Eagle Pass
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Eagle Pass clear sky chart from 2005-11-06 to 2024-11-05.

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	10% 5% 2 5% 3 3 4 3 5% 7% 53%	100787
	Night	10% 4 2 4 3 3 3 3 5% 7% 56%	98381
Transparency	Day	30% 5% 10% 22% 21% 13%	104740
	Night	27% 5% 10% 21% 21% 15%	102542
Seeing	Day	11% 5% 19% 34% 26% 7%	14598
	Night	11% 4 22% 45% 17% 1	24575

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% 6% 2 3 3 2 2 2 3 5% 62%	2853
	11th to 20th	Day	10% 7% 2 3 2 2 2 3 5% 5% 61%	3170
	21st to end	Day	12% 7% 2 5% 4 4 3 3 6% 8% 45%	3487
February	1st to 10th	Day	11% 6% 2 6% 3 3 4 3 4 7% 50%	1900
	11th to 20th	Day	13% 7% 2 3 3 3 3 3 4 7% 52%	1849
	21st to end	Day	11% 4 1 4 3 3 3 3 6% 6% 56%	1570
March	1st to 10th	Day	14% 7% 2 5% 4 3 4 3 5% 6% 46%	3156
	11th to 20th	Day	21% 8% 3 6% 4 3 3 3 4 6% 40%	3480
	21st to end	Day	10% 5% 2 4 3 3 4 3 5% 7% 54%	3814
April	1st to 10th	Day	11% 6% 2 4 4 3 4 3 5% 7% 50%	2159
	11th to 20th	Day	12% 5% 2 4 3 4 3 3 5% 7% 51%	2254
	21st to end	Day	13% 6% 2 5% 3 3 3 3 5% 7% 50%	2280
May	1st to 10th	Day	18% 6% 2 5% 3 3 3 3 5% 8% 43%	3923
	11th to 20th	Day	12% 5% 2 6% 4 4 4 3 5% 8% 48%	4082
	21st to end	Day	10% 5% 2 5% 4 4 4 4 6% 10% 44%	4477
June	1st to 10th	Day	4 3 1 4 3 3 4 4 7% 10% 57%	2470
	11th to 20th	Day	4 3 1 4 3 3 4 4 6% 9% 57%	2470
	21st to end	Day	5% 4 2 5% 6% 5% 6% 5% 6% 9% 49%	2470
July	1st to 10th	Day	7% 4 2 4 4 4 4 4 5% 7% 55%	4120
	11th to 20th	Day	6% 5% 1 4 3 4 4 4 6% 10% 53%	4120
	21st to end	Day	7% 4 1 4 4 4 4 4 6% 10% 51%	4124
August	1st to 10th	Day	1 1 1 1 2 2 2 2 4 7% 78%	3785
	11th to 20th	Day	2 2 1 3 2 3 3 3 5% 8% 69%	3726
	21st to end	Day	4 3 1 4 3 3 4 4 7% 10% 57%	4180
September	1st to 10th	Day	10% 6% 2 6% 6% 4 5% 4 6% 8% 43%	2124
	11th to 20th	Day	12% 6% 2 6% 4 5% 5% 5% 6% 7% 42%	2090
	21st to end	Day	8% 4 2 5% 3 4 4 4 6% 8% 52%	2090
October	1st to 10th	Day	8% 4 2 4 3 3 4 3 4 7% 58%	2090
	11th to 20th	Day	13% 6% 2 5% 4 4 3 3 4 7% 50%	2090
	21st to end	Day	13% 5% 1 4 2 2 2 2 3 4 62%	2163
November	1st to 10th	Day	15% 6% 2 6% 3 3 3 2 5% 6% 50%	1795
	11th to 20th	Day	13% 5% 2 4 3 4 4 3 4 6% 52%	1710
	21st to end	Day	15% 7% 2 5% 3 3 3 3 4 5% 50%	1710
December	1st to 10th	Day	17% 7% 3 5% 3 2 2 2 4 5% 49%	1710
	11th to 20th	Day	14% 7% 3 5% 4 4 3 3 4 7% 47%	2161
	21st to end	Day	13% 6% 2 5% 3 3 3 2 4 5% 55%	3135
January	1st to 10th	Night	10% 4 2 4 2 2 2 2 5% 7% 59%	4108
	11th to 20th	Night	9% 4 1 3 2 2 2 2 2 4 69%	3822
	21st to end	Night	16% 6% 2 6% 3 3 2 3 5% 6% 48%	4180
February	1st to 10th	Night	10% 5% 2 4 3 3 3 3 5% 5% 57%	2280
	11th to 20th	Night	14% 6% 1 4 2 2 3 2 4 6% 56%	2218
	21st to end	Night	10% 5% 2 4 3 4 4 3 5% 6% 55%	1884
March	1st to 10th	Night	11% 5% 1 4 3 4 4 4 5% 8% 51%	3706
	11th to 20th	Night	19% 6% 2 6% 4 3 3 3 4 6% 43%	3480
	21st to end	Night	9% 4 2 4 3 3 3 3 5% 7% 58%	3817
April	1st to 10th	Night	9% 4 2 4 3 3 4 4 7% 8% 53%	2014
	11th to 20th	Night	12% 5% 2 5% 4 3 4 3 5% 6% 52%	1877
	21st to end	Night	11% 5% 1 4 2 4 3 3 5% 6% 54%	1900
May	1st to 10th	Night	13% 3 1 5% 3 3 3 4 6% 7% 51%	2980
	11th to 20th	Night	12% 4 2 5% 4 3 4 3 5% 6% 52%	2823
	21st to end	Night	7% 4 1 4 3 4 3 4 6% 9% 54%	3090
June	1st to 10th	Night	3 2 1 4 3 2 4 3 6% 10% 63%	1710
	11th to 20th	Night	2 1 1 3 3 4 3 4 6% 9% 64%	1710
	21st to end	Night	4 3 1 3 4 5% 5% 4 7% 12% 53%	1710
July	1st to 10th	Night	6% 3 2 4 3 3 3 3 5% 8% 60%	2850
	11th to 20th	Night	3 4 2 5% 4 4 5% 5% 7% 9% 53%	2850
	21st to end	Night	6% 3 1 4 3 3 4 4 5% 9% 57%	3433
August	1st to 10th	Night	1 1 2 2 1 2 2 4 7% 78%	3155
	11th to 20th	Night	2 2 1 3 2 3 4 4 5% 9% 65%	3113
	21st to end	Night	4 3 1 4 4 4 4 4 6% 11% 55%	3487
September	1st to 10th	Night	7% 6% 2 6% 4 5% 4 4 7% 9% 47%	2053
	11th to 20th	Night	10% 5% 2 5% 4 4 4 4 6% 9% 47%	2090
	21st to end	Night	10% 3 2 4 3 3 3 3 5% 8% 54%	2090
October	1st to 10th	Night	7% 4 1 3 2 3 3 2 5% 7% 62%	2090
	11th to 20th	Night	12% 4 2 4 2 2 3 2 4 5% 59%	2090
	21st to end	Night	8% 3 1 3 2 2 2 2 3 4 69%	2413
November	1st to 10th	Night	12% 5% 1 4 3 2 2 2 3 5% 59%	2380
	11th to 20th	Night	10% 5% 2 4 3 2 3 3 4 5% 59%	2470
	21st to end	Night	14% 5% 2 5% 3 3 3 3 5% 5% 51%	2470
December	1st to 10th	Night	14% 5% 1 4 3 3 3 2 4 6% 53%	2470
	11th to 20th	Night	15% 5% 2 5% 3 3 3 2 4 5% 52%	3036
	21st to end	Night	12% 4 2 4 2 3 4 3 4 8% 53%	4532

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 5% 12% 29% 25%	2854
	11th to 20th	Day	27% 3 4 17% 23% 25%	3170
	21st to end	Day	37% 4 9% 14% 27% 9%	3487
February	1st to 10th	Day	35% 4 7% 14% 20% 21%	1900
	11th to 20th	Day	33% 5% 6% 19% 20% 17%	1859
	21st to end	Day	28% 5% 8% 16% 25% 18%	1570
March	1st to 10th	Day	38% 6% 7% 15% 17% 17%	3156
	11th to 20th	Day	47% 4 6% 10% 16% 16%	3480
	21st to end	Day	28% 4 11% 17% 17% 23%	3814
April	1st to 10th	Day	33% 4 8% 18% 19% 18%	2159
	11th to 20th	Day	32% 5% 9% 18% 17% 19%	2254
	21st to end	Day	34% 5% 8% 18% 18% 17%	2280
May	1st to 10th	Day	40% 5% 8% 18% 16% 13%	3958
	11th to 20th	Day	34% 7% 9% 21% 17% 12%	4086
	21st to end	Day	33% 7% 10% 29% 16% 5%	4489
June	1st to 10th	Day	21% 6% 13% 30% 23% 6%	2470
	11th to 20th	Day	22% 6% 13% 27% 23% 8%	2470
	21st to end	Day	31% 7% 14% 24% 19% 6%	2470
July	1st to 10th	Day	28% 6% 13% 37% 15% 1	4056
	11th to 20th	Day	26% 7% 16% 33% 16% 3	4051
	21st to end	Day	25% 7% 14% 30% 21% 3	3994
August	1st to 10th	Day	9% 3 10% 41% 33% 3	3772
	11th to 20th	Day	14% 5% 21% 42% 16% 2	3762
	21st to end	Day	22% 8% 17% 26% 24% 3	4179
September	1st to 10th	Day	38% 8% 13% 19% 15% 7%	2124
	11th to 20th	Day	38% 7% 11% 20% 19% 4	2090
	21st to end	Day	28% 7% 11% 23% 18% 13%	2090
October	1st to 10th	Day	17% 4 6% 14% 20% 39%	3480
	11th to 20th	Day	34% 3 6% 12% 17% 27%	3458
	21st to end	Day	26% 3 5% 14% 38% 15%	3539
November	1st to 10th	Day	36% 4 8% 19% 20% 12%	1795
	11th to 20th	Day	34% 4 7% 18% 21% 16%	1710
	21st to end	Day	37% 4 7% 17% 18% 17%	1710
December	1st to 10th	Day	39% 4 5% 18% 22% 12%	1710
	11th to 20th	Day	37% 4 8% 16% 17% 19%	2159
	21st to end	Day	33% 3 4 16% 28% 15%	3135
January	1st to 10th	Night	25% 2 6% 13% 28% 25%	4108
	11th to 20th	Night	22% 2 4 18% 25% 30%	3822
	21st to end	Night	38% 4 5% 15% 25% 13%	4180
February	1st to 10th	Night	29% 4 8% 16% 18% 25%	2280
	11th to 20th	Night	32% 4 7% 19% 21% 19%	2218
	21st to end	Night	30% 5% 8% 15% 22% 20%	1884
March	1st to 10th	Night	31% 6% 10% 19% 18% 16%	3706
	11th to 20th	Night	43% 5% 8% 13% 16% 15%	3480
	21st to end	Night	26% 5% 11% 21% 17% 20%	3817
April	1st to 10th	Night	27% 6% 11% 19% 19% 19%	2014
	11th to 20th	Night	32% 6% 9% 17% 16% 20%	1877
	21st to end	Night	31% 5% 10% 21% 18% 15%	1900
May	1st to 10th	Night	32% 6% 11% 20% 18% 13%	3010
	11th to 20th	Night	31% 7% 10% 20% 19% 12%	2824
	21st to end	Night	25% 8% 14% 28% 19% 7%	3099
June	1st to 10th	Night	16% 7% 16% 31% 24% 6%	1710
	11th to 20th	Night	17% 5% 13% 28% 28% 8%	1710
	21st to end	Night	23% 8% 15% 27% 20% 6%	1710
July	1st to 10th	Night	23% 6% 17% 39% 14% 1	2805
	11th to 20th	Night	26% 8% 17% 28% 17% 4	2796
	21st to end	Night	22% 7% 17% 33% 20% 1	3324
August	1st to 10th	Night	9% 3 10% 42% 34% 3	3144
	11th to 20th	Night	16% 6% 22% 39% 14% 3	3143
	21st to end	Night	24% 7% 19% 26% 21% 3	3487
September	1st to 10th	Night	33% 8% 14% 21% 16% 8%	2053
	11th to 20th	Night	33% 7% 15% 21% 18% 5%	2090
	21st to end	Night	28% 5% 11% 23% 17% 15%	2090
October	1st to 10th	Night	17% 4 7% 16% 19% 37%	3480
	11th to 20th	Night	29% 3 6% 14% 18% 30%	3460
	21st to end	Night	17% 2 7% 15% 42% 17%	3962
November	1st to 10th	Night	30% 2 8% 19% 26% 15%	2380
	11th to 20th	Night	28% 3 9% 20% 22% 17%	2470
	21st to end	Night	34% 5% 8% 17% 19% 18%	2470
December	1st to 10th	Night	33% 4 8% 19% 20% 16%	2470
	11th to 20th	Night	35% 3 7% 16% 20% 19%	3037
	21st to end	Night	30% 5% 8% 15% 24% 19%	4532

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% 3 27% 34% 17% 1	270
	11th to 20th	Day	19% 7% 23% 33% 17% 1	270
	21st to end	Day	12% 10% 29% 33% 14% 2	297
February	1st to 10th	Day	20% 8% 23% 26% 18% 5%	270
	11th to 20th	Day	20% 8% 33% 24% 12% 3	270
	21st to end	Day	15% 10% 34% 28% 12%	225
March	1st to 10th	Day	17% 10% 34% 33% 5% 1	270
	11th to 20th	Day	17% 9% 33% 28% 13%	270
	21st to end	Day	13% 12% 32% 34% 9%	297
April	1st to 10th	Day	11% 11% 37% 33% 8%	339
	11th to 20th	Day	9% 12% 40% 32% 7%	452
	21st to end	Day	11% 8% 39% 33% 7% 1	460
May	1st to 10th	Day	14% 7% 33% 34% 10% 1	556
	11th to 20th	Day	13% 6% 31% 38% 11% 1	675
	21st to end	Day	15% 5% 24% 42% 14% 1	734
June	1st to 10th	Day	4 2 16% 50% 23% 4	680
	11th to 20th	Day	4 1 15% 50% 25% 4	680
	21st to end	Day	4 2 10% 41% 37% 7%	680
July	1st to 10th	Day	10% 1 5% 33% 43% 8%	671
	11th to 20th	Day	4 1 4 35% 47% 9%	668
	21st to end	Day	3 6% 35% 46% 10%	538
August	1st to 10th	Day	1 3 32% 48% 14%	487
	11th to 20th	Day	3 5% 30% 45% 17%	477
	21st to end	Day	4 1 4 32% 41% 18%	539
September	1st to 10th	Day	11% 1 2 24% 41% 21%	334
	11th to 20th	Day	6% 1 5% 18% 40% 31%	300
	21st to end	Day	7% 1 5% 21% 44% 22%	300
October	1st to 10th	Day	9% 2 9% 27% 41% 13%	300
	11th to 20th	Day	13% 2 9% 38% 30% 8%	300
	21st to end	Day	17% 7% 19% 33% 19% 5%	330
November	1st to 10th	Day	20% 5% 19% 27% 23% 6%	282
	11th to 20th	Day	23% 6% 11% 26% 25% 9%	270
	21st to end	Day	20% 6% 28% 29% 14% 3	270
December	1st to 10th	Day	22% 5% 18% 28% 19% 8%	270
	11th to 20th	Day	16% 10% 26% 25% 22% 1	270
	21st to end	Day	16% 5% 26% 29% 21% 3	297
January	1st to 10th	Night	15% 3 21% 46% 14% 1	950
	11th to 20th	Night	16% 4 19% 51% 11%	769
	21st to end	Night	17% 6% 23% 44% 9%	836
February	1st to 10th	Night	14% 6% 26% 43% 11%	760
	11th to 20th	Night	16% 7% 30% 40% 7%	744
	21st to end	Night	14% 6% 32% 44% 4	628
March	1st to 10th	Night	16% 7% 33% 37% 7%	745
	11th to 20th	Night	12% 9% 34% 40% 5%	570
	21st to end	Night	10% 7% 47% 31% 5%	627
April	1st to 10th	Night	9% 6% 43% 39% 3	570
	11th to 20th	Night	13% 7% 45% 32% 3	563
	21st to end	Night	12% 7% 46% 31% 4	570
May	1st to 10th	Night	8% 7% 45% 37% 3	570
	11th to 20th	Night	11% 5% 41% 36% 6%	561
	21st to end	Night	8% 5% 39% 39% 9%	617
June	1st to 10th	Night	2 2 27% 58% 10%	570
	11th to 20th	Night	3 1 29% 57% 9% 1	570
	21st to end	Night	4 1 19% 59% 17%	570
July	1st to 10th	Night	9% 1 12% 59% 18% 1	555
	11th to 20th	Night	3 1 10% 61% 24% 1	552
	21st to end	Night	4 1 11% 56% 27%	624
August	1st to 10th	Night	2 7% 61% 27% 2	567
	11th to 20th	Night	4 1 9% 51% 34% 1	564
	21st to end	Night	5% 1 7% 52% 32% 3	627
September	1st to 10th	Night	9% 2 5% 44% 36% 4	570
	11th to 20th	Night	10% 2 5% 42% 38% 3	570
	21st to end	Night	10% 1 8% 41% 36% 4	570
October	1st to 10th	Night	7% 2 9% 47% 35% 2	570
	11th to 20th	Night	13% 2 17% 41% 26% 1	570
	21st to end	Night	9% 4 18% 44% 23% 2	741
November	1st to 10th	Night	15% 3 13% 39% 28% 1	860
	11th to 20th	Night	13% 3 16% 42% 24% 2	950
	21st to end	Night	17% 5% 17% 43% 17% 1	950
December	1st to 10th	Night	17% 2 17% 43% 21% 1	950
	11th to 20th	Night	21% 5% 18% 41% 15%	950
	21st to end	Night	15% 5% 20% 45% 14% 1	1045

Page generated at 2024-11-03 01:11:24. Version ac07

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