Branson Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Branson Observatory clear sky chart from 2005-11-06 to 2024-11-30.

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% 2 6% 4 4 4 4 5% 7% 45%	101075
	Night	13% 7% 2 5% 4 3 4 3 5% 6% 49%	98547
Transparency	Day	36% 7% 11% 25% 18% 4	104724
	Night	34% 6% 11% 25% 20% 5%	103038
Seeing	Day	15% 11% 25% 26% 17% 5%	15580
	Night	15% 10% 27% 31% 15% 1	25407

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	15% 11% 3 5% 4 4 2 3 3 4 47%	2847
	11th to 20th	Day	11% 8% 2 8% 3 4 4 3 4 6% 47%	2850
	21st to end	Day	23% 9% 3 6% 3 2 3 2 4 5% 41%	3135
February	1st to 10th	Day	16% 10% 3 7% 5% 4 4 3 4 4 40%	1710
	11th to 20th	Day	16% 9% 3 6% 5% 2 3 4 4 4 45%	1702
	21st to end	Day	16% 9% 3 6% 4 4 5% 3 5% 7% 38%	1646
March	1st to 10th	Day	17% 9% 2 5% 3 3 3 2 4 5% 47%	3436
	11th to 20th	Day	13% 6% 2 4 3 3 4 3 4 7% 51%	3480
	21st to end	Day	16% 10% 3 8% 5% 4 5% 4 4 6% 35%	3814
April	1st to 10th	Day	13% 6% 2 6% 4 5% 4 4 6% 6% 45%	2250
	11th to 20th	Day	16% 8% 3 6% 4 5% 5% 3 6% 5% 40%	2254
	21st to end	Day	20% 8% 3 7% 5% 4 4 2 4 5% 39%	2280
May	1st to 10th	Day	16% 8% 2 7% 5% 5% 5% 4 6% 6% 36%	3975
	11th to 20th	Day	13% 7% 2 7% 5% 4 5% 4 6% 7% 40%	4082
	21st to end	Day	14% 6% 2 7% 5% 5% 5% 4 6% 8% 38%	4540
June	1st to 10th	Day	7% 5% 1 6% 4 5% 5% 4 7% 10% 44%	2660
	11th to 20th	Day	6% 3 1 5% 5% 5% 5% 6% 7% 10% 47%	2660
	21st to end	Day	5% 3 1 4 4 5% 5% 5% 7% 10% 51%	2606
July	1st to 10th	Day	11% 5% 2 5% 5% 4 4 4 6% 10% 43%	4120
	11th to 20th	Day	5% 4 2 5% 4 4 5% 4 7% 11% 49%	4120
	21st to end	Day	7% 5% 2 6% 5% 5% 6% 5% 9% 11% 39%	4465
August	1st to 10th	Day	5% 3 1 5% 3 4 5% 3 6% 8% 57%	4104
	11th to 20th	Day	10% 5% 2 6% 5% 4 5% 3 6% 8% 46%	3900
	21st to end	Day	5% 4 2 4 4 4 4 4 6% 9% 55%	4180
September	1st to 10th	Day	10% 5% 2 5% 4 5% 4 4 5% 7% 49%	2280
	11th to 20th	Day	10% 6% 2 6% 4 4 5% 4 5% 7% 47%	2219
	21st to end	Day	7% 4 1 5% 4 4 4 4 6% 7% 53%	2011
October	1st to 10th	Day	9% 4 2 4 3 3 4 3 4 5% 58%	1900
	11th to 20th	Day	13% 5% 2 4 3 3 3 2 3 5% 57%	1900
	21st to end	Day	17% 7% 2 5% 3 3 3 2 4 5% 50%	2090
November	1st to 10th	Day	13% 6% 2 4 3 2 3 2 4 4 56%	1958
	11th to 20th	Day	13% 7% 2 5% 3 3 3 3 5% 6% 51%	1906
	21st to end	Day	16% 8% 2 5% 3 4 2 3 3 5% 48%	1602
December	1st to 10th	Day	13% 8% 3 6% 4 3 3 3 4 6% 46%	1520
	11th to 20th	Day	15% 9% 3 7% 5% 5% 4 3 4 3 43%	1918
	21st to end	Day	13% 18% 4 8% 4 4 5% 3 5% 5% 30%	2955
January	1st to 10th	Night	14% 9% 4 8% 4 5% 4 4 4 5% 40%	4108
	11th to 20th	Night	12% 6% 2 8% 4 3 4 3 4 5% 47%	4120
	21st to end	Night	22% 11% 3 5% 3 2 2 2 3 5% 42%	4532
February	1st to 10th	Night	16% 9% 3 7% 3 3 3 3 5% 6% 42%	2470
	11th to 20th	Night	16% 7% 3 7% 4 3 3 3 4 4 47%	2364
	21st to end	Night	17% 8% 2 5% 3 3 4 2 5% 6% 46%	1822
March	1st to 10th	Night	19% 8% 2 5% 3 3 3 2 4 5% 45%	3419
	11th to 20th	Night	12% 7% 2 5% 4 3 3 2 5% 6% 52%	3480
	21st to end	Night	16% 8% 3 7% 4 4 4 3 5% 6% 40%	3817
April	1st to 10th	Night	11% 6% 2 4 3 3 5% 3 5% 7% 52%	1929
	11th to 20th	Night	14% 6% 2 5% 3 3 4 4 5% 7% 47%	1875
	21st to end	Night	19% 6% 2 6% 3 4 4 4 5% 7% 41%	1900
May	1st to 10th	Night	15% 7% 2 5% 4 4 4 3 6% 6% 46%	2924
	11th to 20th	Night	13% 7% 2 5% 4 4 5% 5% 6% 8% 41%	2823
	21st to end	Night	12% 7% 2 6% 4 5% 4 4 6% 9% 41%	3005
June	1st to 10th	Night	7% 3 2 4 3 4 3 3 7% 10% 54%	1520
	11th to 20th	Night	4 2 1 4 3 3 4 4 8% 11% 56%	1520
	21st to end	Night	3 2 1 3 4 3 4 4 6% 7% 62%	1565
July	1st to 10th	Night	9% 5% 1 6% 5% 4 4 4 5% 8% 49%	2850
	11th to 20th	Night	5% 3 1 4 3 4 4 4 5% 9% 60%	2850
	21st to end	Night	6% 5% 2 7% 5% 3 5% 4 6% 9% 48%	3098
August	1st to 10th	Night	4 2 1 4 3 3 4 3 5% 9% 61%	2836
	11th to 20th	Night	8% 4 2 6% 4 4 4 4 6% 8% 51%	2921
	21st to end	Night	5% 3 1 3 3 3 4 3 6% 7% 62%	3476
September	1st to 10th	Night	9% 4 1 5% 3 3 4 3 6% 7% 56%	1900
	11th to 20th	Night	10% 4 2 6% 4 4 3 3 4 6% 53%	1957
	21st to end	Night	8% 5% 1 5% 3 3 4 2 4 7% 58%	2148
October	1st to 10th	Night	7% 3 1 5% 3 3 3 3 4 6% 61%	2280
	11th to 20th	Night	13% 5% 1 3 3 3 3 2 5% 5% 57%	2280
	21st to end	Night	17% 7% 2 4 3 3 3 2 3 5% 52%	2508
November	1st to 10th	Night	13% 5% 1 4 3 3 2 2 4 5% 58%	2340
	11th to 20th	Night	11% 5% 2 5% 2 3 3 3 5% 5% 55%	2490
	21st to end	Night	16% 7% 2 4 4 3 3 2 4 5% 50%	2789
December	1st to 10th	Night	16% 8% 3 6% 3 3 3 3 4 6% 47%	2660
	11th to 20th	Night	16% 9% 3 7% 4 4 3 2 4 5% 43%	3279
	21st to end	Night	18% 15% 4 7% 4 3 4 3 4 4 33%	4692

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	42% 4 7% 26% 19% 2	2848
	11th to 20th	Day	39% 5% 13% 25% 15% 4	2850
	21st to end	Day	47% 4 9% 19% 16% 4	3135
February	1st to 10th	Day	48% 5% 10% 22% 13% 3	1710
	11th to 20th	Day	44% 5% 9% 22% 17% 4	1711
	21st to end	Day	46% 6% 8% 20% 13% 8%	1646
March	1st to 10th	Day	40% 6% 8% 19% 19% 9%	3436
	11th to 20th	Day	34% 6% 10% 26% 19% 5%	3480
	21st to end	Day	48% 7% 10% 22% 11% 1	3814
April	1st to 10th	Day	38% 6% 11% 23% 20% 2	2250
	11th to 20th	Day	43% 7% 11% 19% 17% 3	2254
	21st to end	Day	49% 5% 8% 22% 14% 2	2280
May	1st to 10th	Day	44% 10% 11% 20% 14% 1	4011
	11th to 20th	Day	39% 11% 13% 24% 12% 1	4086
	21st to end	Day	40% 10% 14% 21% 14% 1	4553
June	1st to 10th	Day	33% 10% 15% 26% 14% 1	2660
	11th to 20th	Day	29% 10% 14% 30% 15% 2	2660
	21st to end	Day	25% 9% 17% 28% 16% 4	2606
July	1st to 10th	Day	34% 8% 16% 27% 13% 1	4056
	11th to 20th	Day	27% 7% 14% 34% 18% 1	4051
	21st to end	Day	33% 9% 21% 28% 9%	4325
August	1st to 10th	Day	23% 7% 17% 29% 21% 3	4090
	11th to 20th	Day	35% 7% 16% 28% 13% 1	3939
	21st to end	Day	25% 7% 13% 36% 16% 3	4179
September	1st to 10th	Day	34% 7% 11% 23% 17% 9%	2280
	11th to 20th	Day	35% 7% 9% 23% 23% 3	2219
	21st to end	Day	28% 8% 9% 26% 25% 3	2011
October	1st to 10th	Day	17% 4 6% 17% 42% 15%	3160
	11th to 20th	Day	20% 3 5% 21% 39% 13%	3140
	21st to end	Day	29% 4 8% 31% 25% 4	3428
November	1st to 10th	Day	32% 4 8% 27% 22% 7%	1958
	11th to 20th	Day	34% 4 8% 23% 23% 8%	1906
	21st to end	Day	40% 4 9% 21% 23% 3	1602
December	1st to 10th	Day	40% 5% 9% 27% 16% 2	1520
	11th to 20th	Day	45% 5% 7% 17% 24% 3	1915
	21st to end	Day	54% 7% 8% 17% 12% 2	2955
January	1st to 10th	Night	44% 5% 10% 22% 17% 2	4108
	11th to 20th	Night	40% 8% 11% 22% 18% 2	4120
	21st to end	Night	48% 3 10% 19% 18% 2	4532
February	1st to 10th	Night	44% 5% 10% 23% 15% 3	2470
	11th to 20th	Night	42% 4 9% 23% 19% 4	2365
	21st to end	Night	40% 5% 9% 20% 19% 7%	1822
March	1st to 10th	Night	41% 6% 8% 18% 18% 8%	3419
	11th to 20th	Night	34% 6% 10% 27% 20% 3	3480
	21st to end	Night	43% 8% 10% 26% 12% 1	3817
April	1st to 10th	Night	32% 5% 11% 24% 21% 5%	1929
	11th to 20th	Night	35% 6% 10% 23% 20% 5%	1875
	21st to end	Night	42% 7% 10% 23% 16% 2	1900
May	1st to 10th	Night	38% 8% 11% 25% 15% 4	2953
	11th to 20th	Night	37% 11% 14% 24% 13% 2	2824
	21st to end	Night	37% 11% 15% 26% 11% 1	3013
June	1st to 10th	Night	24% 8% 15% 32% 18% 3	1520
	11th to 20th	Night	19% 9% 14% 35% 20% 3	1520
	21st to end	Night	20% 7% 15% 31% 20% 7%	1565
July	1st to 10th	Night	32% 7% 17% 24% 17% 4	2805
	11th to 20th	Night	20% 7% 10% 38% 23% 2	2796
	21st to end	Night	31% 7% 18% 31% 12%	2999
August	1st to 10th	Night	20% 6% 17% 34% 23% 1	2826
	11th to 20th	Night	31% 7% 15% 29% 16% 2	2948
	21st to end	Night	20% 6% 13% 37% 20% 3	3476
September	1st to 10th	Night	25% 7% 12% 30% 18% 8%	1900
	11th to 20th	Night	33% 6% 10% 23% 24% 5%	1957
	21st to end	Night	28% 4 10% 23% 31% 4	2148
October	1st to 10th	Night	14% 3 7% 15% 41% 20%	3800
	11th to 20th	Night	20% 3 5% 18% 34% 20%	3779
	21st to end	Night	28% 4 6% 32% 25% 6%	4120
November	1st to 10th	Night	30% 4 9% 25% 25% 7%	2340
	11th to 20th	Night	31% 4 8% 24% 26% 7%	2490
	21st to end	Night	37% 4 7% 24% 23% 4	2789
December	1st to 10th	Night	39% 5% 11% 23% 19% 2	2660
	11th to 20th	Night	44% 4 7% 22% 20% 3	3281
	21st to end	Night	53% 7% 10% 18% 10% 3	4692

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	24% 21% 32% 20% 3	270
	11th to 20th	Day	29% 24% 34% 11% 1	270
	21st to end	Day	20% 32% 32% 12% 5%	297
February	1st to 10th	Day	24% 27% 34% 12% 3	270
	11th to 20th	Day	27% 29% 28% 14% 3	270
	21st to end	Day	35% 22% 35% 8% 1	225
March	1st to 10th	Day	23% 25% 33% 17% 1	270
	11th to 20th	Day	32% 20% 31% 16% 1	270
	21st to end	Day	27% 25% 38% 7% 3	297
April	1st to 10th	Day	23% 22% 30% 17% 7%	430
	11th to 20th	Day	25% 19% 32% 18% 6%	452
	21st to end	Day	27% 16% 32% 20% 5% 1	460
May	1st to 10th	Day	21% 15% 32% 23% 8% 1	583
	11th to 20th	Day	16% 11% 32% 25% 13% 3	675
	21st to end	Day	11% 9% 38% 23% 15% 4	734
June	1st to 10th	Day	9% 4 22% 34% 25% 6%	680
	11th to 20th	Day	4 3 20% 39% 27% 6%	680
	21st to end	Day	5% 4 26% 35% 26% 4	680
July	1st to 10th	Day	10% 2 14% 34% 31% 9%	671
	11th to 20th	Day	5% 3 14% 35% 33% 10%	668
	21st to end	Day	8% 1 10% 32% 36% 13%	739
August	1st to 10th	Day	8% 4 12% 41% 28% 7%	676
	11th to 20th	Day	12% 3 13% 35% 30% 7%	589
	21st to end	Day	8% 2 10% 29% 34% 16%	539
September	1st to 10th	Day	10% 2 13% 32% 32% 10%	490
	11th to 20th	Day	10% 2 17% 37% 26% 9%	429
	21st to end	Day	9% 5% 29% 26% 26% 5%	300
October	1st to 10th	Day	10% 8% 28% 28% 22% 3	300
	11th to 20th	Day	16% 14% 34% 26% 10%	300
	21st to end	Day	25% 15% 31% 22% 5% 1	330
November	1st to 10th	Day	17% 14% 31% 28% 8% 2	300
	11th to 20th	Day	18% 19% 35% 20% 8% 1	300
	21st to end	Day	27% 18% 27% 20% 7% 1	299
December	1st to 10th	Day	18% 27% 29% 18% 6% 3	270
	11th to 20th	Day	26% 20% 26% 24% 4	270
	21st to end	Day	24% 25% 34% 15% 2	297
January	1st to 10th	Night	20% 17% 34% 24% 5%	950
	11th to 20th	Night	22% 19% 35% 22% 3	950
	21st to end	Night	18% 18% 37% 23% 3	1045
February	1st to 10th	Night	22% 15% 37% 22% 4	950
	11th to 20th	Night	22% 16% 41% 20% 2	890
	21st to end	Night	24% 18% 39% 18% 2	566
March	1st to 10th	Night	21% 15% 35% 26% 4	570
	11th to 20th	Night	23% 14% 29% 28% 6%	570
	21st to end	Night	22% 12% 37% 23% 5%	627
April	1st to 10th	Night	15% 15% 36% 28% 5%	570
	11th to 20th	Night	16% 14% 33% 29% 7%	563
	21st to end	Night	21% 11% 36% 25% 8%	570
May	1st to 10th	Night	15% 8% 30% 39% 9%	570
	11th to 20th	Night	15% 7% 27% 32% 18% 1	561
	21st to end	Night	11% 5% 24% 37% 20% 3	617
June	1st to 10th	Night	8% 4 15% 40% 33% 1	570
	11th to 20th	Night	4 2 18% 45% 29% 2	570
	21st to end	Night	2 2 18% 45% 32% 1	570
July	1st to 10th	Night	7% 1 8% 42% 36% 6%	555
	11th to 20th	Night	3 1 9% 41% 40% 6%	552
	21st to end	Night	6% 2 8% 41% 37% 6%	624
August	1st to 10th	Night	5% 1 9% 42% 39% 4	567
	11th to 20th	Night	8% 2 11% 42% 34% 4	564
	21st to end	Night	7% 9% 37% 41% 6%	627
September	1st to 10th	Night	10% 1 11% 39% 36% 2	570
	11th to 20th	Night	12% 1 9% 42% 31% 5%	570
	21st to end	Night	10% 3 22% 33% 29% 3	628
October	1st to 10th	Night	7% 3 22% 37% 27% 3	760
	11th to 20th	Night	16% 9% 29% 33% 13% 1	760
	21st to end	Night	20% 11% 28% 31% 10%	836
November	1st to 10th	Night	15% 9% 31% 34% 11% 1	780
	11th to 20th	Night	14% 12% 34% 31% 9%	800
	21st to end	Night	20% 13% 30% 28% 10%	990
December	1st to 10th	Night	20% 12% 35% 27% 6%	950
	11th to 20th	Night	24% 13% 30% 29% 4	950
	21st to end	Night	22% 17% 33% 24% 4	1045

Page generated at 2024-11-27 16:30:48. Version ac07

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