Pedernales Falls State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pedernales Falls State Park clear sky chart from 2005-11-06 to 2026-06-16.

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	11% 6% 2 5% 4 4 4 4 5% 7% 48%	137765
	Night	11% 6% 2 5% 3 3 4 3 5% 7% 52%	134613
Transparency	Day	34% 5% 10% 21% 20% 10%	141544
	Night	32% 5% 10% 20% 20% 13%	138901
Seeing	Day	12% 8% 24% 31% 20% 5%	16967
	Night	13% 7% 29% 36% 14% 1	26915

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	11% 8% 2 4 3 4 3 2 4 5% 53%	5289
	11th to 20th	Day	13% 5% 2 4 3 2 3 3 5% 6% 56%	5310
	21st to end	Day	21% 9% 3 7% 4 2 2 2 3 5% 41%	6229
February	1st to 10th	Day	16% 6% 2 6% 3 3 4 3 4 5% 48%	2100
	11th to 20th	Day	15% 7% 2 5% 3 3 3 3 5% 6% 47%	2049
	21st to end	Day	16% 6% 2 4 2 2 3 3 4 5% 52%	1730
March	1st to 10th	Day	11% 7% 2 6% 3 3 3 3 4 6% 52%	4971
	11th to 20th	Day	13% 6% 2 5% 4 3 3 2 4 5% 53%	5090
	21st to end	Day	12% 7% 3 6% 4 4 4 3 5% 7% 48%	5583
April	1st to 10th	Day	13% 7% 3 7% 5% 4 4 3 5% 6% 44%	2310
	11th to 20th	Day	16% 8% 2 6% 4 4 4 3 5% 5% 42%	2302
	21st to end	Day	13% 6% 1 6% 5% 5% 4 4 5% 6% 44%	2677
May	1st to 10th	Day	18% 7% 3 6% 4 3 4 4 6% 7% 37%	7617
	11th to 20th	Day	10% 7% 3 7% 5% 4 4 4 6% 8% 44%	7627
	21st to end	Day	12% 6% 3 7% 5% 5% 6% 5% 7% 9% 35%	8392
June	1st to 10th	Day	5% 4 2 5% 3 5% 7% 5% 7% 9% 48%	2730
	11th to 20th	Day	6% 4 2 5% 4 5% 5% 5% 7% 9% 50%	2666
	21st to end	Day	6% 5% 2 5% 5% 4 5% 6% 8% 10% 44%	2600
July	1st to 10th	Day	11% 6% 2 6% 5% 5% 5% 4 6% 9% 39%	5900
	11th to 20th	Day	4 3 1 5% 4 5% 6% 5% 8% 11% 49%	5900
	21st to end	Day	6% 5% 2 6% 4 5% 4 5% 7% 10% 46%	6422
August	1st to 10th	Day	1 1 1 2 2 2 2 2 5% 9% 72%	4215
	11th to 20th	Day	3 3 1 4 3 3 4 4 6% 9% 61%	3846
	21st to end	Day	4 3 2 4 4 4 5% 5% 8% 11% 50%	4151
September	1st to 10th	Day	9% 6% 2 6% 4 4 5% 4 5% 7% 48%	2200
	11th to 20th	Day	9% 5% 2 6% 5% 5% 5% 4 6% 8% 45%	2200
	21st to end	Day	7% 3 1 6% 3 4 5% 4 6% 8% 53%	2200
October	1st to 10th	Day	6% 4 1 3 3 4 4 4 5% 7% 59%	2200
	11th to 20th	Day	11% 4 2 4 3 3 4 3 4 6% 56%	2070
	21st to end	Day	10% 3 2 5% 3 3 3 3 4 5% 60%	2200
November	1st to 10th	Day	13% 8% 2 5% 4 3 3 3 4 6% 49%	2058
	11th to 20th	Day	9% 5% 2 6% 3 3 4 3 4 6% 53%	1943
	21st to end	Day	15% 6% 3 6% 4 3 3 3 4 5% 48%	1890
December	1st to 10th	Day	23% 7% 3 5% 4 3 3 2 4 5% 42%	3030
	11th to 20th	Day	12% 8% 2 6% 5% 4 4 4 5% 5% 44%	3481
	21st to end	Day	10% 6% 2 5% 3 3 3 3 3 4 59%	4587
January	1st to 10th	Night	13% 7% 2 4 3 2 2 2 3 5% 56%	7634
	11th to 20th	Night	9% 3 1 3 2 2 3 3 5% 5% 65%	7680
	21st to end	Night	25% 9% 2 5% 3 3 3 2 4 5% 40%	8027
February	1st to 10th	Night	14% 7% 2 5% 3 3 3 2 3 6% 51%	2520
	11th to 20th	Night	16% 6% 2 5% 3 3 3 3 4 5% 51%	2458
	21st to end	Night	15% 7% 1 5% 3 3 3 3 4 6% 50%	2076
March	1st to 10th	Night	11% 7% 2 6% 4 4 4 4 5% 7% 47%	5105
	11th to 20th	Night	13% 6% 2 5% 3 3 3 3 4 5% 53%	5090
	21st to end	Night	12% 7% 3 6% 4 4 4 3 4 6% 48%	5588
April	1st to 10th	Night	10% 6% 2 5% 4 4 5% 4 5% 8% 47%	2310
	11th to 20th	Night	14% 6% 2 7% 4 3 4 3 5% 6% 46%	2261
	21st to end	Night	15% 6% 3 5% 4 4 4 3 4 6% 47%	1940
May	1st to 10th	Night	20% 9% 3 5% 3 3 4 3 5% 7% 39%	5266
	11th to 20th	Night	8% 6% 2 7% 5% 4 4 4 7% 7% 46%	5265
	21st to end	Night	12% 7% 2 7% 4 4 5% 4 7% 10% 38%	5793
June	1st to 10th	Night	3 3 2 5% 3 2 4 3 6% 9% 60%	1890
	11th to 20th	Night	4 3 1 3 3 3 4 4 6% 10% 59%	1845
	21st to end	Night	6% 3 1 3 3 4 4 4 6% 9% 57%	1800
July	1st to 10th	Night	9% 6% 3 6% 4 4 4 4 8% 9% 44%	4078
	11th to 20th	Night	3 2 1 3 3 4 5% 5% 8% 12% 55%	4077
	21st to end	Night	3 4 1 5% 4 4 5% 5% 8% 11% 49%	4449
August	1st to 10th	Night	1 1 1 1 1 2 3 2 5% 8% 76%	2926
	11th to 20th	Night	3 2 1 3 3 3 4 3 7% 10% 63%	3213
	21st to end	Night	4 3 1 3 3 3 5% 4 7% 11% 57%	3752
September	1st to 10th	Night	8% 5% 2 4 4 4 4 3 6% 7% 54%	2200
	11th to 20th	Night	9% 5% 2 5% 4 4 5% 4 6% 8% 48%	2200
	21st to end	Night	8% 3 1 4 3 3 4 4 5% 8% 55%	2200
October	1st to 10th	Night	4 3 1 4 2 3 3 3 5% 6% 66%	2200
	11th to 20th	Night	11% 4 2 4 2 2 3 3 4 6% 59%	2309
	21st to end	Night	11% 5% 1 3 3 3 2 2 4 5% 61%	2640
November	1st to 10th	Night	11% 6% 2 5% 3 3 3 2 3 5% 56%	2460
	11th to 20th	Night	8% 5% 2 4 2 3 3 3 5% 7% 58%	2672
	21st to end	Night	15% 5% 2 5% 4 4 4 3 4 6% 49%	2730
December	1st to 10th	Night	19% 8% 2 6% 3 3 4 3 4 5% 43%	4380
	11th to 20th	Night	13% 9% 3 6% 4 3 3 3 4 4 48%	4946
	21st to end	Night	12% 7% 2 5% 2 2 3 2 3 4 59%	6633

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	35% 3 5% 24% 24% 10%	5290
	11th to 20th	Day	32% 2 4 15% 26% 21%	5310
	21st to end	Day	48% 3 4 12% 22% 11%	6229
February	1st to 10th	Day	40% 4 5% 13% 20% 18%	2100
	11th to 20th	Day	39% 4 9% 18% 19% 13%	2059
	21st to end	Day	36% 4 5% 17% 22% 16%	1730
March	1st to 10th	Day	34% 3 5% 17% 17% 23%	4971
	11th to 20th	Day	36% 4 5% 9% 15% 31%	5090
	21st to end	Day	37% 4 8% 19% 21% 11%	5585
April	1st to 10th	Day	41% 5% 8% 16% 16% 13%	2310
	11th to 20th	Day	43% 5% 8% 14% 18% 11%	2302
	21st to end	Day	39% 5% 7% 21% 17% 9%	2677
May	1st to 10th	Day	45% 6% 11% 20% 15% 3	7655
	11th to 20th	Day	38% 5% 9% 17% 23% 7%	7631
	21st to end	Day	41% 8% 12% 25% 12% 2	8405
June	1st to 10th	Day	29% 8% 13% 29% 18% 4	2730
	11th to 20th	Day	30% 6% 13% 27% 19% 5%	2666
	21st to end	Day	33% 9% 12% 25% 17% 4	2600
July	1st to 10th	Day	40% 7% 18% 28% 6% 1	5836
	11th to 20th	Day	26% 9% 16% 32% 15% 2	5831
	21st to end	Day	30% 8% 17% 27% 17% 2	6240
August	1st to 10th	Day	12% 4 11% 40% 32% 1	4201
	11th to 20th	Day	20% 5% 22% 39% 12% 2	3882
	21st to end	Day	25% 10% 18% 25% 19% 2	4150
September	1st to 10th	Day	36% 6% 10% 23% 17% 10%	2200
	11th to 20th	Day	36% 7% 11% 21% 19% 6%	2200
	21st to end	Day	29% 6% 10% 21% 19% 14%	2200
October	1st to 10th	Day	16% 3 7% 12% 25% 36%	3590
	11th to 20th	Day	20% 4 8% 19% 27% 22%	3349
	21st to end	Day	23% 4 5% 19% 35% 14%	3538
November	1st to 10th	Day	37% 4 7% 17% 22% 12%	2058
	11th to 20th	Day	32% 5% 7% 18% 22% 16%	1943
	21st to end	Day	39% 4 6% 17% 20% 14%	1890
December	1st to 10th	Day	48% 2 6% 16% 19% 9%	3030
	11th to 20th	Day	40% 6% 7% 12% 23% 13%	3479
	21st to end	Day	30% 3 4 17% 27% 19%	4587
January	1st to 10th	Night	33% 3 5% 19% 26% 14%	7635
	11th to 20th	Night	23% 2 4 18% 29% 24%	7680
	21st to end	Night	49% 3 3 11% 21% 14%	8027
February	1st to 10th	Night	37% 4 6% 13% 22% 19%	2520
	11th to 20th	Night	38% 3 8% 17% 19% 16%	2458
	21st to end	Night	38% 4 6% 14% 21% 18%	2076
March	1st to 10th	Night	37% 4 7% 18% 19% 15%	5105
	11th to 20th	Night	36% 4 7% 11% 15% 27%	5090
	21st to end	Night	38% 5% 7% 18% 21% 11%	5588
April	1st to 10th	Night	35% 6% 10% 17% 16% 15%	2310
	11th to 20th	Night	39% 7% 9% 14% 17% 14%	2261
	21st to end	Night	40% 4 10% 19% 17% 9%	1940
May	1st to 10th	Night	46% 5% 10% 18% 15% 6%	5293
	11th to 20th	Night	36% 6% 11% 18% 19% 10%	5266
	21st to end	Night	39% 8% 17% 25% 8% 3	5805
June	1st to 10th	Night	21% 8% 16% 31% 21% 3	1890
	11th to 20th	Night	20% 7% 17% 29% 22% 5%	1845
	21st to end	Night	23% 7% 19% 29% 17% 4	1800
July	1st to 10th	Night	34% 8% 25% 27% 5% 1	4035
	11th to 20th	Night	20% 8% 23% 35% 13% 1	4026
	21st to end	Night	26% 9% 23% 26% 13% 4	4320
August	1st to 10th	Night	8% 5% 14% 42% 31% 1	2916
	11th to 20th	Night	17% 6% 29% 34% 12% 2	3243
	21st to end	Night	21% 11% 21% 26% 19% 2	3752
September	1st to 10th	Night	29% 7% 13% 23% 19% 8%	2200
	11th to 20th	Night	33% 7% 14% 25% 15% 6%	2200
	21st to end	Night	26% 7% 13% 23% 18% 13%	2200
October	1st to 10th	Night	13% 3 8% 16% 22% 38%	3590
	11th to 20th	Night	19% 4 9% 18% 29% 21%	3756
	21st to end	Night	21% 4 6% 19% 34% 17%	4252
November	1st to 10th	Night	31% 4 8% 18% 23% 14%	2460
	11th to 20th	Night	28% 4 9% 21% 21% 17%	2672
	21st to end	Night	37% 3 10% 16% 20% 15%	2730
December	1st to 10th	Night	45% 3 7% 16% 18% 11%	4380
	11th to 20th	Night	40% 4 6% 10% 23% 17%	4947
	21st to end	Night	32% 3 4 17% 28% 17%	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	18% 18% 35% 22% 5% 1	330
	11th to 20th	Day	22% 15% 32% 24% 7%	330
	21st to end	Day	20% 18% 34% 21% 6%	363
February	1st to 10th	Day	27% 14% 31% 21% 7%	330
	11th to 20th	Day	22% 18% 37% 19% 3	330
	21st to end	Day	26% 16% 40% 16% 2	273
March	1st to 10th	Day	20% 15% 44% 18% 3	330
	11th to 20th	Day	19% 21% 35% 20% 4	330
	21st to end	Day	15% 16% 41% 21% 5% 1	363
April	1st to 10th	Day	17% 18% 43% 17% 5%	330
	11th to 20th	Day	19% 20% 37% 18% 6%	340
	21st to end	Day	18% 16% 40% 20% 6%	697
May	1st to 10th	Day	16% 12% 40% 26% 6%	753
	11th to 20th	Day	16% 10% 35% 28% 9% 1	775
	21st to end	Day	12% 7% 30% 36% 13% 2	844
June	1st to 10th	Day	5% 4 22% 42% 24% 4	780
	11th to 20th	Day	7% 3 18% 51% 19% 2	756
	21st to end	Day	5% 2 15% 41% 30% 7%	730
July	1st to 10th	Day	7% 4 10% 37% 32% 10%	721
	11th to 20th	Day	4 1 7% 41% 40% 7%	718
	21st to end	Day	4 2 5% 36% 43% 10%	794
August	1st to 10th	Day	2 5% 35% 44% 13%	720
	11th to 20th	Day	6% 1 5% 39% 36% 13%	517
	21st to end	Day	4 1 6% 31% 38% 21%	487
September	1st to 10th	Day	8% 2 7% 28% 38% 17%	330
	11th to 20th	Day	6% 1 6% 30% 42% 15%	330
	21st to end	Day	9% 1 9% 32% 38% 11%	330
October	1st to 10th	Day	5% 2 14% 36% 35% 10%	330
	11th to 20th	Day	11% 3 26% 36% 18% 5%	330
	21st to end	Day	20% 7% 29% 24% 17% 4	363
November	1st to 10th	Day	18% 7% 27% 34% 10% 4	330
	11th to 20th	Day	14% 8% 31% 32% 11% 3	330
	21st to end	Day	21% 17% 33% 18% 8% 2	330
December	1st to 10th	Day	20% 9% 34% 25% 9% 3	330
	11th to 20th	Day	18% 16% 32% 22% 8% 2	330
	21st to end	Day	15% 14% 36% 28% 6% 2	363
January	1st to 10th	Night	17% 10% 34% 32% 6%	1050
	11th to 20th	Night	19% 11% 34% 32% 5%	1050
	21st to end	Night	20% 11% 33% 30% 6%	1024
February	1st to 10th	Night	20% 11% 35% 29% 5%	840
	11th to 20th	Night	22% 12% 39% 25% 3	824
	21st to end	Night	19% 14% 43% 23% 1	692
March	1st to 10th	Night	19% 13% 40% 25% 3	669
	11th to 20th	Night	16% 13% 39% 28% 4	630
	21st to end	Night	14% 13% 44% 26% 3	693
April	1st to 10th	Night	14% 10% 44% 30% 2	630
	11th to 20th	Night	17% 13% 41% 25% 3	623
	21st to end	Night	17% 10% 44% 22% 6%	630
May	1st to 10th	Night	15% 11% 41% 28% 5%	630
	11th to 20th	Night	11% 9% 37% 32% 11%	621
	21st to end	Night	10% 7% 36% 36% 11%	683
June	1st to 10th	Night	4 2 27% 48% 18% 1	630
	11th to 20th	Night	4 2 34% 47% 12% 1	615
	21st to end	Night	4 2 20% 50% 21% 3	600
July	1st to 10th	Night	10% 2 12% 48% 25% 3	585
	11th to 20th	Night	4 12% 56% 26% 2	582
	21st to end	Night	4 1 10% 53% 29% 3	657
August	1st to 10th	Night	1 9% 56% 31% 3	597
	11th to 20th	Night	4 2 8% 54% 29% 3	594
	21st to end	Night	5% 1 4 47% 37% 5%	660
September	1st to 10th	Night	8% 2 9% 44% 32% 4	600
	11th to 20th	Night	10% 2 8% 42% 36% 4	600
	21st to end	Night	10% 1 13% 41% 33% 2	600
October	1st to 10th	Night	6% 2 13% 46% 30% 3	600
	11th to 20th	Night	11% 4 24% 41% 19% 2	709
	21st to end	Night	13% 9% 28% 30% 19% 1	880
November	1st to 10th	Night	12% 6% 24% 41% 15% 1	820
	11th to 20th	Night	11% 6% 30% 39% 13% 1	992
	21st to end	Night	15% 10% 34% 30% 10% 1	1050
December	1st to 10th	Night	17% 8% 30% 35% 8% 1	1050
	11th to 20th	Night	21% 8% 30% 32% 8%	1050
	21st to end	Night	17% 10% 32% 34% 7%	1155

Page generated at 2026-06-13 01:31:40. Version ac07

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