Uvalde
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Uvalde clear sky chart from 2005-11-06 to 2024-12-24.

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% 5% 2 5% 4 4 4 3 5% 7% 50%	101372
	Night	11% 5% 2 4 3 3 3 3 5% 7% 54%	98851
Transparency	Day	33% 5% 10% 22% 20% 11%	105283
	Night	29% 5% 11% 21% 20% 14%	103067
Seeing	Day	13% 5% 18% 32% 25% 6%	14833
	Night	13% 5% 23% 42% 16% 1	24872

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	12% 6% 2 3 2 2 2 2 3 5% 61%	2847
	11th to 20th	Day	14% 5% 1 3 2 2 2 2 4 5% 58%	3024
	21st to end	Day	16% 6% 2 5% 3 3 3 2 4 9% 45%	3487
February	1st to 10th	Day	16% 8% 2 5% 3 2 3 3 4 5% 48%	1900
	11th to 20th	Day	16% 6% 3 5% 3 3 3 3 5% 6% 47%	1849
	21st to end	Day	15% 6% 1 3 3 3 3 3 4 6% 53%	1570
March	1st to 10th	Day	17% 8% 2 5% 4 2 3 2 4 6% 46%	3236
	11th to 20th	Day	23% 9% 3 7% 4 3 3 2 4 5% 37%	3480
	21st to end	Day	16% 5% 2 4 3 3 3 3 5% 6% 50%	3814
April	1st to 10th	Day	14% 7% 2 5% 4 3 3 3 5% 7% 47%	2090
	11th to 20th	Day	16% 5% 2 4 4 4 3 3 5% 5% 49%	2241
	21st to end	Day	16% 6% 2 6% 5% 3 3 3 4 5% 47%	2280
May	1st to 10th	Day	22% 6% 2 6% 4 3 3 3 5% 7% 39%	4068
	11th to 20th	Day	14% 6% 2 5% 4 5% 4 3 5% 8% 45%	4082
	21st to end	Day	11% 5% 2 6% 5% 5% 5% 4 6% 9% 43%	4477
June	1st to 10th	Day	6% 4 2 3 3 4 4 4 7% 10% 53%	2470
	11th to 20th	Day	7% 4 2 4 3 4 5% 4 6% 8% 52%	2470
	21st to end	Day	6% 5% 2 5% 6% 6% 6% 4 7% 9% 43%	2470
July	1st to 10th	Day	8% 5% 2 5% 5% 3 4 3 5% 8% 52%	4120
	11th to 20th	Day	6% 4 1 5% 4 4 5% 4 6% 10% 51%	4120
	21st to end	Day	6% 5% 2 5% 4 5% 5% 5% 7% 11% 46%	4341
August	1st to 10th	Day	1 1 1 2 2 2 3 2 5% 8% 71%	3785
	11th to 20th	Day	3 2 1 3 3 3 3 4 6% 10% 63%	3726
	21st to end	Day	6% 3 1 4 4 5% 5% 4 6% 10% 52%	4162
September	1st to 10th	Day	10% 7% 3 6% 6% 5% 6% 4 5% 7% 41%	2090
	11th to 20th	Day	11% 6% 3 5% 6% 4 4 4 6% 9% 43%	2090
	21st to end	Day	9% 4 2 5% 4 4 6% 4 5% 8% 50%	2090
October	1st to 10th	Day	8% 4 2 4 3 4 4 3 5% 8% 56%	2090
	11th to 20th	Day	14% 5% 2 4 3 3 3 3 4 6% 51%	2090
	21st to end	Day	13% 5% 1 3 3 3 3 2 4 4 58%	2097
November	1st to 10th	Day	17% 7% 2 5% 4 3 3 3 4 6% 45%	1903
	11th to 20th	Day	16% 6% 2 4 3 3 4 3 4 5% 51%	1800
	21st to end	Day	18% 6% 2 6% 3 3 4 2 3 4 49%	1800
December	1st to 10th	Day	19% 8% 3 5% 3 2 2 3 4 5% 47%	1800
	11th to 20th	Day	18% 7% 2 6% 3 4 3 3 3 5% 45%	2251
	21st to end	Day	15% 6% 2 4 3 3 2 2 4 5% 55%	3162
January	1st to 10th	Night	14% 4 1 4 2 2 2 2 3 6% 58%	4108
	11th to 20th	Night	11% 3 1 3 2 2 2 2 2 4 68%	3961
	21st to end	Night	19% 7% 2 4 3 3 3 2 4 6% 47%	4180
February	1st to 10th	Night	13% 6% 1 4 2 3 2 2 4 6% 56%	2280
	11th to 20th	Night	17% 7% 1 3 3 3 3 2 3 6% 54%	2218
	21st to end	Night	13% 6% 2 4 4 3 4 3 4 7% 51%	1884
March	1st to 10th	Night	12% 7% 2 5% 4 4 4 3 5% 7% 47%	3622
	11th to 20th	Night	18% 8% 3 8% 3 3 4 3 4 5% 42%	3480
	21st to end	Night	12% 5% 1 5% 3 3 3 3 5% 7% 51%	3817
April	1st to 10th	Night	10% 5% 1 4 3 3 3 4 7% 7% 52%	2090
	11th to 20th	Night	15% 5% 2 6% 3 3 4 3 4 6% 49%	1884
	21st to end	Night	15% 6% 2 5% 4 3 2 3 4 6% 50%	1900
May	1st to 10th	Night	17% 6% 2 5% 3 3 3 3 5% 6% 47%	2833
	11th to 20th	Night	12% 4 2 5% 3 3 3 3 5% 7% 54%	2823
	21st to end	Night	9% 4 2 5% 3 4 3 3 5% 8% 52%	3090
June	1st to 10th	Night	3 3 1 2 3 2 4 3 5% 10% 64%	1710
	11th to 20th	Night	4 2 1 4 4 4 4 4 6% 10% 58%	1710
	21st to end	Night	5% 4 1 5% 3 4 4 4 6% 10% 53%	1710
July	1st to 10th	Night	4 4 1 4 3 3 3 3 5% 9% 59%	2850
	11th to 20th	Night	3 4 1 4 4 4 5% 5% 7% 9% 54%	2850
	21st to end	Night	9% 3 1 4 4 4 5% 4 6% 10% 49%	3216
August	1st to 10th	Night	1 1 2 2 2 3 2 4 8% 75%	3155
	11th to 20th	Night	3 2 1 3 2 3 3 3 5% 10% 64%	3113
	21st to end	Night	5% 3 1 5% 4 4 4 4 6% 10% 54%	3503
September	1st to 10th	Night	8% 5% 2 6% 5% 5% 5% 4 6% 8% 47%	2090
	11th to 20th	Night	10% 6% 2 6% 4 4 4 4 5% 9% 47%	2090
	21st to end	Night	9% 5% 2 5% 3 4 4 3 5% 8% 52%	2090
October	1st to 10th	Night	7% 4 1 3 3 3 3 3 4 7% 62%	2090
	11th to 20th	Night	13% 4 2 3 3 3 3 3 4 6% 57%	2090
	21st to end	Night	12% 3 1 3 2 2 2 2 3 5% 66%	2479
November	1st to 10th	Night	14% 6% 1 4 3 3 2 2 4 5% 55%	2391
	11th to 20th	Night	11% 5% 2 5% 3 3 3 3 4 5% 57%	2600
	21st to end	Night	16% 5% 2 4 3 3 3 4 4 6% 51%	2600
December	1st to 10th	Night	17% 6% 2 4 3 3 3 3 4 6% 50%	2600
	11th to 20th	Night	17% 6% 2 5% 3 3 3 2 3 5% 49%	3166
	21st to end	Night	16% 4 2 4 2 3 2 2 5% 7% 53%	4578

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	28% 2 4 15% 28% 24%	2848
	11th to 20th	Day	29% 2 5% 16% 25% 23%	3024
	21st to end	Day	38% 4 7% 15% 26% 10%	3487
February	1st to 10th	Day	40% 3 6% 13% 19% 20%	1900
	11th to 20th	Day	38% 3 6% 16% 21% 15%	1859
	21st to end	Day	33% 4 8% 17% 21% 17%	1570
March	1st to 10th	Day	42% 4 6% 14% 19% 14%	3236
	11th to 20th	Day	50% 5% 7% 10% 16% 13%	3480
	21st to end	Day	34% 4 9% 16% 16% 21%	3814
April	1st to 10th	Day	37% 4 8% 16% 18% 16%	2090
	11th to 20th	Day	36% 6% 7% 19% 17% 16%	2241
	21st to end	Day	38% 4 6% 19% 17% 15%	2280
May	1st to 10th	Day	44% 5% 9% 18% 14% 10%	4106
	11th to 20th	Day	37% 6% 9% 21% 17% 9%	4086
	21st to end	Day	35% 7% 11% 30% 15% 2	4489
June	1st to 10th	Day	22% 8% 14% 30% 21% 5%	2470
	11th to 20th	Day	27% 7% 13% 27% 19% 7%	2470
	21st to end	Day	34% 7% 14% 23% 17% 4	2470
July	1st to 10th	Day	30% 5% 15% 36% 12% 1	4056
	11th to 20th	Day	28% 6% 18% 30% 16% 2	4051
	21st to end	Day	29% 7% 17% 30% 16% 1	4204
August	1st to 10th	Day	12% 4 11% 41% 29% 2	3772
	11th to 20th	Day	17% 5% 19% 43% 13% 2	3762
	21st to end	Day	26% 7% 17% 25% 22% 2	4161
September	1st to 10th	Day	41% 7% 11% 18% 16% 6%	2090
	11th to 20th	Day	37% 7% 12% 21% 18% 5%	2090
	21st to end	Day	31% 8% 10% 21% 18% 12%	2090
October	1st to 10th	Day	17% 4 6% 13% 22% 38%	3480
	11th to 20th	Day	32% 3 7% 15% 19% 24%	3458
	21st to end	Day	28% 3 5% 15% 36% 14%	3435
November	1st to 10th	Day	40% 5% 7% 18% 18% 12%	1903
	11th to 20th	Day	36% 3 8% 17% 19% 17%	1800
	21st to end	Day	41% 3 5% 19% 18% 15%	1800
December	1st to 10th	Day	41% 4 7% 16% 21% 11%	1800
	11th to 20th	Day	42% 3 7% 10% 19% 18%	2249
	21st to end	Day	34% 3 4 15% 31% 13%	3162
January	1st to 10th	Night	28% 2 6% 13% 25% 25%	4108
	11th to 20th	Night	23% 2 4 18% 24% 29%	3961
	21st to end	Night	40% 2 5% 13% 25% 13%	4180
February	1st to 10th	Night	31% 3 7% 16% 19% 23%	2280
	11th to 20th	Night	35% 3 6% 18% 19% 19%	2218
	21st to end	Night	34% 4 7% 15% 21% 19%	1884
March	1st to 10th	Night	36% 6% 9% 16% 18% 15%	3622
	11th to 20th	Night	45% 5% 8% 14% 13% 15%	3480
	21st to end	Night	31% 6% 12% 19% 17% 17%	3817
April	1st to 10th	Night	29% 6% 11% 19% 18% 17%	2090
	11th to 20th	Night	36% 4 10% 16% 15% 19%	1884
	21st to end	Night	36% 4 10% 20% 16% 15%	1900
May	1st to 10th	Night	36% 6% 11% 20% 16% 12%	2860
	11th to 20th	Night	30% 7% 11% 20% 21% 11%	2824
	21st to end	Night	28% 7% 13% 29% 18% 6%	3099
June	1st to 10th	Night	16% 6% 17% 33% 24% 3	1710
	11th to 20th	Night	20% 6% 12% 29% 26% 7%	1710
	21st to end	Night	25% 9% 17% 26% 18% 5%	1710
July	1st to 10th	Night	23% 5% 21% 38% 11% 1	2805
	11th to 20th	Night	24% 8% 20% 27% 18% 2	2796
	21st to end	Night	27% 7% 21% 31% 13% 1	3114
August	1st to 10th	Night	10% 4 14% 43% 26% 2	3144
	11th to 20th	Night	16% 6% 27% 39% 11% 2	3143
	21st to end	Night	25% 9% 19% 27% 18% 2	3503
September	1st to 10th	Night	33% 9% 14% 19% 17% 8%	2090
	11th to 20th	Night	35% 7% 16% 20% 17% 5%	2090
	21st to end	Night	29% 6% 12% 22% 18% 13%	2090
October	1st to 10th	Night	17% 4 6% 16% 21% 36%	3480
	11th to 20th	Night	25% 4 8% 15% 23% 26%	3460
	21st to end	Night	21% 2 7% 17% 37% 17%	4079
November	1st to 10th	Night	32% 4 7% 18% 24% 15%	2391
	11th to 20th	Night	30% 4 9% 18% 22% 18%	2600
	21st to end	Night	35% 4 8% 18% 18% 17%	2600
December	1st to 10th	Night	36% 4 7% 19% 19% 15%	2600
	11th to 20th	Night	39% 3 6% 15% 19% 19%	3167
	21st to end	Night	32% 4 6% 16% 25% 17%	4578

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	19% 9% 27% 33% 12%	270
	11th to 20th	Day	18% 8% 22% 36% 14% 1	270
	21st to end	Day	16% 6% 31% 32% 14%	297
February	1st to 10th	Day	24% 10% 23% 26% 16% 1	270
	11th to 20th	Day	21% 8% 34% 26% 9% 3	270
	21st to end	Day	24% 10% 36% 22% 8%	225
March	1st to 10th	Day	22% 11% 36% 25% 6%	270
	11th to 20th	Day	19% 10% 40% 22% 10%	270
	21st to end	Day	21% 11% 34% 28% 5%	297
April	1st to 10th	Day	15% 11% 35% 31% 8%	270
	11th to 20th	Day	12% 14% 37% 29% 8%	439
	21st to end	Day	12% 10% 40% 31% 7%	460
May	1st to 10th	Day	20% 7% 29% 35% 9% 1	639
	11th to 20th	Day	19% 7% 27% 34% 12% 1	675
	21st to end	Day	16% 4 27% 39% 13% 1	734
June	1st to 10th	Day	5% 3 16% 45% 25% 6%	680
	11th to 20th	Day	8% 2 13% 49% 24% 4	680
	21st to end	Day	8% 2 10% 35% 37% 8%	680
July	1st to 10th	Day	10% 3 6% 32% 40% 9%	671
	11th to 20th	Day	5% 1 3 29% 52% 10%	668
	21st to end	Day	3 1 6% 34% 45% 12%	664
August	1st to 10th	Day	2 1 2 32% 49% 15%	487
	11th to 20th	Day	7% 5% 27% 46% 14%	477
	21st to end	Day	5% 1 4 29% 40% 19%	534
September	1st to 10th	Day	11% 5% 22% 40% 22%	300
	11th to 20th	Day	5% 1 3 21% 47% 23%	300
	21st to end	Day	10% 4 18% 49% 18%	300
October	1st to 10th	Day	8% 3 10% 28% 39% 12%	300
	11th to 20th	Day	12% 3 9% 41% 27% 8%	300
	21st to end	Day	18% 8% 20% 28% 21% 5%	330
November	1st to 10th	Day	19% 6% 20% 29% 21% 5%	300
	11th to 20th	Day	24% 7% 15% 30% 20% 5%	300
	21st to end	Day	22% 9% 27% 26% 13% 3	300
December	1st to 10th	Day	24% 4 20% 30% 18% 4	300
	11th to 20th	Day	24% 7% 20% 33% 15% 1	300
	21st to end	Day	20% 6% 24% 33% 15% 3	306
January	1st to 10th	Night	17% 4 23% 43% 12% 1	950
	11th to 20th	Night	17% 5% 25% 44% 9%	856
	21st to end	Night	20% 7% 24% 41% 8%	836
February	1st to 10th	Night	18% 7% 27% 39% 8% 1	760
	11th to 20th	Night	21% 7% 31% 34% 7%	744
	21st to end	Night	16% 7% 36% 38% 3	628
March	1st to 10th	Night	18% 9% 36% 31% 6%	700
	11th to 20th	Night	15% 10% 34% 36% 4	570
	21st to end	Night	14% 9% 43% 29% 5%	627
April	1st to 10th	Night	11% 8% 42% 36% 3	570
	11th to 20th	Night	16% 9% 44% 29% 2	563
	21st to end	Night	13% 10% 41% 32% 4	570
May	1st to 10th	Night	10% 7% 44% 35% 3	570
	11th to 20th	Night	13% 6% 35% 38% 7%	561
	21st to end	Night	11% 4 36% 40% 8%	617
June	1st to 10th	Night	4 3 26% 52% 14% 1	570
	11th to 20th	Night	3 2 28% 56% 11%	570
	21st to end	Night	6% 2 18% 54% 19% 1	570
July	1st to 10th	Night	8% 3 9% 55% 24% 1	555
	11th to 20th	Night	3 1 10% 54% 31% 1	552
	21st to end	Night	4 2 9% 54% 31%	624
August	1st to 10th	Night	1 7% 53% 37% 1	567
	11th to 20th	Night	6% 1 7% 51% 33% 2	564
	21st to end	Night	6% 2 7% 45% 38% 3	627
September	1st to 10th	Night	8% 1 6% 46% 36% 3	570
	11th to 20th	Night	10% 1 7% 43% 34% 4	570
	21st to end	Night	10% 1 10% 40% 33% 5%	570
October	1st to 10th	Night	6% 2 10% 50% 31% 1	570
	11th to 20th	Night	15% 3 17% 42% 21% 2	570
	21st to end	Night	11% 5% 20% 39% 23% 2	807
November	1st to 10th	Night	15% 4 16% 36% 26% 3	831
	11th to 20th	Night	13% 4 18% 44% 21% 2	1000
	21st to end	Night	17% 4 21% 41% 16% 1	1000
December	1st to 10th	Night	20% 4 17% 42% 16% 2	1000
	11th to 20th	Night	23% 6% 19% 39% 13% 1	1000
	21st to end	Night	17% 5% 22% 45% 11% 1	1063

Page generated at 2024-12-21 03:13:47. Version ac07

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