Neuenschwander Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Neuenschwander Observatory clear sky chart from 2005-11-06 to 2024-12-02.

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	14% 10% 4 8% 5% 5% 5% 4 6% 7% 34%	101406
	Night	15% 11% 4 8% 5% 4 4 3 5% 6% 33%	98252
Transparency	Day	47% 6% 12% 21% 13% 1	105019
	Night	49% 6% 11% 20% 13% 1	102779
Seeing	Day	17% 10% 27% 24% 15% 6%	15808
	Night	19% 8% 29% 30% 13% 1	25669

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	16% 19% 7% 12% 6% 4 5% 3 4 5% 19%	2527
	11th to 20th	Day	14% 18% 7% 13% 7% 7% 6% 6% 7% 4 11%	2530
	21st to end	Day	26% 20% 8% 14% 5% 4 3 2 3 3 11%	2846
February	1st to 10th	Day	15% 14% 5% 12% 9% 6% 4 4 5% 5% 21%	1786
	11th to 20th	Day	15% 11% 5% 14% 8% 5% 5% 4 5% 6% 23%	1848
	21st to end	Day	16% 16% 5% 11% 6% 5% 4 3 5% 6% 23%	1570
March	1st to 10th	Day	18% 14% 5% 9% 5% 5% 4 3 5% 7% 27%	3120
	11th to 20th	Day	12% 9% 5% 9% 6% 5% 5% 4 7% 7% 30%	3411
	21st to end	Day	19% 13% 6% 10% 6% 5% 5% 4 5% 6% 22%	3907
April	1st to 10th	Day	18% 13% 3 7% 5% 4 5% 4 5% 6% 30%	2280
	11th to 20th	Day	17% 10% 3 6% 5% 4 4 4 5% 6% 36%	2304
	21st to end	Day	18% 10% 3 7% 4 4 4 3 5% 7% 34%	2470
May	1st to 10th	Day	18% 8% 3 7% 5% 4 5% 4 6% 8% 32%	4082
	11th to 20th	Day	14% 8% 2 6% 4 5% 5% 4 5% 9% 37%	4081
	21st to end	Day	10% 6% 2 6% 4 4 5% 3 6% 9% 44%	4686
June	1st to 10th	Day	10% 6% 3 6% 5% 5% 5% 5% 6% 9% 42%	2660
	11th to 20th	Day	10% 5% 1 6% 5% 5% 5% 4 7% 8% 44%	2660
	21st to end	Day	10% 6% 2 7% 5% 5% 5% 4 7% 8% 39%	2660
July	1st to 10th	Day	11% 7% 3 7% 5% 5% 5% 4 6% 10% 37%	4440
	11th to 20th	Day	8% 4 1 4 4 4 5% 4 6% 11% 48%	4440
	21st to end	Day	6% 6% 2 8% 5% 5% 6% 4 7% 9% 43%	4735
August	1st to 10th	Day	10% 6% 2 6% 4 4 5% 4 6% 9% 45%	4104
	11th to 20th	Day	10% 6% 2 6% 4 4 5% 4 6% 8% 45%	4044
	21st to end	Day	7% 5% 2 6% 4 4 5% 4 6% 10% 46%	4220
September	1st to 10th	Day	11% 6% 3 5% 5% 4 5% 4 5% 8% 44%	2228
	11th to 20th	Day	11% 3 2 5% 3 4 5% 4 7% 9% 47%	2090
	21st to end	Day	13% 7% 3 7% 4 4 4 3 6% 8% 41%	2090
October	1st to 10th	Day	13% 6% 2 7% 5% 4 4 3 6% 7% 43%	2090
	11th to 20th	Day	18% 9% 2 8% 5% 5% 4 4 6% 6% 33%	1886
	21st to end	Day	21% 11% 3 7% 5% 5% 6% 4 5% 7% 27%	1881
November	1st to 10th	Day	12% 10% 4 6% 5% 3 5% 4 5% 7% 38%	1762
	11th to 20th	Day	16% 17% 4 11% 6% 4 4 3 4 5% 26%	1800
	21st to end	Day	21% 14% 6% 10% 5% 5% 3 3 4 5% 24%	1800
December	1st to 10th	Day	15% 19% 8% 12% 6% 4 3 3 5% 5% 21%	1667
	11th to 20th	Day	13% 17% 7% 14% 6% 5% 4 4 4 7% 18%	1918
	21st to end	Day	22% 21% 8% 14% 6% 5% 3 2 4 4 11%	2783
January	1st to 10th	Night	17% 18% 9% 11% 6% 5% 4 3 4 5% 19%	4428
	11th to 20th	Night	15% 19% 8% 16% 6% 4 5% 5% 6% 4 12%	4440
	21st to end	Night	26% 18% 8% 15% 6% 4 3 3 3 4 11%	4816
February	1st to 10th	Night	17% 16% 4 10% 8% 5% 4 4 4 5% 22%	2392
	11th to 20th	Night	14% 14% 4 11% 7% 6% 4 3 4 7% 25%	2218
	21st to end	Night	19% 13% 5% 10% 6% 5% 4 3 5% 4 27%	1884
March	1st to 10th	Night	16% 12% 5% 8% 5% 4 3 3 4 6% 34%	3733
	11th to 20th	Night	10% 8% 4 7% 5% 5% 5% 4 5% 7% 42%	3549
	21st to end	Night	19% 10% 5% 10% 5% 4 4 3 4 6% 30%	3740
April	1st to 10th	Night	16% 9% 3 6% 5% 4 5% 3 5% 7% 36%	1900
	11th to 20th	Night	19% 8% 2 6% 5% 4 4 4 4 6% 36%	1823
	21st to end	Night	17% 8% 4 7% 4 3 5% 4 5% 7% 37%	1710
May	1st to 10th	Night	15% 8% 3 8% 4 5% 5% 4 6% 8% 33%	2813
	11th to 20th	Night	18% 8% 2 5% 3 3 4 2 5% 7% 42%	2812
	21st to end	Night	13% 5% 2 7% 5% 4 4 3 6% 8% 43%	2874
June	1st to 10th	Night	10% 4 2 5% 4 4 4 4 7% 9% 48%	1520
	11th to 20th	Night	9% 5% 3 6% 5% 4 4 5% 7% 8% 44%	1520
	21st to end	Night	9% 4 2 5% 5% 5% 5% 5% 7% 8% 44%	1520
July	1st to 10th	Night	9% 5% 2 6% 5% 4 5% 4 7% 9% 45%	2530
	11th to 20th	Night	7% 4 2 5% 3 3 4 3 6% 8% 55%	2530
	21st to end	Night	6% 5% 2 5% 4 4 5% 5% 8% 10% 45%	2810
August	1st to 10th	Night	10% 6% 2 5% 4 4 4 4 7% 8% 45%	2825
	11th to 20th	Night	9% 5% 2 5% 4 5% 4 4 6% 9% 48%	2785
	21st to end	Night	9% 6% 2 6% 4 4 4 3 6% 7% 47%	3433
September	1st to 10th	Night	10% 6% 2 5% 4 3 4 3 6% 6% 51%	1932
	11th to 20th	Night	9% 4 2 5% 4 3 4 3 4 8% 54%	2090
	21st to end	Night	14% 7% 2 6% 4 3 5% 3 4 7% 45%	2090
October	1st to 10th	Night	13% 7% 2 6% 3 4 3 3 5% 7% 47%	2090
	11th to 20th	Night	17% 11% 4 7% 4 4 4 3 5% 6% 36%	2287
	21st to end	Night	22% 9% 3 7% 5% 4 4 3 5% 6% 34%	2717
November	1st to 10th	Night	14% 10% 3 7% 5% 4 4 2 5% 6% 39%	2536
	11th to 20th	Night	15% 15% 3 8% 5% 4 4 4 6% 7% 28%	2600
	21st to end	Night	18% 18% 4 8% 5% 4 4 3 4 7% 25%	2600
December	1st to 10th	Night	17% 19% 6% 11% 6% 5% 5% 3 4 5% 19%	2542
	11th to 20th	Night	16% 18% 7% 12% 6% 4 4 3 5% 5% 20%	3279
	21st to end	Night	26% 20% 7% 10% 5% 4 4 3 4 5% 12%	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	67% 7% 10% 13% 3	2528
	11th to 20th	Day	72% 4 12% 8% 4	2530
	21st to end	Day	81% 3 6% 8% 2	2846
February	1st to 10th	Day	65% 5% 10% 11% 7% 1	1786
	11th to 20th	Day	61% 6% 10% 14% 8% 1	1858
	21st to end	Day	62% 5% 11% 14% 6% 1	1570
March	1st to 10th	Day	57% 5% 11% 19% 7%	3120
	11th to 20th	Day	50% 6% 15% 21% 7% 1	3411
	21st to end	Day	61% 7% 10% 17% 5%	3907
April	1st to 10th	Day	54% 6% 10% 20% 10%	2280
	11th to 20th	Day	47% 6% 11% 21% 12% 2	2304
	21st to end	Day	49% 5% 13% 17% 14% 2	2470
May	1st to 10th	Day	48% 7% 12% 22% 11%	4120
	11th to 20th	Day	42% 7% 15% 25% 10% 1	4085
	21st to end	Day	36% 7% 11% 20% 23% 2	4699
June	1st to 10th	Day	37% 8% 12% 26% 16% 2	2660
	11th to 20th	Day	35% 7% 13% 25% 18% 2	2660
	21st to end	Day	39% 8% 14% 21% 15% 2	2660
July	1st to 10th	Day	42% 6% 13% 20% 16% 3	4371
	11th to 20th	Day	28% 6% 14% 34% 16% 2	4365
	21st to end	Day	35% 8% 15% 18% 21% 2	4585
August	1st to 10th	Day	34% 8% 15% 26% 16% 1	4091
	11th to 20th	Day	36% 8% 11% 29% 16% 1	4083
	21st to end	Day	33% 6% 13% 30% 15% 2	4219
September	1st to 10th	Day	37% 7% 15% 21% 17% 3	2228
	11th to 20th	Day	32% 6% 12% 29% 20% 1	2090
	21st to end	Day	41% 4 12% 24% 18% 1	2090
October	1st to 10th	Day	29% 4 9% 38% 18% 1	3480
	11th to 20th	Day	40% 5% 11% 24% 21%	3115
	21st to end	Day	47% 5% 11% 24% 11% 2	3081
November	1st to 10th	Day	44% 6% 12% 24% 13% 1	1762
	11th to 20th	Day	60% 4 10% 17% 8% 1	1800
	21st to end	Day	64% 5% 11% 15% 5%	1800
December	1st to 10th	Day	65% 5% 12% 14% 4	1667
	11th to 20th	Day	66% 5% 14% 12% 2	1915
	21st to end	Day	78% 5% 7% 6% 4	2783
January	1st to 10th	Night	67% 6% 9% 12% 5% 1	4428
	11th to 20th	Night	73% 5% 10% 8% 3	4440
	21st to end	Night	78% 4 7% 7% 2 1	4816
February	1st to 10th	Night	64% 6% 10% 12% 6% 1	2392
	11th to 20th	Night	59% 5% 9% 19% 8% 1	2219
	21st to end	Night	60% 4 11% 16% 7% 2	1884
March	1st to 10th	Night	51% 4 13% 24% 8% 1	3733
	11th to 20th	Night	39% 6% 14% 22% 16% 2	3549
	21st to end	Night	55% 6% 12% 18% 8% 1	3740
April	1st to 10th	Night	48% 5% 12% 20% 14% 1	1900
	11th to 20th	Night	48% 6% 8% 18% 18% 2	1823
	21st to end	Night	46% 5% 12% 19% 15% 3	1710
May	1st to 10th	Night	47% 7% 11% 22% 12% 1	2840
	11th to 20th	Night	42% 6% 11% 25% 15% 1	2813
	21st to end	Night	38% 7% 12% 21% 20% 2	2882
June	1st to 10th	Night	32% 6% 13% 28% 18% 3	1520
	11th to 20th	Night	36% 8% 14% 22% 19% 2	1520
	21st to end	Night	34% 9% 17% 21% 17% 3	1520
July	1st to 10th	Night	34% 6% 14% 25% 14% 6%	2490
	11th to 20th	Night	26% 6% 14% 27% 24% 3	2482
	21st to end	Night	32% 7% 17% 17% 23% 4	2720
August	1st to 10th	Night	33% 7% 14% 30% 15% 1	2814
	11th to 20th	Night	32% 6% 13% 31% 16% 1	2812
	21st to end	Night	35% 6% 10% 29% 18% 2	3433
September	1st to 10th	Night	33% 6% 11% 25% 21% 4	1932
	11th to 20th	Night	29% 5% 8% 32% 24% 2	2090
	21st to end	Night	39% 5% 10% 28% 16% 1	2090
October	1st to 10th	Night	25% 5% 8% 35% 27% 1	3480
	11th to 20th	Night	41% 4 10% 23% 22%	3797
	21st to end	Night	39% 4 9% 30% 17% 1	4467
November	1st to 10th	Night	46% 5% 10% 24% 15% 1	2536
	11th to 20th	Night	54% 6% 13% 17% 8% 2	2600
	21st to end	Night	60% 5% 12% 19% 5%	2600
December	1st to 10th	Night	68% 5% 9% 12% 5%	2542
	11th to 20th	Night	67% 5% 11% 12% 5% 1	3281
	21st to end	Night	75% 5% 11% 7% 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	21% 19% 32% 19% 8% 1	270
	11th to 20th	Day	23% 14% 40% 17% 5% 1	270
	21st to end	Day	29% 13% 30% 22% 7%	297
February	1st to 10th	Day	23% 14% 37% 19% 5% 2	270
	11th to 20th	Day	26% 16% 31% 22% 4	270
	21st to end	Day	22% 24% 35% 15% 4	225
March	1st to 10th	Day	17% 21% 39% 18% 4	270
	11th to 20th	Day	22% 15% 32% 22% 7% 1	417
	21st to end	Day	31% 13% 28% 19% 7% 1	506
April	1st to 10th	Day	23% 12% 34% 23% 7% 1	460
	11th to 20th	Day	26% 15% 31% 15% 9% 4	452
	21st to end	Day	25% 13% 31% 20% 9% 3	460
May	1st to 10th	Day	20% 13% 30% 23% 10% 3	463
	11th to 20th	Day	21% 10% 24% 25% 14% 6%	487
	21st to end	Day	15% 7% 24% 27% 19% 8%	648
June	1st to 10th	Day	12% 7% 26% 31% 18% 6%	680
	11th to 20th	Day	13% 6% 27% 29% 20% 5%	680
	21st to end	Day	13% 7% 29% 29% 16% 6%	680
July	1st to 10th	Day	8% 4 20% 30% 23% 15%	671
	11th to 20th	Day	11% 4 22% 28% 23% 12%	668
	21st to end	Day	7% 3 21% 32% 26% 11%	697
August	1st to 10th	Day	7% 4 18% 28% 25% 18%	486
	11th to 20th	Day	13% 5% 18% 27% 27% 11%	479
	21st to end	Day	10% 4 17% 28% 28% 12%	539
September	1st to 10th	Day	13% 5% 21% 27% 22% 12%	490
	11th to 20th	Day	8% 3 17% 24% 31% 16%	490
	21st to end	Day	15% 11% 20% 26% 19% 8%	490
October	1st to 10th	Day	16% 6% 29% 27% 16% 7%	490
	11th to 20th	Day	20% 15% 29% 28% 7% 1	433
	21st to end	Day	27% 14% 36% 16% 6% 1	330
November	1st to 10th	Day	16% 15% 35% 22% 10% 2	300
	11th to 20th	Day	25% 21% 30% 16% 7%	300
	21st to end	Day	30% 14% 37% 15% 4	300
December	1st to 10th	Day	23% 22% 34% 13% 6% 1	273
	11th to 20th	Day	21% 14% 41% 19% 4	270
	21st to end	Day	25% 23% 34% 16% 2	297
January	1st to 10th	Night	22% 14% 35% 23% 6%	950
	11th to 20th	Night	26% 13% 34% 22% 5% 1	950
	21st to end	Night	22% 9% 36% 28% 5%	1003
February	1st to 10th	Night	26% 9% 38% 23% 4	760
	11th to 20th	Night	21% 14% 36% 26% 3	743
	21st to end	Night	25% 11% 38% 22% 3	628
March	1st to 10th	Night	20% 13% 33% 26% 7% 1	760
	11th to 20th	Night	19% 9% 38% 26% 8% 1	760
	21st to end	Night	24% 10% 32% 27% 7%	797
April	1st to 10th	Night	19% 11% 35% 28% 7% 1	570
	11th to 20th	Night	24% 9% 33% 28% 6% 1	563
	21st to end	Night	22% 6% 34% 29% 9% 1	570
May	1st to 10th	Night	22% 5% 31% 32% 9% 1	570
	11th to 20th	Night	24% 4 26% 30% 16%	561
	21st to end	Night	13% 5% 24% 38% 18% 2	617
June	1st to 10th	Night	11% 4 23% 45% 16% 1	570
	11th to 20th	Night	10% 4 25% 42% 17% 1	570
	21st to end	Night	10% 2 23% 41% 22% 2	570
July	1st to 10th	Night	8% 3 16% 40% 27% 5%	555
	11th to 20th	Night	9% 1 18% 41% 26% 4	552
	21st to end	Night	6% 2 16% 45% 29% 2	624
August	1st to 10th	Night	9% 2 9% 46% 29% 4	567
	11th to 20th	Night	9% 2 13% 40% 31% 4	564
	21st to end	Night	11% 1 16% 32% 35% 4	627
September	1st to 10th	Night	12% 2 16% 36% 28% 5%	602
	11th to 20th	Night	10% 4 14% 36% 31% 4	760
	21st to end	Night	17% 6% 24% 29% 21% 4	760
October	1st to 10th	Night	17% 6% 24% 33% 19% 1	760
	11th to 20th	Night	22% 10% 29% 29% 9% 1	760
	21st to end	Night	25% 11% 31% 25% 8%	836
November	1st to 10th	Night	20% 12% 29% 28% 10% 1	780
	11th to 20th	Night	24% 13% 34% 23% 6% 1	800
	21st to end	Night	27% 10% 33% 25% 5%	800
December	1st to 10th	Night	25% 16% 33% 20% 5%	815
	11th to 20th	Night	24% 12% 38% 22% 4	950
	21st to end	Night	31% 13% 34% 19% 3	1045

Page generated at 2024-11-29 10:43:04. Version ac07

Copyright © 2024 Attilla Danko.