Zaug's Observing Site - Sangre De Cristo Ranches
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Zaug's Observing Site - Sangre De Cristo Ranches clear sky chart from 2005-11-06 to 2026-04-17.

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	2 5% 2 6% 4 4 5% 4 6% 8% 54%	140146
	Night	2 5% 2 5% 4 4 4 4 6% 7% 58%	139534
Transparency	Day	27% 7% 11% 24% 24% 9%	135142
	Night	25% 6% 11% 26% 25% 7%	135545
Seeing	Day	10% 24% 30% 23% 11% 2	17262
	Night	6% 19% 33% 29% 12% 1	27440

By Month

Percentage Cloud Cover SW (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	4 4 11% 5% 4 3 3 4 6% 57%	4720
	11th to 20th	Day	3 2 7% 4 3 3 2 4 5% 67%	5298
	21st to end	Day	1 7% 3 8% 3 3 4 3 5% 6% 57%	5844
February	1st to 10th	Day	6% 4 7% 4 3 3 2 6% 6% 59%	1917
	11th to 20th	Day	1 4 3 6% 4 3 4 3 6% 7% 59%	2049
	21st to end	Day	7% 4 8% 4 3 3 3 4 6% 58%	1730
March	1st to 10th	Day	8% 3 5% 4 3 4 3 5% 5% 60%	4636
	11th to 20th	Day	1 8% 4 11% 6% 5% 5% 4 6% 8% 42%	5110
	21st to end	Day	1 7% 3 7% 4 4 4 4 5% 8% 53%	5910
April	1st to 10th	Day	2 7% 2 6% 4 4 4 4 5% 7% 53%	2520
	11th to 20th	Day	2 10% 3 7% 4 4 4 4 5% 7% 51%	2444
	21st to end	Day	4 10% 2 6% 4 4 4 5% 6% 6% 48%	2400
May	1st to 10th	Day	4 8% 3 6% 4 5% 4 4 6% 6% 49%	5478
	11th to 20th	Day	3 5% 2 5% 4 4 5% 4 6% 7% 54%	6074
	21st to end	Day	2 3 1 4 4 4 5% 4 7% 8% 57%	6925
June	1st to 10th	Day	3 4 1 4 3 4 5% 5% 8% 9% 52%	2800
	11th to 20th	Day	3 2 1 3 3 4 3 4 6% 7% 63%	2800
	21st to end	Day	3 3 2 6% 4 5% 6% 6% 8% 9% 49%	2800
July	1st to 10th	Day	2 3 1 4 4 5% 5% 5% 7% 7% 57%	6339
	11th to 20th	Day	2 2 1 4 5% 6% 9% 7% 10% 11% 41%	6340
	21st to end	Day	4 4 2 6% 6% 7% 7% 6% 9% 9% 41%	6405
August	1st to 10th	Day	4 4 2 6% 5% 6% 8% 6% 10% 10% 39%	5651
	11th to 20th	Day	3 3 1 4 4 4 5% 5% 9% 10% 52%	5366
	21st to end	Day	4 4 2 6% 6% 6% 7% 6% 9% 11% 37%	5984
September	1st to 10th	Day	5% 4 2 6% 5% 5% 5% 5% 6% 8% 50%	2400
	11th to 20th	Day	5% 4 1 5% 4 4 5% 4 6% 6% 58%	2385
	21st to end	Day	4 4 2 5% 4 3 4 3 5% 6% 62%	2200
October	1st to 10th	Day	3 4 1 3 2 2 2 2 3 5% 72%	3283
	11th to 20th	Day	3 4 1 4 3 4 5% 4 5% 7% 60%	3250
	21st to end	Day	3 4 1 3 3 2 2 2 4 5% 70%	3548
November	1st to 10th	Day	1 3 2 4 3 3 3 3 5% 8% 66%	1862
	11th to 20th	Day	1 4 1 4 3 3 3 3 5% 7% 66%	1890
	21st to end	Day	2 6% 2 5% 3 3 3 3 5% 6% 61%	1890
December	1st to 10th	Day	1 4 2 5% 2 2 2 1 4 7% 71%	2700
	11th to 20th	Day	3 1 4 3 3 2 4 5% 10% 63%	3106
	21st to end	Day	5% 2 6% 3 3 4 3 5% 8% 60%	4092
January	1st to 10th	Night	3 3 9% 4 3 3 3 5% 6% 60%	8201
	11th to 20th	Night	3 1 6% 3 3 3 2 4 6% 69%	7734
	21st to end	Night	1 6% 3 6% 4 3 3 2 4 5% 62%	8370
February	1st to 10th	Night	1 7% 3 7% 3 2 3 3 4 7% 62%	2700
	11th to 20th	Night	1 7% 3 7% 3 3 3 3 4 7% 58%	2458
	21st to end	Night	1 8% 3 6% 3 3 3 3 4 7% 59%	2076
March	1st to 10th	Night	1 7% 4 7% 3 3 3 3 4 5% 60%	5454
	11th to 20th	Night	1 8% 3 6% 4 4 3 3 4 6% 56%	5110
	21st to end	Night	2 8% 3 7% 4 3 3 3 4 7% 56%	5293
April	1st to 10th	Night	2 6% 2 5% 4 2 4 3 5% 8% 60%	2100
	11th to 20th	Night	2 8% 2 5% 4 4 3 3 5% 7% 56%	2037
	21st to end	Night	5% 8% 2 5% 3 4 4 3 5% 7% 55%	2000
May	1st to 10th	Night	5% 6% 2 5% 4 4 4 4 5% 6% 55%	4499
	11th to 20th	Night	3 4 1 5% 4 4 5% 4 6% 7% 58%	3837
	21st to end	Night	3 4 1 4 3 4 5% 4 5% 7% 59%	3972
June	1st to 10th	Night	2 3 1 4 4 4 5% 5% 7% 9% 56%	1600
	11th to 20th	Night	1 2 3 3 3 4 5% 6% 9% 65%	1600
	21st to end	Night	4 4 1 5% 4 5% 5% 5% 8% 10% 50%	1600
July	1st to 10th	Night	2 3 1 5% 4 5% 6% 6% 7% 7% 54%	3640
	11th to 20th	Night	2 2 1 5% 5% 6% 8% 7% 10% 11% 42%	3640
	21st to end	Night	3 4 2 6% 5% 5% 7% 7% 10% 11% 40%	4463
August	1st to 10th	Night	5% 3 2 7% 5% 6% 6% 5% 7% 9% 42%	4158
	11th to 20th	Night	3 3 1 5% 4 5% 6% 6% 11% 14% 43%	4483
	21st to end	Night	6% 5% 2 7% 6% 6% 8% 7% 11% 10% 32%	4993
September	1st to 10th	Night	4 4 2 5% 5% 5% 5% 5% 7% 8% 51%	2000
	11th to 20th	Night	4 3 1 3 4 3 5% 4 5% 7% 61%	2014
	21st to end	Night	4 3 1 4 2 3 4 3 5% 6% 66%	2200
October	1st to 10th	Night	3 3 1 3 2 3 3 3 4 5% 70%	3903
	11th to 20th	Night	2 4 2 4 3 3 4 3 5% 7% 64%	3898
	21st to end	Night	2 3 2 3 2 2 2 2 4 5% 72%	4252
November	1st to 10th	Night	1 2 1 3 3 2 3 2 4 7% 72%	2635
	11th to 20th	Night	1 3 1 2 2 2 3 2 5% 7% 71%	2730
	21st to end	Night	2 6% 2 4 4 3 3 4 5% 7% 60%	2730
December	1st to 10th	Night	1 4 2 4 2 2 2 2 3 6% 71%	4705
	11th to 20th	Night	1 3 1 4 3 2 3 3 5% 8% 68%	5321
	21st to end	Night	1 6% 3 8% 4 3 3 3 5% 6% 56%	7128

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	30% 5% 9% 32% 19% 7%	4723
	11th to 20th	Day	20% 3 11% 28% 26% 11%	5298
	21st to end	Day	28% 3 8% 22% 26% 13%	5844
February	1st to 10th	Day	27% 4 12% 28% 22% 8%	1917
	11th to 20th	Day	27% 5% 9% 28% 24% 7%	2059
	21st to end	Day	29% 4 5% 21% 29% 13%	1730
March	1st to 10th	Day	24% 5% 7% 19% 31% 14%	4636
	11th to 20th	Day	37% 6% 8% 26% 20% 4	5110
	21st to end	Day	28% 6% 9% 39% 16% 2	5910
April	1st to 10th	Day	31% 5% 8% 25% 23% 9%	2520
	11th to 20th	Day	33% 6% 5% 26% 22% 8%	2447
	21st to end	Day	35% 5% 7% 24% 24% 4	2400
May	1st to 10th	Day	31% 8% 9% 21% 22% 10%	5478
	11th to 20th	Day	27% 5% 9% 23% 28% 8%	6078
	21st to end	Day	21% 8% 8% 21% 32% 10%	6926
June	1st to 10th	Day	25% 7% 13% 25% 21% 10%	2800
	11th to 20th	Day	21% 5% 8% 19% 26% 22%	2800
	21st to end	Day	29% 6% 9% 23% 21% 12%	2800
July	1st to 10th	Day	23% 8% 10% 15% 22% 23%	6271
	11th to 20th	Day	26% 16% 23% 25% 7% 3	6265
	21st to end	Day	34% 13% 19% 19% 13% 3	6220
August	1st to 10th	Day	40% 15% 19% 14% 8% 4	4113
	11th to 20th	Day	27% 8% 18% 20% 19% 8%	3882
	21st to end	Day	37% 11% 19% 17% 14% 2	4311
September	1st to 10th	Day	32% 6% 11% 23% 20% 7%	2400
	11th to 20th	Day	27% 4 9% 20% 29% 10%	2385
	21st to end	Day	25% 4 6% 26% 33% 7%	2200
October	1st to 10th	Day	18% 3 4 22% 38% 14%	3283
	11th to 20th	Day	22% 9% 7% 28% 28% 7%	3250
	21st to end	Day	17% 4 6% 22% 44% 7%	3548
November	1st to 10th	Day	18% 3 8% 26% 34% 10%	1862
	11th to 20th	Day	19% 5% 9% 31% 30% 7%	1890
	21st to end	Day	25% 4 8% 23% 29% 11%	1890
December	1st to 10th	Day	16% 3 10% 27% 37% 8%	2700
	11th to 20th	Day	19% 4 8% 29% 34% 5%	3104
	21st to end	Day	22% 5% 9% 29% 25% 9%	4092
January	1st to 10th	Night	25% 4 9% 36% 21% 5%	8202
	11th to 20th	Night	19% 3 10% 31% 24% 12%	7734
	21st to end	Night	24% 4 9% 23% 29% 12%	8370
February	1st to 10th	Night	26% 3 13% 25% 26% 7%	2700
	11th to 20th	Night	28% 4 11% 29% 22% 6%	2458
	21st to end	Night	28% 3 5% 24% 31% 9%	2076
March	1st to 10th	Night	26% 6% 6% 17% 36% 10%	5454
	11th to 20th	Night	28% 4 9% 26% 26% 6%	5110
	21st to end	Night	28% 7% 12% 36% 15% 2	5293
April	1st to 10th	Night	24% 5% 11% 30% 23% 7%	2100
	11th to 20th	Night	28% 4 8% 27% 28% 5%	2037
	21st to end	Night	32% 3 11% 30% 21% 3	2000
May	1st to 10th	Night	28% 7% 8% 26% 24% 7%	4496
	11th to 20th	Night	23% 6% 11% 29% 23% 8%	3838
	21st to end	Night	22% 7% 11% 20% 32% 8%	3972
June	1st to 10th	Night	22% 6% 15% 24% 20% 12%	1600
	11th to 20th	Night	16% 4 10% 24% 24% 22%	1600
	21st to end	Night	28% 6% 11% 23% 22% 10%	1600
July	1st to 10th	Night	25% 8% 14% 17% 20% 17%	3600
	11th to 20th	Night	29% 12% 25% 25% 7% 3	3592
	21st to end	Night	33% 13% 20% 20% 14% 1	4336
August	1st to 10th	Night	42% 12% 20% 14% 8% 4	3020
	11th to 20th	Night	29% 12% 21% 19% 14% 5%	3243
	21st to end	Night	36% 12% 17% 20% 12% 2	3597
September	1st to 10th	Night	29% 6% 14% 26% 20% 5%	2000
	11th to 20th	Night	23% 6% 11% 21% 29% 11%	2014
	21st to end	Night	21% 5% 9% 28% 32% 6%	2200
October	1st to 10th	Night	17% 3 8% 27% 35% 10%	3903
	11th to 20th	Night	20% 6% 8% 28% 31% 7%	3898
	21st to end	Night	16% 3 6% 29% 39% 7%	4252
November	1st to 10th	Night	15% 4 9% 30% 35% 8%	2635
	11th to 20th	Night	15% 3 7% 35% 32% 8%	2730
	21st to end	Night	25% 4 8% 24% 29% 10%	2730
December	1st to 10th	Night	18% 3 9% 32% 32% 7%	4705
	11th to 20th	Night	18% 3 9% 29% 34% 7%	5322
	21st to end	Night	28% 6% 12% 21% 28% 5%	7128

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	11% 32% 30% 21% 6% 1	330
	11th to 20th	Day	10% 31% 38% 18% 2 1	330
	21st to end	Day	6% 26% 42% 18% 7% 1	363
February	1st to 10th	Day	13% 40% 28% 15% 3 1	330
	11th to 20th	Day	17% 42% 26% 13% 2	330
	21st to end	Day	21% 37% 29% 12% 2	273
March	1st to 10th	Day	19% 36% 26% 15% 4	340
	11th to 20th	Day	18% 35% 30% 13% 4 1	540
	21st to end	Day	21% 38% 31% 8% 2	594
April	1st to 10th	Day	18% 38% 32% 11% 2	540
	11th to 20th	Day	24% 41% 27% 7% 2	517
	21st to end	Day	18% 40% 28% 11% 2	500
May	1st to 10th	Day	16% 37% 33% 10% 4	515
	11th to 20th	Day	9% 25% 34% 23% 7% 2	725
	21st to end	Day	8% 27% 31% 24% 10% 1	789
June	1st to 10th	Day	3 17% 34% 28% 16% 2	730
	11th to 20th	Day	6% 19% 35% 25% 13% 2	730
	21st to end	Day	5% 16% 31% 28% 17% 3	730
July	1st to 10th	Day	5% 8% 26% 36% 22% 3	721
	11th to 20th	Day	5% 3 18% 41% 28% 5%	718
	21st to end	Day	6% 4 23% 39% 25% 3	579
August	1st to 10th	Day	6% 8% 30% 34% 20% 2	527
	11th to 20th	Day	4 7% 29% 39% 17% 3	517
	21st to end	Day	7% 8% 30% 36% 16% 3	583
September	1st to 10th	Day	6% 10% 30% 35% 16% 3	530
	11th to 20th	Day	6% 19% 35% 28% 11% 2	515
	21st to end	Day	5% 17% 33% 27% 12% 5%	330
October	1st to 10th	Day	10% 25% 24% 23% 14% 4	330
	11th to 20th	Day	13% 29% 29% 18% 8% 3	330
	21st to end	Day	13% 26% 28% 23% 8% 2	363
November	1st to 10th	Day	12% 31% 33% 16% 8%	330
	11th to 20th	Day	10% 26% 32% 21% 10%	330
	21st to end	Day	10% 30% 29% 24% 6%	330
December	1st to 10th	Day	13% 27% 36% 18% 6% 1	330
	11th to 20th	Day	8% 33% 37% 18% 4 1	330
	21st to end	Day	18% 31% 34% 15% 2	363
January	1st to 10th	Night	5% 22% 37% 27% 8% 1	1050
	11th to 20th	Night	6% 21% 36% 27% 9% 1	872
	21st to end	Night	3 18% 40% 30% 8% 1	924
February	1st to 10th	Night	6% 25% 44% 21% 4	840
	11th to 20th	Night	7% 32% 41% 16% 5%	824
	21st to end	Night	9% 26% 46% 18% 1	692
March	1st to 10th	Night	8% 30% 38% 20% 4	840
	11th to 20th	Night	6% 24% 40% 24% 6%	840
	21st to end	Night	8% 28% 39% 21% 4	788
April	1st to 10th	Night	10% 32% 40% 16% 2	630
	11th to 20th	Night	12% 26% 36% 22% 5%	611
	21st to end	Night	9% 25% 41% 21% 5%	600
May	1st to 10th	Night	10% 20% 36% 26% 8% 1	600
	11th to 20th	Night	8% 18% 36% 27% 10% 1	591
	21st to end	Night	8% 21% 32% 26% 12% 1	650
June	1st to 10th	Night	3 11% 32% 36% 17% 1	600
	11th to 20th	Night	2 15% 34% 37% 12% 1	600
	21st to end	Night	3 8% 29% 36% 22% 2	600
July	1st to 10th	Night	6% 3 22% 39% 27% 2	585
	11th to 20th	Night	4 2 12% 42% 36% 4	582
	21st to end	Night	6% 1 13% 37% 37% 6%	657
August	1st to 10th	Night	5% 4 14% 39% 34% 5%	597
	11th to 20th	Night	5% 4 16% 49% 23% 4	594
	21st to end	Night	6% 4 19% 41% 25% 4	660
September	1st to 10th	Night	4 7% 20% 43% 22% 5%	600
	11th to 20th	Night	5% 9% 29% 35% 20% 3	600
	21st to end	Night	5% 14% 25% 40% 15% 2	600
October	1st to 10th	Night	6% 16% 31% 34% 11% 1	783
	11th to 20th	Night	5% 18% 34% 28% 12% 3	800
	21st to end	Night	7% 18% 33% 28% 13% 2	880
November	1st to 10th	Night	6% 20% 32% 29% 11% 1	995
	11th to 20th	Night	5% 21% 38% 25% 10% 1	1050
	21st to end	Night	7% 23% 31% 30% 10% 1	1050
December	1st to 10th	Night	7% 23% 36% 26% 8%	1050
	11th to 20th	Night	6% 27% 36% 24% 7%	1050
	21st to end	Night	8% 25% 37% 26% 4 1	1155

Page generated at 2026-04-14 00:44:30. Version ac07

Copyright © 2026 Attilla Danko.