Laguna Atascosa Wildlife Refuge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Laguna Atascosa Wildlife Refuge clear sky chart from 2005-11-06 to 2026-04-02.

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
Transparency	Day	35% 8% 18% 22% 13% 4	135427
	Night	37% 7% 17% 21% 13% 6%	134765
Seeing	Day	10% 4 16% 31% 30% 9%	16040
	Night	13% 4 14% 32% 30% 7%	26157

By Month

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	40% 6% 12% 23% 13% 5%	5290
	11th to 20th	Day	51% 7% 9% 15% 13% 5%	5370
	21st to end	Day	52% 8% 12% 14% 11% 3	6468
February	1st to 10th	Day	44% 10% 9% 16% 14% 7%	2100
	11th to 20th	Day	37% 10% 13% 19% 16% 4	2059
	21st to end	Day	35% 10% 12% 21% 16% 6%	1825
March	1st to 10th	Day	40% 7% 15% 15% 11% 12%	5046
	11th to 20th	Day	37% 6% 10% 12% 25% 10%	5090
	21st to end	Day	31% 6% 11% 27% 16% 9%	5585
April	1st to 10th	Day	36% 9% 16% 20% 12% 7%	2211
	11th to 20th	Day	39% 9% 14% 19% 13% 6%	2176
	21st to end	Day	35% 9% 16% 20% 15% 5%	2320
May	1st to 10th	Day	36% 10% 21% 20% 10% 2	5706
	11th to 20th	Day	25% 9% 17% 26% 18% 5%	5866
	21st to end	Day	27% 8% 19% 34% 12% 1	6447
June	1st to 10th	Day	21% 9% 19% 32% 18% 1	2600
	11th to 20th	Day	26% 10% 15% 27% 19% 2	2600
	21st to end	Day	33% 11% 22% 26% 7% 1	2600
July	1st to 10th	Day	40% 6% 31% 22% 2	5836
	11th to 20th	Day	32% 6% 37% 21% 4	5831
	21st to end	Day	31% 7% 30% 28% 4	6240
August	1st to 10th	Day	11% 7% 30% 47% 5%	4037
	11th to 20th	Day	23% 8% 44% 23% 2	3823
	21st to end	Day	27% 10% 30% 26% 7% 1	3948
September	1st to 10th	Day	39% 12% 18% 19% 11%	2200
	11th to 20th	Day	41% 12% 16% 19% 10% 1	2200
	21st to end	Day	36% 10% 17% 22% 11% 4	2200
October	1st to 10th	Day	25% 6% 9% 18% 27% 15%	3590
	11th to 20th	Day	26% 6% 14% 19% 29% 6%	3339
	21st to end	Day	29% 6% 8% 23% 27% 7%	3538
November	1st to 10th	Day	33% 10% 10% 22% 19% 5%	2058
	11th to 20th	Day	40% 10% 8% 18% 17% 7%	2100
	21st to end	Day	42% 10% 12% 19% 14% 4	2032
December	1st to 10th	Day	60% 8% 10% 13% 8% 2	3030
	11th to 20th	Day	38% 10% 12% 18% 13% 8%	3479
	21st to end	Day	38% 8% 10% 22% 16% 7%	4587
January	1st to 10th	Night	41% 6% 13% 22% 13% 6%	7635
	11th to 20th	Night	52% 7% 10% 11% 14% 6%	7663
	21st to end	Night	57% 6% 12% 13% 9% 4	7746
February	1st to 10th	Night	42% 10% 11% 15% 14% 8%	2520
	11th to 20th	Night	40% 11% 12% 17% 16% 4	2458
	21st to end	Night	37% 10% 8% 20% 19% 7%	1978
March	1st to 10th	Night	42% 7% 14% 18% 10% 9%	5029
	11th to 20th	Night	41% 5% 10% 12% 16% 16%	5090
	21st to end	Night	34% 5% 11% 22% 21% 7%	5588
April	1st to 10th	Night	41% 7% 16% 21% 10% 5%	2211
	11th to 20th	Night	44% 7% 13% 16% 13% 7%	2173
	21st to end	Night	42% 8% 15% 16% 12% 6%	2076
May	1st to 10th	Night	47% 9% 20% 12% 9% 3	4259
	11th to 20th	Night	35% 9% 16% 20% 16% 5%	4054
	21st to end	Night	41% 8% 19% 26% 6%	4452
June	1st to 10th	Night	21% 9% 21% 31% 17% 2	1800
	11th to 20th	Night	25% 10% 16% 32% 15% 3	1800
	21st to end	Night	27% 12% 28% 26% 7% 1	1800
July	1st to 10th	Night	41% 7% 29% 20% 2	4035
	11th to 20th	Night	32% 8% 40% 19% 2	4026
	21st to end	Night	26% 7% 34% 29% 4	4320
August	1st to 10th	Night	8% 5% 30% 49% 7%	3078
	11th to 20th	Night	22% 6% 46% 25% 2	3297
	21st to end	Night	17% 8% 38% 28% 7% 1	3949
September	1st to 10th	Night	31% 12% 23% 23% 10% 2	2200
	11th to 20th	Night	35% 11% 19% 24% 9% 1	2200
	21st to end	Night	29% 9% 19% 28% 12% 4	2200
October	1st to 10th	Night	20% 5% 9% 19% 27% 20%	3590
	11th to 20th	Night	22% 5% 14% 21% 26% 14%	3763
	21st to end	Night	26% 3 10% 26% 28% 7%	4252
November	1st to 10th	Night	27% 10% 13% 23% 20% 7%	2460
	11th to 20th	Night	35% 9% 11% 21% 14% 8%	2520
	21st to end	Night	36% 10% 16% 20% 12% 6%	2583
December	1st to 10th	Night	58% 7% 9% 13% 10% 2	4380
	11th to 20th	Night	33% 9% 16% 21% 13% 7%	4947
	21st to end	Night	37% 7% 10% 20% 14% 12%	6633

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% 6% 25% 33% 12% 3	330
	11th to 20th	Day	20% 9% 28% 36% 6% 1	330
	21st to end	Day	20% 9% 31% 28% 12% 1	363
February	1st to 10th	Day	17% 7% 25% 35% 15% 2	330
	11th to 20th	Day	21% 8% 28% 29% 12% 2	330
	21st to end	Day	16% 7% 36% 33% 9%	273
March	1st to 10th	Day	16% 8% 28% 38% 9% 1	330
	11th to 20th	Day	17% 8% 34% 31% 11%	330
	21st to end	Day	9% 10% 37% 35% 9%	363
April	1st to 10th	Day	11% 6% 43% 32% 8%	303
	11th to 20th	Day	10% 11% 35% 33% 10% 1	294
	21st to end	Day	11% 6% 37% 35% 10% 1	420
May	1st to 10th	Day	9% 5% 36% 36% 12% 1	613
	11th to 20th	Day	9% 4 29% 44% 14% 1	725
	21st to end	Day	4 2 19% 52% 20% 3	789
June	1st to 10th	Day	2 1 9% 39% 42% 7%	730
	11th to 20th	Day	5% 1 5% 42% 43% 5%	730
	21st to end	Day	6% 1 6% 37% 36% 15%	730
July	1st to 10th	Day	7% 2 4 32% 45% 11%	721
	11th to 20th	Day	4 1 2 22% 56% 16%	718
	21st to end	Day	4 1 1 22% 55% 17%	794
August	1st to 10th	Day	1 21% 52% 25%	621
	11th to 20th	Day	1 1 1 18% 62% 18%	484
	21st to end	Day	3 1 1 16% 44% 34%	363
September	1st to 10th	Day	9% 2 4 19% 42% 24%	330
	11th to 20th	Day	5% 3 4 16% 44% 29%	330
	21st to end	Day	7% 2 3 20% 43% 25%	330
October	1st to 10th	Day	4 2 3 24% 47% 19%	330
	11th to 20th	Day	9% 1 7% 25% 40% 18%	330
	21st to end	Day	13% 2 16% 34% 27% 8%	363
November	1st to 10th	Day	13% 3 11% 31% 35% 8%	330
	11th to 20th	Day	24% 4 9% 27% 27% 8%	330
	21st to end	Day	23% 7% 22% 24% 17% 7%	330
December	1st to 10th	Day	21% 6% 19% 31% 17% 6%	330
	11th to 20th	Day	18% 8% 19% 31% 20% 3	330
	21st to end	Day	17% 7% 19% 37% 15% 4	363
January	1st to 10th	Night	24% 5% 19% 35% 16% 1	1050
	11th to 20th	Night	23% 7% 20% 38% 13%	1046
	21st to end	Night	22% 7% 21% 36% 14% 1	924
February	1st to 10th	Night	22% 5% 22% 35% 15%	840
	11th to 20th	Night	24% 8% 19% 35% 14%	824
	21st to end	Night	20% 6% 24% 39% 10%	594
March	1st to 10th	Night	18% 6% 26% 37% 13%	630
	11th to 20th	Night	17% 6% 25% 39% 13%	630
	21st to end	Night	13% 7% 24% 42% 14% 2	693
April	1st to 10th	Night	17% 6% 26% 40% 11%	603
	11th to 20th	Night	13% 6% 26% 40% 15%	593
	21st to end	Night	14% 6% 26% 42% 12% 1	600
May	1st to 10th	Night	14% 4 24% 46% 13%	600
	11th to 20th	Night	9% 3 22% 47% 18%	591
	21st to end	Night	8% 2 14% 45% 28% 2	650
June	1st to 10th	Night	2 1 6% 33% 52% 7%	600
	11th to 20th	Night	3 1 5% 42% 44% 6%	600
	21st to end	Night	5% 1 5% 32% 42% 15%	600
July	1st to 10th	Night	7% 4 27% 50% 11%	585
	11th to 20th	Night	2 1 3 19% 59% 16%	582
	21st to end	Night	4 1 2 15% 66% 13%	657
August	1st to 10th	Night	1 1 15% 62% 21%	597
	11th to 20th	Night	3 1 1 12% 60% 23%	594
	21st to end	Night	4 1 3 10% 54% 29%	660
September	1st to 10th	Night	7% 2 13% 55% 24%	600
	11th to 20th	Night	10% 1 12% 52% 24%	600
	21st to end	Night	9% 3 15% 55% 18%	600
October	1st to 10th	Night	4 2 3 22% 54% 16%	600
	11th to 20th	Night	8% 1 6% 29% 47% 9%	716
	21st to end	Night	10% 2 12% 37% 34% 5%	880
November	1st to 10th	Night	11% 3 8% 33% 39% 6%	820
	11th to 20th	Night	19% 3 11% 29% 35% 3	840
	21st to end	Night	17% 4 17% 36% 23% 2	903
December	1st to 10th	Night	21% 7% 15% 34% 20% 4	1050
	11th to 20th	Night	19% 6% 16% 35% 21% 2	1050
	21st to end	Night	18% 5% 22% 35% 18% 2	1155

Page generated at 2026-03-30 01:18:39. Version ac07

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