th	Night	27% 6% 15% 28% 20% 5%	1520
	21st to end	Night	24% 5% 15% 32% 20% 3	1520
July	1st to 10th	Night	29% 5% 15% 32% 17% 2	2733
	11th to 20th	Night	19% 4 15% 37% 21% 3	2796
	21st to end	Night	19% 7% 16% 33% 23% 2	2999
August	1st to 10th	Night	22% 5% 16% 35% 20% 2	2826
	11th to 20th	Night	33% 5% 14% 28% 19% 2	2825
	21st to end	Night	27% 5% 15% 27% 17% 8%	3214
September	1st to 10th	Night	25% 4 10% 30% 24% 6%	1967
	11th to 20th	Night	24% 4 12% 36% 20% 4	2090
	21st to end	Night	27% 3 8% 29% 28% 4	2090
October	1st to 10th	Night	20% 3 7% 17% 48% 5%	3697
	11th to 20th	Night	22% 2 8% 30% 30% 8%	3779
	21st to end	Night	34% 3 9% 31% 22% 1	4120
November	1st to 10th	Night	28% 4 15% 25% 24% 4	2511
	11th to 20th	Night	33% 3 12% 31% 19% 3	2665
	21st to end	Night	35% 3 12% 29% 19% 2	2723
December	1st to 10th	Night	39% 3 15% 29% 13% 1	2660
	11th to 20th	Night	37% 4 14% 35% 9%	3281
	21st to end	Night	58% 3 9% 21% 7% 1	4789

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	19% 13% 36% 22% 8% 2	270
	11th to 20th	Day	21% 11% 37% 21% 7% 1	270
	21st to end	Day	14% 13% 42% 21% 8% 2	297
February	1st to 10th	Day	16% 16% 45% 19% 3	270
	11th to 20th	Day	17% 16% 39% 21% 6% 1	270
	21st to end	Day	16% 20% 39% 22% 4	225
March	1st to 10th	Day	17% 14% 43% 20% 5%	270
	11th to 20th	Day	26% 12% 37% 18% 7% 1	270
	21st to end	Day	33% 16% 33% 15% 2 1	297
April	1st to 10th	Day	24% 16% 37% 19% 3	327
	11th to 20th	Day	21% 14% 37% 21% 7%	560
	21st to end	Day	23% 16% 30% 21% 8% 2	650
May	1st to 10th	Day	20% 13% 33% 24% 8% 1	653
	11th to 20th	Day	19% 8% 32% 27% 12% 2	675
	21st to end	Day	20% 7% 30% 26% 15% 2	734
June	1st to 10th	Day	6% 6% 23% 36% 24% 5%	680
	11th to 20th	Day	11% 6% 31% 34% 16% 3	680
	21st to end	Day	9% 8% 33% 35% 14% 3	680
July	1st to 10th	Day	10% 4 15% 33% 29% 9%	671
	11th to 20th	Day	7% 4 26% 35% 22% 6%	668
	21st to end	Day	7% 2 19% 42% 26% 4	739
August	1st to 10th	Day	8% 3 21% 43% 22% 4	676
	11th to 20th	Day	8% 4 20% 40% 26% 3	665
	21st to end	Day	10% 2 22% 38% 22% 5%	705
September	1st to 10th	Day	13% 4 28% 33% 18% 4	419
	11th to 20th	Day	7% 5% 32% 33% 19% 5%	300
	21st to end	Day	14% 9% 30% 30% 14% 3	300
October	1st to 10th	Day	19% 6% 29% 27% 13% 6%	300
	11th to 20th	Day	12% 17% 39% 22% 8% 2	300
	21st to end	Day	20% 14% 37% 18% 9% 2	330
November	1st to 10th	Day	19% 11% 36% 24% 8% 2	300
	11th to 20th	Day	16% 16% 39% 21% 7%	300
	21st to end	Day	22% 12% 33% 24% 8% 1	282
December	1st to 10th	Day	9% 11% 42% 30% 5% 2	270
	11th to 20th	Day	17% 13% 33% 27% 10% 1	270
	21st to end	Day	20% 15% 40% 22% 3	297
January	1st to 10th	Night	11% 12% 36% 33% 7% 1	950
	11th to 20th	Night	15% 12% 35% 30% 7%	950
	21st to end	Night	17% 8% 38% 30% 6%	1045
February	1st to 10th	Night	16% 11% 40% 29% 4	950
	11th to 20th	Night	12% 11% 42% 30% 5%	915
	21st to end	Night	15% 11% 43% 26% 5%	628
March	1st to 10th	Night	16% 12% 39% 28% 6%	600
	11th to 20th	Night	20% 8% 37% 28% 7%	570
	21st to end	Night	21% 13% 37% 23% 5%	627
April	1st to 10th	Night	17% 15% 41% 23% 5%	570
	11th to 20th	Night	15% 13% 38% 29% 4 1	563
	21st to end	Night	19% 11% 35% 28% 7% 1	570
May	1st to 10th	Night	18% 11% 32% 31% 8%	570
	11th to 20th	Night	15% 9% 32% 33% 10% 1	561
	21st to end	Night	17% 6% 31% 32% 13%	617
June	1st to 10th	Night	6% 4 27% 46% 16%	570
	11th to 20th	Night	10% 4 33% 41% 12% 1	570
	21st to end	Night	5% 4 33% 45% 13% 1	570
July	1st to 10th	Night	7% 2 17% 44% 28% 2	555
	11th to 20th	Night	4 2 20% 50% 24% 1	552
	21st to end	Night	4 1 18% 52% 25% 1	624
August	1st to 10th	Night	5% 2 19% 49% 23% 2	567
	11th to 20th	Night	7% 2 20% 47% 24%	564
	21st to end	Night	8% 3 23% 41% 23% 3	627
September	1st to 10th	Night	10% 3 23% 42% 20% 2	570
	11th to 20th	Night	11% 2 30% 40% 17% 1	570
	21st to end	Night	13% 5% 31% 35% 15% 1	570
October	1st to 10th	Night	15% 7% 32% 33% 11% 2	696
	11th to 20th	Night	16% 9% 36% 33% 7%	760
	21st to end	Night	19% 10% 31% 31% 9%	836
November	1st to 10th	Night	11% 11% 33% 36% 9% 1	951
	11th to 20th	Night	13% 13% 38% 29% 6%	1000
	21st to end	Night	16% 11% 34% 30% 9%	973
December	1st to 10th	Night	13% 11% 39% 31% 6%	950
	11th to 20th	Night	16% 9% 35% 33% 6%	950
	21st to end	Night	20% 12% 34% 29% 4	1045

Page generated at 2024-11-22 07:02:29. Version ac07

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